Report of the Working Group on XXXXX (XXXX) - DOC
Shared by: aos51173
ICES Working Group Report 2006 | 1 Working Group Name: ICES/BSRP/HELCOM Workshop on Developing a Framework for Integrated Assessment for the Baltic Sea [WKIAB] Executive summary An ICES/BSRP/HELCOM Workshop on Developing a Framework for Integrated Assessment for the Baltic Sea [WKIAB] has been held in Tvärminne, Finland, from 1-4 March 2006. 18 scientists from 7 countries, well representing the participating organisations/projects, attended the meeting. The main objectives of the workshop, as reflected in the terms of references, were to (i) discuss different integrated assessment (IA) strategies/types and potential mutual benefits of a future cooperation between ICES and HELCOM, (ii) conduct trial IAs for sub-regions of the Baltic Sea, (iii) discuss monitoring strategies needed for a conducting IAs in the future, and (iv) discuss IA needs from ICES (science groups) and the consequences for the ICES Baltic committee expert group structure. Different views on IAs were discussed and close future cooperation between ICES and HELCOM in planning and conducting IAs was agreed. As a vehicle for this process a common Working Group on Integrated Assessments of the Baltic Sea (WGIAB) is envisaged to be established at the next ICES ASC. The group is supposed to communicate and coordinate activities within and between ICES and HELCOM, update ecosystem overview assessments on a regular basis for different subareas, conduct/contribute to HELCOM thematic assessments (e.g. pollution, eutrophication, impact of fisheries) and use ecosystem modelling in the assessment work. For the present workshop it was agreed to follow the approach for ecosystem overview assessments outlined by REGNS. Trial ecosystem overview IAs have been conducted for the Gulf of Riga (GOR) and Central Baltic Sea (CBS), the latter covering the Bornholm Basin, the Gdansk Deep and the Gotland Basin. Based on length of the covered period and consistency, time-series were identified to be used in an integrated analysis applying Principal Component Analyses (PCA). 39 (GOR) and 90 (CBS) time-series on biological, physical and chemical variables, covering in maximum the period 1973 (1974 for CBS) to 2004, were used in the analyses. For the GOR separate analyses of the ecosystem state and development were conducted fo Spring and Summer. For both seasons a regime shift in ecosystem state was observed after 1988. After a transition period lasting until 1991 or 1993 in spring and summer, respectively, a new regime was reached lasting until 2004. The new regime is characterized by high values for the Baltic Sea Index, air- and water temperatures leading in spring to large Acartia spp. and Eurytemora affinis populations as well as high herring (Clupea harengus) recruitment and biomass. In summer biological dynamics seemed to be unrelated to the change in the physical environment. Similar regime shifts as in the GOR were also observed in the CBS, displaying 3 regimes, i.e. 1974-87, 1988-93 and 1994-2004. The intermediate regime is characterized by low salinities and high temperatures, separates the high salinity and low temperature regime of the 1970s and 1980s from the high temperature and intermediate salinity regime since the mid 1990s. Biologically the CBS system changed from cod (Gadus morhua), herring and Pseudocalanus acuspes dominated to large populations sizes of sprat (Sprattus sprattus) and Acartia spp. The trial IAs proved the methodology to be capable of providing an integrated view on ecosystem state and development. Based on the time-series collected and the analysis conducted, short Ecosystem Status Reports have been produced to provide WGBFAS with 2 | ICES Working Group Report 2006 environmental information relevant to commercial fish stocks HELCOM with information on the effects of fishing on the Baltic Sea ecosystem. The results of the workshop indicated the need for revised monitoring strategies, covering key biological, chemical and physical variables. In addition a proposal for a revised structure for the ICES Baltic Committee expert groups was made, which has the goal to facilitate IAs in the future and to better implement the ecosystem approach for the Baltic Sea. ICES Working Group Report 2006 | 3 1 Opening of the meeting and adoption of the agenda An ICES/BSRP/HELCOM Workshop on Developing a Framework for Integrated Assessment for the Baltic Sea [WKIAB] (C. Möllmann, Denmark, B. Müller-Karulis, Latvia; A. Andrushaitis, BSRP, and Juha Flinkman, HELCOM) will held in Tvärminne, Finland, from 1-4 March 2006 to: a) develop a framework for an IA of the Baltic Sea, focusing on the role of the environment for fish and fisheries as well as the impact of fishing on the ecosystem, and considering the requirements of the HELCOM Monitoring and Assessment Strategy, the HELCOM Baltic Sea Action Plan, the European Marine Strategy and the UNEP Global Assessment of the State of the Marine Environment; b) review existing Integrated Assessments (IA) in the world‟s oceans and the suitability of their conceptual and methodological application for the Baltic Sea; c) review the information needs and data availability for IAs, with a view to establishing a metadatabase for key data series and creating a common network of expertise involving relevant ICES, HELCOM and BSRP groups; d) propose a future structure for the ICES Baltic Committee study/working groups and identify ToRs these groups should address to implement the ecosystem approach based on the information needs identified in ToR c); e) conduct trial IAs for selected sub-regions of the Baltic Sea as a basis for contributions to the Theme Session on “Integrated assessments in support of regional seas ecosystem advice - beyond quality status reporting” at the ICES ASC 2006; f) develop a monitoring strategy for future IAs taking into account existing monitoring programmes and involving relevant ICES, HELCOM and BSRP groups taking into account other international requirements (such as EU Directives), e.g. enhancing present fish surveys to ecosystem surveys, developing cost-effective methods of monitoring, and improving compatibility and integration of physical, chemical, biological and fisheries data sources; g) provide WGBFAS with environmental information relevant to commercial fish stocks; h) provide HELCOM with information on the effects of fishing on the Baltic Sea ecosystem. On behalf of the co-chairs, Christian Möllmann welcomed the participants (Annex 1) and introduced the agenda (Annex 2) for the workshop. The following 4 major objectives for the meeting were identified: (i) discuss different assessment strategies/types and potential mutual benefits between ICES and HELCOM for future cooperation; (ii) conduct trial Integrated Assessments (IA) for sub-regions of the Baltic Sea; (iii) discuss future monitoring strategies accomplishing the data needs of IAs and the ecosystem approach to fisheries; (iv) discuss IA needs from ICES (science groups) and the consequences for the ICES Baltic committee group structure. The first day of the workshop was devoted to presentations introducing the various IA activities of ICES, BSRP, HELCOM and BALTEX with a plenary discussion of these (section 2). Further statistical methodology useful for IAs was introduced and the data availability for the planned trial IAs was started. The work of the second day contained mainly data screening and first analysis of the data, with short interruptions for presentations on specific related topics. On the third day trial IAs were finished (section 3) and future monitoring strategies (section 5) as well as the future ICES Baltic committee expert group structure (section 4) were 4 | ICES Working Group Report 2006 discussed. The last day was devoted to reviewing the results of the trial IAs, discussing the future of WKIAB, drafting recommendations and new TORs. 2 Reviewing assessments (TORs a, b) The “Reviewing Assessments” session included presentations of the assessment strategies and work of ICES, HELCOM, BSRP and BALTEX, followed by discussions. Christian Möllmann introduced the integrated assessment work conducted in the North Sea. He emphasized that ecosystem-based fisheries management and/or ecosystem based management is increasingly important and that setting goals or objectives, establishing management protocols, and determining how close to the goals and objectives a system is requires that we know the STATUS OF LARGE MARINE ECOSYSTEMS, i.e. an Integrated Ecoystem Assessment (IEA). He pointed out that IEA can be seen as a process of actions which support „adaptive management and the ecosystem approach´, but also the combined numerical assessment of data and information from various sources (including monitoring and R&D programmes). The latter was the intention for initiating WKIAB. He then introduced the work and initial results of REGNS (Regional Ecosystem Study Group for the North Sea) within ICES., as well as the history of the approach in North America. He further showed the main trends in the Central Baltic ecosystem (from fish to phytoplankton) displaying the effects of fishing and climate and a resulting Regime Shift over all trophic levels in the late 1980s. Further there exists clear evidence for links between physics, zooplankton and fish growth and recruitment, but it remains unclear whether there is a strong link between eutrophication and commercial fish stocks. A conclusion from this was that although single trends and processess leading to the observed ecosystem dynamics are well known, an integrative analysis (over all trophic levels) of the functioning of the Baltic ecosystem and the influence of various natural and anthropogenic pressures has not been done yet. The major goal of WKIAB would thus be to start this process. If WKIAB would be successful, the process should be continued and a common ICES and HELCOM Study/Working Group should be establised which (i) communicates within and between ICES and HELCOM, (ii) updates integrated ecosystem assessments annually, (iii) conducts/contributes to thematic assessments (e.g. pollution, eutrophication, impact of fisheries), and (iv) uses ecosystem modelling in the future work. Juha-Markku Leppänen introduced the HELCOM strategy for Integrated Assessments. He pointed out that (i) assessment for HELCOM is a framework that should address objectives and targets set for the protection and conservation of the marine environment in a comparable way, (ii) different assessments which cover (parts) of a region and should be consistent for that region, (iii) assessments should be scientifically sound and aimed at the broadest level of acceptability possible, and (iv) assessment should be usable by several organisations. The objectives of HELCOM assessment activities are (i) to reveal how visions, goals and objectives are met, (ii) link the quality of environment to management and (iii) use performance indicators to assess how the objectives have been reached. The HELCOM assessment system is further based on Indicator Fact Sheets and discerns between Thematic Assessments (e.g. eutrophication, hazardous substances, maritime transport) and Holistic Assessments. A HELCOM concept for the latter are the planned Biodiversity Assessments, which are a concept for an IEA. These will integrate all ecosystem components (biotic and abiotic) and human pressures and will be the basis for management advice to reach sustainable use of the ecosystem goods and functions. Hans-Jörg Isemer introduced the BALTEX (Baltic Sea Experiment) project and its goals. He indicated that BALTEX shifts now from Phase 1 to Phase 2. Phase 1 had the goals ICES Working Group Report 2006 | 5 to explore and model the varios mechanisms determining the space and time variability of energy and water budgets of the BALTEX area and its interactions with surrounding regions, to relate these mechanisms to the large-scale circulation systems in the atmosphere and oceans over the globe, to develop transportable methodologies in order to contribute to basic needs of climate-, climate impact-, and environmental- research in other regions of the world. In Phase 2 BALTEX has now enlarged its focus with the following objectives: Better understanding of the energy and water cycles over the Baltic Sea basin; Analysis of climate variability and change since 1800, and provision of regional climate projections over the Baltic Sea basin for the 21st century; Provision of improved tools for water management, with an emphasis on more accurate forecasts of extreme events and long-term changes; Gradual extension of BALTEX methodologies to air and water quality studies; Strengthened interaction with decision-makers, with emphasis on global change impact assessments; Education and outreach at the international level. Hans-Jörg Isemer additionally presented the BACC-project (BALTEX Assessment of Climate Change for the Baltic Sea basin), which will assemble, integrate and assess available knowledge of past, current, and expected future climate change and its impacts on ecosystems in the Baltic Sea basin. The overall objective of BACC is to publish an assessment book by the year 2006. The unique feature of BACC is the integrated assessment of climate change and related both marine and terrestrial ecosystem changes. The material will be structured in chapters dealing with I. detection of past and ongoing climate change, II. projections of future climate change, and III. the impact of climate change on the regional environment, in particular both marine and terrestrial ecosystems. The overall project format is similar to the IPCC (Intergovernmental Panel on Climate Change), with author groups for the individual chapters, an overall summary for policy makers, and an external review process. BACC/BALTEX has also established a joint venture with HELCOM (The Baltic Marine Environment Protection Commission) in the sense, that the BACC material will be used for a two-volume HELCOM Thematic Assessment Report, to be published in 2006 and 2007. Finally Andris Andrushaitis reported news on the state and future for the BSRP. Presently the 2nd phase of the project is in planning although the funding is not assured yet. He further reported on the achievements of the project and on the assessment work which is tightly connected to the work of HELCOM. The discussions during this session clearly demonstrated the different approaches of especially ICES and HELCOM. Whereas the ICES IA-work is presently mainly focusing on evaluation of development and state of an ecosystem, HELCOM considers IA as a full management framework. Consensus was derived that a full management framework will be the future goal of both parties and that the approach of WKIAB, to conduct trial IAs using multivariate statistical methodology, is an important starting point. It was agreed that future activities in this direction should be better coordinated and that a common working group would be the forum of choice to do so. Further the work of BALTEX was considered as an important contributor to future Baltic IAs and a further cooperation was agreed. ICES Working Group Report 2006 | 6 3 Trial integrated assessments Summary here – results as Ecosystem Overview Document in Annex 4 Future structure of Baltic committee expert groups On the workshop the potential future structure for the ICES Baltic Committee study/working groups was discussed (TOR d). Background of this TOR are discussions on a joint meeting of SGMAB and SGBFFI in Riga, June 2005 which resulted in a Non-Paper discussed on the ICES ASC in Aberdeen, September 2006 (see Annex 5). In summary, these discussions indicated the need to re-organise the Baltic Sea research within ICES. Some of the main arguments for re-organising the expert group structure were: the need for advancing towards an Integrated Assessment (IA) of the Baltic Sea ecosystem similar as initiated for the North Sea (i.e. REGNS), as a basis for implementing the Ecosystem Approach to Fisheries Management (EAF); the need for an improvement of co-ordination of the WG/SG-work with other environmental organisations (e.g. HELCOM, EU Marine Strategy); WKIAB thus became the duty to come up with a suggestion for a new structure which is outlined in Fig. 4.1. The center of this structure is the established of a “Working Group on Integrated Assessments of the Baltic Sea” [WGIAB], which will be the counterpart to the present fisheries assessment groups [FAWGs, i.e. WGBFAS and WGBAST]. Both groups should be supported by observational data from an “Ecosystem Survey Working Group” [ESWG]. This group will be central in implementing the IA and the EAF as it should develop in cooperation with HELCOM the present trawl and hydroacoustic surveys into ecosystem surveys which provide both “tuning” and “ecosystem” data (see section 5). The work of the assessment groups should be scientifically supported by 3 SGs, the SG for Baltic Fish Ecology (SGBFE), the SG on Baltic Productivity (SGPROD), and the SG on Baltic Ecosystem Health (SGEH). WKs SGBFE SGPROD SGEH FA WG(s) WGIAB ES WG Fig. 4.1 Suggestion of a new structure for the ICES Baltic Sea assessment and scientific activities. [SGBFE-Study Group on Baltic Fish Ecology, SGPROD – Study Group on Baltic Productivity, SGEH – Study Group on Ecosystem Health, FAWGs-Fish stock Assessment Working Groups (WGBFAS and WGBAST), WGIAB-Working Group on Integrated Assessments of the Baltic Sea, ESWG - Ecosystem Survey Working Group, WK – Workshops]. ICES Working Group Report 2006 | 7 SGBFE will be the result of merging the present groups SGMAB, SGBFFI and SGABC. SGBFE should deal with all issues related to commercially important Baltic fish species, but especially (i) conduct bi-annual multispecies assessments providing natural mortality rates of cod, herring and sprat for WGBFAS, and (ii) coordinate issues related to age-reading problems of cod and sprat. It was proposed to shift the work on local, coastal fish stocks conducted within SGBFFI, to the respective HELCOM group, to not double the work. SGPROD and SGEH should continue their successful work on ecosystem issues conducted in the frame of BSRP, independent of the future of the project. SGPROD should focus on lower trophic level dynamics related to the physical and chemical environment, and linking these to fish population dynamics. SGEH should e.g. continue its work of the DPSIR framework of indicators, the development of various biological indices and on biological effects of harmful substances. The work of these groups is of special importance for implementing the ecosystem approach. A major task of these groups will be further to facilitate the communication to scientific activities outside ICES, e.g. to EU-funded projects and to HELCOM and BALTEX. Ecosystem modelling issues, as presently dealt with in SGBEM, were also considered to be crucial for implementing the ecosystem approach. However, a group working separate from groups dealing with the biological and ecological questions was considered as sub-optimal. Therefore ecosystem model issues should be a crucial task in all the SGs to be formed. Cross- group modelling efforts should be conducted using targeted workshops. The latter are generally considered as an underrepresented tool in the present system. Therefore the more frequent use of workshops dealing with up-to-date problems or “hot-topics” is encouraged. Targeted workshops are considered of being more effective as e.g. establishing new SGs for special questions, which will increase the number of permanent groups and the work load of many scientists. The most important change in the structure will be the implementation of a WGIAB. This will (i) assure the conservation, further development and the integration of the work done within BSRP in the broader scientific community, (ii) fullfill the request for an IA, which (iii) enables ICES to react on the new requirements in terms of advice which is due to the change in the management system of the Baltic and European waters. A special task for all SGs should be therefore to support and react to the work of WGIAB. This is first of all to provide quality checked indicator time-series for future IAs, but also the support in terms of methodological and scientic expertise. ICES Working Group Report 2006 | 8 5 Future monitoring strategy The Baltic Sea is a well monitored marine ecosystem. However, data are collected under a variety of programmes for specific purposes. There is often little data exchange between different monitoring programmes and institutions involved, but integrated assessment (IA) demands collection of data on all ecosystem components and their driving factors. In the following, we suggest a strategy for IA that makes use of data collected in existing Baltic Sea monitoring programmes and identify gaps that require additional monitoring efforts. We also describe the requirements for data exchange to enable IAs timely. Existing Baltic Sea monitoring programmes Currently, in the open sea Baltic monitoring programmes are focused on the effects of eutrophication and hazardous substances (HELCOM COMBINE) as well as on fishery management (European Council regulation 1543/2000). Major Baltic Sea status assessments are the annual fish stock assessments conducted by ICES working groups, and the HELCOM assessments of eutrophication and biodiversity, the later covering longer time periods and are planned to be updated in 2009 and 2010, respectively. Additional monitoring requirements are created by the EU Habitats and Birds directives and in the future also by the upcoming EU Marine Strategy. Further, in coastal and transitional waters, the EU Water Framework Directive (WFD) demands extensive data collection on biological and chemical parameters and regular assessment of ecological status. The WFD includes fish only in transitional area, but HELCOM COMBINE also contains a coastal fish monitoring programme. Monitoring programmes and the requirements of the individual assessments are briefly described in annex 6. Data requirements for integrated assessment While the HELCOM monitoring programme describes the lower trophic level of the ecosystem (hydrography, nutrients, phytoplankton, zoobenthos), the upper trophic level (fish, fishery) is mainly described by the EU fisheries data collection programme. Additional monitoring for integrated assessments should focus on parameters and processes not covered well in these programmes. These are primarily mesozooplankton, macrozooplankton, fish stomach content, and to a lesser degree macrozoobenthos. Mesozooplankton links fish to the lower parts of the foodweb, both as the food source for planktivorous fish (herring, sprat), but also as the food supply of larvae for other fish species. Therefore mesozooplankton information at the time of nauplii hatching could improve recruitment predictions. Spawning and nauplii hatching time varies between species and Baltic Sea regions. Zooplankton biomass in May would provide information relevant for the recruitment success of many species. For planktivorous fish, zooplankton information is also useful at the time of intensive feeding (August – October). Zooplankton monitoring could be a combined effort between eutrophication and fishery monitoring programmes, but the primary demand is as a food source for fish larvae and planktivorous fish and therefore zooplankton data should be intensified by fisheries groups. Currently, long-term data in the open Baltic exist primarily from the Latvian Fish Resources Agency, while within HELCOM COMBINE, mesozooplankton is only a voluntary parameter. Data is not compatible between different sources, as different gears (WP2, Juday net) and mesh sizes are used. On the other hand, existing long-term data series should be continued without change of gear. Technically, zooplankton data collection can be included into fisheries surveys, when sufficient winch capacity exists. Considering the timing of spawning and feeding of the major fish species, we suggest that zooplankton data collection should be included into fishery surveys conducted in April/May and during summer surveys (August – October). ICES Working Group Report 2006 | 9 In coastal areas zooplankton monitoring is not included into the WFD monitoring requirements. On the other hand, coastal areas are important fish nursery areas. Monitoring efforts for coastal fish and WFD/Habitat directive requirements should be coordinated nationally, ensuring that areas overlap and where relevant, zooplankton data should be included into monitoring in coastal areas. It was also noted that current coastal fish monitoring does not provide information suitable for biodiversity assessment, since not all coastal fish are sampled by the current method. At the same time, continued funding has to be assured for the programme, potentially by including the coastal fish monitoring into the EU funded fisheries survey programme. Macrozooplankton is an important food source for e.g. Baltic herring. Data on this food web component is scarce, since it is not included into routine monitoring programmes. No harmonized sampling methods exist. For both meso- and macrozooplankton, hydroacoustic methods for abundance determination are currently under development. The use of these methods during routine fishery surveys should investigated. Macrozoobenthos is the chief food source of flatfish species (e. g. flounder), but is also consumed by demersal species (e. g. cod) and coastal fish. In addition, it is a food source for birds in coastal areas. The links between macrozoobenthos consumers and their prey and the type of information needed to integrate the status of macrozoobenthic prey into fisheries management could not be addressed at the workshop yet. However, there was agreement that macrozoobenthos sampling cannot be integrated into routine fisheries surveys as the sampling is time consuming and would require additional shiptime. To increase the knowledge of predator-prey relations in the Baltic, stomach sampling and analysis of stomach content should be included into routine fisheries surveys. Sample collection does not require additional shiptime and samples can be preserved and analyzed in the laboratory. However, funding and technical capacity for sample analysis has to be ensured. CTD casts should be routinely included into fisheries surveys, including also dissolved oxygen and chlorophyll a measurments. Temperature, salinity and oxygen influence fish feeding and reproduction and affect their spatial distribution. It is technically feasible to include a CTD casts at each haul station during trawl and hydroacoustic surveys. The high spatial density of sampling greatly increases the precision of spatially averaged indicators as for example the spawning volume of cod. Phytoplankton information is currently sparse in the Baltic Sea. Including chlorophyll a sensors into CTDs used on fishery surveys would increase the density of observations available in the Baltic Sea at very little additional cost. Other promising phytoplankton indicators are produced by ships of opportunities, since their temporal and spatial resolution is sufficient to monitor key phytoplankton processes like the spring bloom (see appendix xxx). Also nutrient analysis can technically be included into fishery surveys. If a rosette sampler is available, the additional ship time requirement for water sample collection is small. However, nutrient analyses have to be conducted on board immediately after sampling. They require therefore additional personnel (1 – 2 persons) and laboratory space. Because nutrient fields are monitored extensively under HELCOM COMBINE, we do not suggest to add nutrient sampling to fisheries surveys, but rather to strengthen the data exchange between the different Baltic Sea monitoring programmes. Also HELCOM COMBINE surveys can technically be expanded to include fish monitoring, when free capacity on research vessels is available. Information on planned cruises should be exchanged between HELCOM and fishery monitoring communities to ensure that vessel capacity is used most efficiently. ICES Working Group Report 2006 | 10 Data exchange and timely data delivery IA should provide an ecosystem status description to be used e.g. by fisheries assessment working groups. This implies that IAs will have to be conducted annually, based on the data of the previous year, during early spring (February, March), which presently creates timing problems in the dataflow of many parameters. Analysis of biological parameters like phytoplankton and zooplankton biomass/species composition, for which samples can be preserved, might not be completed yet. Reporting of data – nutrients, hydrography, biota – to databases has to be accelerated. Finally, data policies have to be harmonized and permission to use monitoring data collected in different programmes have to be obtained. IA should be based on time-series that characterize key ecosystem processes. Aggregating of raw data into indicators and time series should be handled by experts in the relevant fields who should be involved in the entire IA processes. Expert involvement is crucial to data quality control, indicator selection, and to reducing data variability by spatial/temporal averaging, as well as to interpreting IA results. Raw data used in IAs should be stored in a database system that ensures their operational availability. The database should also include information on data quality. ICES Working Group Report 2006 | 11 Annex 1: List of participants NAME ADDRESS PHONE EMAIL Christian Möllmann Danish Institute for +45 3396 3458 firstname.lastname@example.org (Co-chair) Fisheries Research, Charlottenlund Castle, DK-2920 Charlottenlund Bärbel-Müller Karulis Institute of Aquatic ????????????? email@example.com (Co-chair) Ecology, Daugavgrivas 8, LV-1048 Riga Andris Andrushaitis Institute of Aquatic + 371 7610851 firstname.lastname@example.org (Co-chair) Ecology, Daugavgrivas 8, LV-1048 Riga Juha Flinkman (Co- Finnish Institute of +358 40 7503911 Juha.email@example.com chair) Marine Research, P.O. Box 2, FIN-00561 Helsinki Johan Modin Swedish Board of +46 17346463 Johan.firstname.lastname@example.org Fisheries, SE-74071 Öregrund Gedas Vaitkus Institute of Ecology, +370 699 99940 email@example.com Akademijos 2, LT- 08412 Vilnius Eugeniusz Sea Fisheries Institute, +48 587356146 firstname.lastname@example.org Andrulewicz Kollataja 1, PO-81-332 Gdynia Elsbieta Lysiak- Institute of Ecology +48 58 62 88 252 Elsbieta.Lysiak- Pastuszak and Water Pastuszak@imgw.pl Management, ul. Waszyngtowa 42, PO- 81-342 Gdynia Hartmut Heinrich Bundesamt für +49 40-3190 3510 Hartmut.email@example.com Seeschifffahrt und Hydrografie, Bernhard- Nocht-Str. 78, D- 20359 Hamburg Rabea Diekmann Institute for +49 40 42838 6621 Rabea.diekmann@uni- Hydrobiology and hamburg.de Fisheries Science, Olbersweg 24, D- 22767 Hamburg Yvonne Walther Swedish Board of +46 455 362852 Yvonne.firstname.lastname@example.org Fisheries, Utövägen 5, SE-37137 Karlskrona Maris Plikshs Latvian Fish Resources +371 7610 766 Maris.email@example.com Agency, Daugavgrivas 8, LV-1048 Riga Heikki Peltonen* Finnish Environment +358-9-40300236 firstname.lastname@example.org Institute, P. O. Box 140, FIN-00251 HELSINKI, Pirjo Kuuppo * P.O. Box 140; +358-400-232342 Pirjo.email@example.com Mechelininkatu 34A; FIN-00251 Helsinki Juha-Markku Katajanokanlaitura 6B, +358-207-421 627 Juha- Leppänen* FIN-00160nHelsinki firstname.lastname@example.org Hermanni Backer* Katajanokanlaitura 6B, +358-207-421 627 Hermanni.Backer@helcom.fi FIN-00160nHelsinki 12 | ICES Working Group Report 2006 Hans-Jörg Isemer* GKSS +49 4152 87 1661 email@example.com Forschungszentrum Geesthacht GmbH, International Projects Department SEP, International BALTEX Secretariat, Max- Planck-Str. 1, D-21521 Geesthacht Seppo Kaitala* Finnish Institute of +358-9-61394417 Seppo.Kaitala@fimr.fi Marine Research Erik Palménin aukio 1 (P.O. Box 2), FIN- 00561 Helsinki * part-time ICES Working Group Report 2006 | 13 Annex 2: Agenda Wednesday 1 March 0900 – 0930 Welcome, practical information, introduction to the workshop 0930 – 1600 Session on REVIEWING ASSESSMENTS Presentations: 1. Integrated assessments within a fisheries management context – lessons for the Baltic Sea (Christian Möllmann) 2. The HELCOM assessment strategy for integrated assessment (Juha-Markku Leppänen) 3. Assessment of Climate Change for the Baltic Sea basin - The BACC Project (Hans-Jörg Isemer) 4. The Baltic Sea Regional Project and Ecosystem assessments (Andris Andrushaitis) 1615 - 1800 Session on DATA AVAILABILITY 1. Presentation on statistical methodology for integrated assessments (Rabea Diekmann) 2. The use of indicators for evaluation of trends in the Balticb (Seppo Kaitala) – see Annex 7 Thursday 2 March 0900 – 1030 Session on DATA AVAILABILITY 3. Regional Databases on the Baltic GIS Portal - Baltic Sea Regional Project GIS CC (Gedas Vaitkus) 4. An integrated ichthyological-chemical-biochemical approach to assess the impact of the environmental quality status of selected marine sites on ichthyofauna health (Eugeniusz Andrulewicz) 5. Effects of Eutrophicationon Baltic Fish and Fisheries (Eugeniusz Andrulewicz) 1045 – 1800 Session on TRIAL INTEGRATED ASSESSMENTS Friday 3 March 0900 – 1030 Review session on the TRIAL INTEGRATED ASSESSMENTS 1045 - 1200 Review session on the TRIAL INTEGRATED ASSESSMENTS cont. and session on STRUCTRE 1400 - 1600 Review session on the TRIAL INTEGRATED ASSESSMENTS cont. and session on MONITORING 1615 - 1800 PLENARY SESSION summarizing the results Saturday 4 March 0900 - 1030 REPORTING group work 1045 – 1200 Summary and closing of the workshop ICES Working Group Report 2006 | 14 Annex 3: Me tadata- Table of time -series available for Trial Integrated Assessments Annex-Table 3.1. Time-series used in the Trial Integrated Assessment of the Central Baltic Sea. Variable Abbreviation Unit Area Season Source Central Sprat landings SPRland tonnes Annual ICES Baltic * Herring Central HERland tonnes Annual ICES landings Baltic * Flounder Central FLOland tonnes Annual ICES landings Baltic * Central Cod landings CODland tonnes Annual ICES Baltic * Sprat No age 1 Central SPRR1 Annual ICES recruitment (10³) Baltic Herring No age 1 Central HERR1 Annual ICES recruitment (10³) Baltic Flounder No age 3 Central FLOR3 Annual ICES recruitment (10³) Baltic Cod No age 2 Central CODR2 Annual ICES recruitment (10³) Baltic Central Sprat SSB SPRSSB tonnes Annual ICES Baltic Central Herring SSB HERSSB tonnes Annual ICES Baltic Central Flounder SSB FLOSSB tonnes Annual ICES Baltic Central Cod SSB CODSSB tonnes Annual ICES Baltic Sprat fishing Central SPR_F3-5 age 3-5 Annual ICES mortality Baltic Herring Central fishing HER_F3-6 age 3-6 Annual ICES Baltic mortality Founder Central fishing FLOF4-6 age 4-6 Annual ICES Baltic mortality Cod fishing Central CODR4-7 age 4-7 Annual ICES mortality Baltic Central Sprat weight SPRWC3 kg (age 3) Annual ICES Baltic Central Herring weight HERWC3 kg (age 3) Annual LATFRA Baltic Flounder Central FLOWC3 kg (age 3) Annual LATFRA weight Baltic Central Cod weight CODWC3 kg (age 3) Annual LATFRA Baltic Salmon Central SALCAT tonnes Annual LATFRA landings Baltic Central Salmon weight SALW3 kg (age 3) Annual LATFRA Baltic Swedish Perch cpue PERCPUE No/net/night Annual LATFRA coast White bream Swedish WBRCPUE No/net/night Annual SBFÖ cpue coast ICES Working Group Report 2006 | 15 Variable Abbreviation Unit Area Season Source Swedish Roach cpue ROACPUE No/net/night Annual SBFÖ coast Swedish Ruffe cpue RUFCPUE No/net/night Annual SBFÖ coast Coastal fish No of Swedish species Coast1Rich Annual SBFÖ species coast richness Shannon- Coastal fish Swedish Coast1ShWi Wiener Annual SBFÖ diversity coast Index Cod Central reproductive REPVOL Km3 Annual IFM Baltic volume Acartia spp. Central Acartia_Spr mg*m-3 Spring LATFRA biomass Baltic Ø Acartia spp. Central Acartia_Sum mg*m-3 Summer LATFRA biomass Baltic Temora Central longicornis Temora_Spr mg*m-3 Spring LATFRA Baltic biomass Temora Central longicornis Temora_Sum mg*m-3 Summer LATFRA Baltic biomass Pseudocalanus Central acuspes Pseudo_Spr mg*m-3 Spring LATFRA Baltic biomass Pseudocalanus Central acuspes Pseudo_Sum mg*m-3 Summer LATFRA Baltic biomass Bosmina Central longispina Bosmina_Sum mg*m-3 Summer LATFRA Baltic biomass Synchaeta sp. Central Sync_Spr mg*m-3 Spring LATFRA biomass Baltic Synchaeta sp. Central Sync_Sum mg*m-3 Summer LATFRA biomass Baltic Central Secchi depth SB_Secchi M Summer ICES Baltic Bornholm Bottom PO4 PO4_BBWinBot µmol*l-1 Winter ICES Basin Bornholm Bottom NO3 NO3_BBWinBot µmol*l-1 Winter ICES Basin Bornholm Bottom NH4 NH4_BBWinBot µmol*l-1 Winter ICES Basin Bornholm Bottom O2 O2_BBWinBot µmol*l-1 Winter ICES Basin Bornholm Surface PO4 PO4_BBWinSur µmol*l-1 Winter ICES Basin Bornholm Surface NO3 NO3_BBWinSur µmol*l-1 Winter ICES Basin Gotland Chlorophyll a Chla_GBSpr mg*m-3 Spring ICES Basin Gotland Chlorophyll a Chla_GBSum mg*m-3 Summer ICES Basin Bornholm Chlorophyll a Chla_BBSpr mg*m-3 Spring ICES Basin Bornholm Chlorophyll a Chla_BBSum mg*m-3 Summer ICES Basin 16 | ICES Working Group Report 2006 Variable Abbreviation Unit Area Season Source Inflow Central inflow Km3 Annual IOW strength Baltic Bornholm Diatoms Bac_BBSpr mg*m-3 Spring ICES Basin Bornholm Dinoflagellates Dino_BBSpr mg*m-3 Spring ICES Basin Bluegreen Bornholm Cyano_BBSpr mg*m-3 Spring ICES algae Basin Bornholm Diatoms Bac_BBSum mg*m-3 Summer ICES Basin Bornholm Dinoflagellates Dino_BBSum mg*m-3 Summer ICES Basin Bluegreen Bornholm Cyano_BBSum mg*m-3 Summer ICES algae Basin Gotland Diatoms Bac_GBSpr mg*m-3 Spring ICES Basin Gotland Dinoflagellates Dino_GBSpr mg*m-3 Spring ICES Basin Bluegreen Gotland Cyano_GBSpr mg*m-3 Spring ICES algae Basin Gotland Diatoms Bac_GBSum mg*m-3 Summer ICES Basin Gotland Dinoflagellates Dino_GBSum mg*m-3 Summer ICES Basin Bluegreen Gotland Cyano_GBSum mg*m-3 Summer ICES algae Basin Central Runoff RunOff m3*s-1 Annual SMHI Baltic Gotland Surface PO4 PO4_GBWin_0-10 µmol*l-1 Winter ICES Basin Gotland Surface NO3 NO3_GBWin_0-10 µmol*l-1 Winter ICES Basin PO4_GBWin_100- Gotland Midwater PO4 µmol*l-1 Winter ICES 120 Basin NO3_GBWin_100- Gotland Midwater NO3 µmol*l-1 Winter ICES 120 Basin NH4_GBWin_100- Gotland Midwater NH4 µmol*l-1 Winter ICES 120 Basin PO4_GBWin_200- Gotland Bottom PO4 µmol*l-1 Winter ICES 220 Basin NH4_GBWin_200- Gotland Bottom NH4 µmol*l-1 Winter ICES 220 Basin Gdansk Surface PO4 PO4_GDWin µmol*l-1 Winter ICES Deep Gdansk Surface NO3 NO3_GDWin µmol*l-1 Winter ICES Deep Depth of 11 Gotland 11psu_GBAnn m Annual LATFRA psu isoline Basin Gotland SST + T_GBSpr_0-10 °C May ICES Basin Midwater Gotland T_GBSpr_40-60 °C May ICES temperature Basin Gotland SST S_GBSpr_0-10 psu May ICES Basin Deepwater Gotland S_GBSpr_80-100 psu May ICES temperatre Basin Gotland SST T_GBSum_0-10 °C August ICES Basin ICES Working Group Report 2006 | 17 Variable Abbreviation Unit Area Season Source Midwater Gotland T_GBSum_40-60 °C August ICES temperature Basin Gotland SSS + S_GBSum_0-10 psu August ICES Basin Deepwater Gotland S_GBSum_80-100 psu August ICES salinity Basin Maximum ice Central MaxIce Km² Annual ICES cover Baltic Bornholm SSS S_BBSpr_0-10 psu Spring ICES Basin Deepwater Bornholm S_BBSpr_70-90 psu Spring ICES salinity Basin Bornholm SST T_BBSpr_0-10 °C Spring ICES Basin Bornholm SST T_BBSum_0-10 °C Summer ICES Basin Midwater Bornholm T_BBSpr_40-60 °C Spring ICES temperature Basin Swedish SST T_CoastSum_Sur °C August ICES Coast Baltic Sea Central BSI Winter IFM Index Baltic Breeding Central success White- breedsucc % Annual SMNH Baltic tailed eagle * fish data from the following ICES assessment units: Sprat Subdivisions 22 to 32, Subdivisions 25 to 29 and 32 excl. Gulf of Riga, Flounder Subdivisions 24 & 25, Cod Subdivisions 25 to 32. + SST – Sea Surface Temperature, SSS – Sea Surface Salinity ø Zooplankton data are from the Gdansk Deep and Gotland Basin ICES Working Group Report 2006 | 18 Annex-Table 3.2. Time-series used in the Trial Integrated Assessment of the Gulf of Riga. Variable Abbreviation Unit Season Source Acartia spp. Acartia mg*m-3 Annual LATFRA biomass Eurytemora Eurytemora mg*m-3 Annual IAE affinis biomass Limnocalanus grimaldii Limnocalanus mg*m-3 Annual IAE biomass Cladoceran CLADOCERA mg*m-3 Annual IAE biomass Synchaeta sp. Synchaeta mg*m-3 Annual IAE biomass Rotatorian ROTATORIA mg*m-3 Annual IAE biomass Cercopagis Cercopagis mg*m-3 Annual IAE pengoi biomass Secchi depth Secchi m Spring IAE Secchi depth SSecchi m Summer IAE Chlorophyll a Chla mg*m-3 Spring IAE Chlorophyll a SChla mg*m-3 Summer IAE Herring RecCur No age 1 Annual ICES recrruitment Herring biomass Herring tonnes Annual ICES Herring Catch tonnes Annual ICES landings Herring weight HerWeight kg Annual ICES Herring fishing F (3-7) age 3-7 Annual ICES mortality Cod landings Codcatch tonnes Annual ICES Airtemperatire AirTemp °C February LATFRA Winter Tfeb °C Febuary LATFRA temperature Spring TMay20 °C May LATFRA temperature Summer TAug20 °C August LATFRA temperature Spring salinity SalMay20 psu May LATFRA Summer salinity SalAug50 psu August LATFRA PO4 PO4 µmol*l-1 Annual IAE NO4 NO23 µmol*l-1 Annual IAE Runoff RunoffJanAug m3*s-1 January-August IAE DIN load DIN load µmol*l-1 previous year IAE previous year previous DIN load µmol*l-1 January-August IAE Baltic Sea Index BSI Winter IFM Abbreviations: ICES – from ICES data centre; LATFRA – Latvia Fish Resources Agency, SBFÖ – Swedish Board for Fisheries Öregrund; IFM – Leibniz Institute for Marine Science Kiel, IOW – Leibnitz Institute for Baltic Sea Research; SMHI – Swedish Meterological and Hydrological Institute, SMNH – Swedish Museum for Natural History; IAE – Institute for Aquatic Ecology Riga. ICES Working Group Report 2006 | 19 Annex 4: State of the Baltic ecosyste m Introduction This document summarizes the state and development of two Baltic Sea subsystems, i.e. the Central Baltic Sea (CBS; incl. the Bornholm Basin, the Gdansk Deep, and the Gotland Deep – ICES Subdivisions 25, 26, 27 and 28) and the Gulf of Riga (GOR), during 1974 to 2004. It is an output of the ICES “ICES/BSRP/HELCOM Workshop on Developing a Framework for Integrated Assessment for the Baltic Sea [WKIAB]” and meant to provide background environmental information for the ICES assessment work (e.g. WGBFAS, WGBAST), but also information on the effects of fishing on the Baltic ecosystem for HELCOM. This status report comprises information on the development of (i) the climate over the Baltic Sea area with resulting changes in the hydrography, (ii) the nutrient loads, (iii) the phyto- and zooplankton populations, and (iv) the major fish stocks and their fisheries, and (v) a bird population. Finally multivariate analyses of all time-series are presented, providing an integrated view on changes of the ecosystem structure and functioning. Of the time-series which were available to the workshop, only those with a sufficient temporal coverage were used in this status report as well as in multivariate analyses (see below). Although consequently potentially important components of the ecosystem are not represented (e.g. macrozooplankton, benthos), the report is believed to give a sufficiently broad overview of the ecosystems. In the future, lacking ecosystem components will be included, if data are made available. A description of the time-series used and their sources is given in Annex 3. Multivariate analyses (Integrated analysis) To provide an integrated view on the state and development of the CBS and the GOR, multivariate analyses were conducted on the available time-series. All data-series available had a frequency or were compiled to one assessment per year and covered in maximum the period 1973 to 2004. In total 90 variables were considered in an “annual” analysis of the CBS. The GOR datasets were separated into spring and summer measurements. In total 22 variables were used in a “spring” analysis and 23 variables in a “summer” analysis. Time series were analysed by Principal Component Analysis (PCA). To improve linearity between variables and reduce the relationship between the mean and the variance some of the variables were ln(x+1) transformed. Subsequently a standardized PCA based on the correlation matrix was performed on the transformed values. Variable vectors and scores (years) were displayed on the first factorial plane and the years were connected in chronological order. Year scores along PC1 and PC2 were additionally plotted against time to detect possible regime shifts. Finally the raw values of each variable were categorised into quintiles and each quintile was given a specific colour, following the traffic light framework used in stock assessments (Link et al. 2002). The variables were sorted according to their loadings along the first PC to detect systematic patterns in the time series. ICES Working Group Report 2006 | 20 Central Baltic Sea (CBS) Climate and hydrography The development of the climate over the Baltic Sea area in the last 3 decades is displayed by the Baltic Sea Index (BSI), which is well correlated with the Index of the North Atlantic Oscillation (NAO) (Lehmann et al. 2002). While during the 1970s and 1980s the index was mainly in a negative state, it was mainly positive afterwards (Fig. CBS-1). This change in sign of the index was associated with more frequent westerly winds, warmer winter and eventually a warmer climate over the area. This is very well demonstrated by the convincing correlation fo the BSI with the maximum ice extend in the Baltic (r=0.84). Time-series of water temperatures in the Bornholm (BB) and Gotland Basin (GB) in spring and summer reflect this warming during the 1990s. 0.4 300 Ice BSI 200 Maximum Ice Extend 0.2 100 (km2) BSI 0.0 0 -100 -0.2 -200 -0.4 -300 8 GB_surface Spring 6 GB_midwater BB_surface 4 BB_midwater 2 0 Temperature anomaly -2 -4 (deg C) 4 2 0 -2 -4 Summer 1975 1980 1985 1990 1995 2000 2005 Fig. CBS-1. Time-series on the Baltic Sea Index (BSI), maximum ice extend, and temperatures in the Bornholm Basin (BB) and the Gotland Basin (GB). Beside the influence on the thermal conditions, climate also influences the salinity in the Central Baltic Sea (Fig. CBS-2). During the high BSI-period since the late 1980s only 2 major Baltic inflows were recorded. The absence of major inflow events to the Baltic since the 1980s, although unpredictable to date, has been hypothesized to be related to the high NAO period (Hänninen et al. 2000). Increasing runoff leading to sea level variations may have hindered major inflow events (Matthäus and Schinke 1999). However, no increase in runoff has been recorded during the last 30 years (Fig. CBS-2). Deep water salinity has clearly decreased during the low inflow frequency until 1993, demonstrated by the depth of the 11psu isoline in the GB and the bottom salinity in the both BB and GB. During the last decade deep ICES Working Group Report 2006 | 21 water salinity was on a higher level again, especially after the 2003 inflow. Surface salinity in both basins continuously declined due to increased precipitation (Hänninen et al. 2000). inflow runoff depth of 11 psu in GB BSI 40 0.4 0 40 30 0.2 50 20 Runoff (km3) Depth (m) Inflow 100 BSI 20 0.0 0 150 10 -0.2 -20 200 0 -0.4 -40 3 2 Salinity (psu) 1 0 -1 GB_bottom -2 GB_surface BB_bottom BB_surface -3 1975 1980 1985 1990 1995 2000 2005 Fig. CBS-2. Time-series on the Baltic Sea Index (BSI), runoff, depth of the 11psu isoline in the Gotland Basin (GB), and salinity in the Bornholm Basin (BB) and the Gotland Basin. Nutrients Surface winter PO4 showed a similar trend in both the Bornholm and the Gotland Basin (Fig. CBS-3). Decreasing trends at the end of the 1970s were followed by high PO 4 levels during 1980s and early 1990s. After a pronounced drop in PO 4 surface concentrations, values were on an intermediate level recently. Winter PO4 bottom concentrations were mainly higher in the Gotland Basin. Values were increasing in the Gotland Basin until the early 1990s before dropping sharply. In recent years the concentrations decreased in the Bornholm Basin, but increased in the Gotland Basin. Deep water winter NH4 concentrations were insignificant in the Bornholm Basin, but increased in the Gotland Basin until the early 1990s. Afterwards values dropped sharply, increasing in the early 2000s. Some words with references on mechanisms?! 22 | ICES Working Group Report 2006 0.9 BB_surface 0.8 GB_surface 0.7 PO4 0.6 0.5 0.4 0.3 10 BB_bottom 8 GB_bottom 6 PO4 4 2 0 50 BB_bottom 40 GB_bottom 30 NH4 20 10 0 1975 1980 1985 1990 1995 2000 2005 Fig. CBS-3. Time-series on nutrient concentrations (µmol*l-1) in the Bornholm Basin (BB) and Gotland Basin (GB). Phytoplankton The development of the spring phytoplankton community was characterized by a strong increase in dinoflagellates compared to diatoms in the 1990s (Fig. CBS-4). This trend, observed in both the Bornholm and Gotland Basin was discussed to be a result of decreased silicate availability for diatoms after warm winters, which were prevailing in the 1990s (Wasmund et al. 1998). Chlorophyll a time-series do not show a pronounced increase during the 1990s, rather single outstanding peaks have been observed. An increase in summer dinoflagellate biomass during the 1990s is only observed in the Gotland Basin. Generally combined diatom and dinoflagellate biomass decreased until the late 1980s, increasing afterwards. Chorophyll a trends in both basins support a decrease in phytoplankton stocks in the 1980s, fluctuating on a higher level during the 1990s. ICES Working Group Report 2006 | 23 1800 10 1600 BB_spring 1400 8 dinoflagellates 1200 diatoms chlorophyll a 6 1000 800 4 600 400 2 200 0 0 18 3000 GB_spring 16 14 2500 12 Dinoflagellate and diatom biomass (mg*m-3) 2000 10 1500 8 Chlorophyll a (mg*m-3) 6 1000 4 500 2 0 0 1800 4.0 1600 BB_summer 3.5 1400 1200 3.0 1000 2.5 800 600 2.0 400 1.5 200 0 1.0 4.0 1600 GB_summer 1400 3.5 1200 3.0 1000 800 2.5 600 2.0 400 1.5 200 0 1.0 1975 1980 1985 1990 1995 2000 2005 Fig. CBS-4. Dinoflagellate and diatom biomass, as well chlorophyll a in the Bornholm Basin (BB) and Gotland Basin (GB). Zooplankton The dominating zooplankton species in the CBS are the copepods Acartia spp., Temora longicornis and Pseudocalanus acuspes (Fig. CBS-5a, b). During spring a clear shift has occurred from a dominance of P. acuspes until the end of the 1980s to Acartia spp. and T. longicornis afterwards. This shift has been explained by decreased salinity and high sprat predation pressure (P. acuspes) and increased temperature (Acartia spp., T. longicornis) (Möllmann and Köster 2002, Möllmann et al. 2003). During summer this shift is still visible, despite a higher variability. 24 | ICES Working Group Report 2006 25 1000 a) P. acuspes Synchaeta b) T. longicornis 20 800 Acartia spp. 15 600 10 400 Biomass (mg*m ) -3 5 200 0 0 40 1000 c) B. longispina maritima d) 800 30 600 20 400 10 200 0 0 1975 1980 1985 1990 1995 2000 20051975 1980 1985 1990 1995 2000 2005 Fig. CBS-5. Time-series on biomass of dominating zooplankton species in the Central Baltic Sea in spring (a) and summer (b, c, d). In summer, the zooplankton biomass is dominated by the rotifer Synchaeta sp. and the cladoceran Bosmina longispina marittima (Fig. CBS-5c). While the time-series of the latter shows two outstanding peaks, in the early 1980s and 1990s, the former diplayed only one in the early 1990s. Fish and fisheries Landings of the commercially important fish species in the Baltic Sea are dominated by cod (Gadus morhua), sprat (Sprattus sprattus) and herring (Clupea harengus) (Fig. CBS-6). While during the 1980s cod and sprat constituted the largest part of the commercial catches, since then sprat is the commercially most important species. 600 herring 500 sprat cod Landings (1000 t) 400 300 200 100 0 1975 1980 1985 1990 1995 2000 2005 Fig. CBS-6. Landings of cod, sprat and herring in the Baltic Sea. ICES Working Group Report 2006 | 25 The decrease in landings of cod and herring since the late 1980s was mainly due to a decline of the stock biomasses of these species (Fig. CBS-7). The cod stock collapsed due to climate- induced recruitment failure and a continuously high fishing pressure (Köster et al. 2005), while herring decreased mainly due to reduced growth (Möllmann et al. 2005), but also lower recruitment. In contrast the sprat stock increased to record levels during the 1990s being a result of climate-induced recruitment success and lower predation pressure by cod (Köster et al. 2003, MacKenzie and Köster 2004). The only locally important stock of flounder (Plathychtis flesus) displayed an undulating development with peak SSB in the early 1980s, 1990s as well in the present decade. These peaks are clearly associated with improved reproductive success. SSB (t) R (n*10 ) -6 WECA (kg) 800 1000 2.4 600 800 2.2 COD 600 2.0 400 400 1.8 200 200 1.6 0 0 2000 3e+5 0.018 3e+5 0.016 1500 SPRAT 2e+5 0.014 1000 2e+5 0.012 1e+5 500 0.010 5e+4 0 0 0.008 2000 40000 0.07 HERRING 1500 30000 0.06 1000 20000 0.05 0.04 500 10000 0.03 0 0 0.02 35 60 0.55 FLOUNDER 30 50 0.50 0.45 25 40 0.40 20 30 0.35 15 20 0.30 1975 1980 1985 1990 1995 2000 2005 1975 1980 1985 1990 1995 2000 2005 Fig. CBS-7. Spawning stock biomass (SSB), recruitment R and weight in the catch (WECA) of Baltic fish species. Cod and sprat exhibited clear density-dependent responses in individual weight (Fig. CBS-7). Since the 1990s individual cod weight was high in parallel to low stock size and vice versa for sprat. In contrast individual herring weight declined with stock size stabilizing since the mid 1990s, which is partly a result of the varying proportion of local populations with variable growth patterns (ACFM 2005). Further a real growth reduction since late 1980s was observed and discussed to be a result of competition with the large sprat stock (Casini et al. 2006, Möllmann et al. 2005). Further, for both pelagic fish species, but especially for herring, the decreased population size of the copepod Pseudocalanus acuspes, their main food source in spring, is an important factor for reduced individual growth (Möllmann et al. 2003, 2005, Rönkkonen et al. 2004). Individual weight of flounder increased since the late 1990s irrespective of stock size, which might be a result of reduced competition with cod for invertebrate food. 26 | ICES Working Group Report 2006 Integrated analysis An empirical overview of the temporal change of all CBS time-series is presented in Fig. CBS-8. Generally there is a trend from variables placed at the top of the plot having high values during the 1970s and early 1980s, to variables at the bottom displaying high values in the recent 15 years. The first group consists e.g. of variables related to cod, herring, Pseudocalanus acuspes, salinity and maximum ice extend, while the second group consists e.g. of temperature, sprat, flounder, Acartia spp. and Temora longicornis. An intermediate group is further visible with relativ high values in the 1970s/1980s, high values between 1988 and 1993, and again low values afterwards. This group consists mainly of indicator time-series related to nutrients and phytoplankton. The relative influence of the various time-series on the observed changes can be derived from the factor loadings (Fig. CBS-9) of the first 2 principal components PC1 and PC2 derived by PCA (Fig. CBS-10). These first two composite variables explain 22.8 and 12 % of the total variance. PC1 reflects mainly a temperature increase due to climatic processes (Alheit et al. 2005), while PC2 reflects changes in deep water salinity, bottom water nutrient and oxygen conditions. The common result of both trends is a regime shift, best visible in fish and zooplankton populations. High cod stocks in the late 1970s/early 1980s are replaced by a period of sprat dominance since the 1990s. The decrease in the cod stock is mainly caused by recruitment failue due to low salinity and oxygen conditions (Köster et al. 2005), while the higher water temperatures during the 1990s favoured sprat recruitment (MacKenzie and Köster 2004). Similarly the shift in the zooplankton from P. acuspes to Acartia spp. is caused by opposite hydrographic preferences (Möllmann et al. 2003). PC1 loadings additionally suggest that fishing mortality contributed to the dynamics of the cod stock, while this was less important for sprat. PC2 summarizes trends in the dynamics of the deep water in the Baltic basins, i.e. salinity, nutrient and oxygen conditions. The cumulative effects of the long lasting stagnation period since the late 1980s, with major inflows only in 1993 and 2003, lead to a gradual increase of NH4 and PO4 concentrations in the bottom water. High loading on PC2 for winter surface PO 4 in both the Bornholm and Gotland Basin indicates, that the bottom water nutrient concentrations have a pronounced effect on the surface layer PO 4 pool The loading for runoff is opposite, suggesting that the contribution from bottom water to surface nutrient pools is much larger than the river runoff nutrient loading. Relationships between phytoplankton related parameters – Secchi depth, chlorophyll a, biomass of phytoplankton groups – and the first two principal components are weak. Only spring dinoflagellate biomass in the Gotland Basin has a high loading on PC1. This could be a reflection of temperature induced species shifts in spring phytoplankton (Wasmund et al. 1998). Summer chlorophyll a as well as spring diatom and dinoflagellate biomass are reflected by PC2, but have opposite dynamics than the winter phosphate pool. The low correlation between phytoplankton and other parameters could also be caused by the shortness of the phytoplankton related time-series, which reflect only conditions during the 1980s and 1990s, and by the low temporal stability of phytoplankton indicators. While most other variables have a turnover time of weeks to years, phytoplankton turnover is on the order of days and therefore much more susceptible to fluctuations in e.g. weather conditions during sampling. ICES Working Group Report 2006 | 27 PC1 PC2 Variable 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 -5.1 0.3 CODSSB -5 -0.3 HERWC3 -4.9 0.3 S_GBSpr_0-10 -4.9 1.3 CODR2 -4.8 -0.1 CODland -4.7 -0.2 HERSSB -4.5 -0.9 HERland -4.4 0 S_BBSpr_0-10 -4.2 -1.6 Sync_Sum -4.1 -2.8 SPRWC3 -4 -0.4 S_GBSum_0-10 -4 0 HERR1 -3.7 1 Pseudo_Sum -2.8 -0 Pseudo_Spr -2.7 3 S_GBSpr_80-100 -2.5 -2.4 2.4 MaxIce 4 S_GBSum_80-100 Fig. CBS-8. Traffic-light plot of the development -2.2 -1.7 -0.6 PO4_GDWin -3.5 PO4_BBWinSur of the CBS ecosystem. Time-series are -1.7 -1.5 0.6 0.9 inflow SB_Secchi transformed to quintiles and sorted according to -1.5 1.5 Chla_BBSum PC1. For abbrevations see Annex3. -1.4 -1.7 Bosmina_Sum -1.2 NH4_GBWin_100-120 -2.2 -1.1 1.3 Cyano_BBSum -0.9 -3.4PO4_GBWin_0-10 -0.9 0.6 O2_BBWinBot -0.9 PO4_GBWin_200-220 -4.2 -0.8 -2.5NO3_GBWin_0-10 -0.7 -0.7 Temora_Sum -0.7 -1.8 NO3_BBWinSur -0.6 2.3 Bac_GBSpr -0.6 2.4 RunOff -0.5 NO3_GBWin_100-120 -1.1 -0.5 -4 SALcat -0.4 2.4 Dino_BBSum -0.4 2.3 REPVOL -0.4 -1.1 NO3_GDWin -0 2.8 FLOSSB 0.1 1.3 Coast1ShWi 0.1 -0.5 Bac_BBSum 0.1 NH4_GBWin_200-220 -4.4 0.1 1.4 NO3_BBWinBot 0.4 0.7 Cyano_GBSum 0.6 -2.1 NH4_BBWinBot 0.7 PO4_GBWin_100-120 -2.1 0.7 -1.6 Cyano_BBSpr 1 1.3 Chla_GBSpr 1.1 1.5 Chla_GBSum 1.1 -1.6 PO4_BBWinBot 1.3 2.4 Dino_GBSum 1.3 3.8 WBRCPUE 1.3 0 T_BBSum_0-10 1.4 -0 Coast1Rich 1.4 1 Bac_GBSum 1.5 4.3 SPR_F3-5 1.5 -2 T_BBSpr_0-10 1.7 0.3 CODWC3 1.7 -3.3 BSI 1.8 -0.9 Bac_BBSpr 1.8 2.4 S_BBSpr_70-90 1.9 2.6T_CoastSum_Sur 1.9 0.2 Chla_BBSpr 2.1 -0.9 ROACPUE 2.1 -4.1 11psu_GBAnn 2.2 0.3 Acartia_Sum 2.3 -2.3 Sync_Spr 2.4 -0.1 Cyano_GBSpr 2.5 -2.2 T_GBSpr_40-60 2.5 -2.4 CODF4-7 2.5 -1.9 T_GBSpr_0-10 2.6 -1.1 T_GBSum_0-10 2.7 -1 Temora_Spr 2.7 1.8 Dino_GBSpr 2.7 -1.7 T_BBSpr_40-60 2.9 0.1 FLOF4-6 3 0.8 SPRR1 3.1 2 FLOWC3 3.1 -1.4 RUFCPUE 3.2 -1.8T_GBSum_40-60 3.3 1.7 PERCPUE 3.5 -0.6 HER_F3-6 3.7 0.9 FLOR3 3.8 2.7 FLOland 3.8 0 Dino_BBSpr 4 -0.3 Acartia_Spr 4.2 -1.6 SALw3 4.7 2.3 SPRland 4.8 0.8 SPRSSB ICES Working Group Report 2006 | 28 0.4 0.2 PC-scores 0.0 -0.2 -0.4 1975 1980 1985 1990 1995 2000 2005 Year Fig. CBS- 9. Scores of principal components 1 (black circles) and 2 (white circles). The time-trajectories of PC1 and PC2 nicely summarize and demonstrate the change in states after 1987 and 1993, with transitional periods when both PCs are close together (Fig. CBS-9). The shifts are even more visible when plotting the time-scores of PC1 and 2 against each other (Fig. CBS-10). Clearly, 3 regimes are detectable and can be classified according to the mean hydrographic conditions in spring, e.g. in the Gotland Basin. The first regime (1974-87) was characterized by the lowest SST (5.0±0.5 ºC) and the highest deepwater salinity (10.2±0.5 psu). The intermediate period (1988-93) displayed the reverse conditions with on average the highest temperature (7.5±3.1 ºC) and lowest salinity (8.9±0.7 ºC). The last years of the investigated period exhibited intermediate values (6.9±2.0 ºC; 9.3.0±0.7 ºC). 0.4 1979 1977 2004 1980 1997 1978 1996 1995 0.2 1998 1974 2003 PC2 (12.0%) 1994 1976 1981 1975 1985 2002 1999 1987 2000 0.0 1982 2001 1983 1984 1986 1988 -0.2 1993 1991 1992 1989 -0.4 1990 -0.4 -0.2 0.0 0.2 0.4 PC1 (22.8%) Fig. CBS-10. Time scores of pricipal components 1 and 2 (PC1 and PC2); variance explained by PCs in brackets.. ICES Working Group Report 2006 | 29 In summary, the integrated analysis revealed major regime shifts in the ecosystem as has been reported for other areas, e.g. the Canadian Eastern Scotian Shelf (Choi et al. 2005), the U.S. continental shelf ecosystem (Link et al. 2002) and the North Sea (Beaugrand 2004). The major reasons for these regime shifts are changes in the temperature due to climate variability and change. For the CBS climate-driven physical conditions seem to be the major driver for ecosystem dynamics as well. In contrast to truly marine areas, the CBS experienced not only a regime shift during the late 1980s, but another one after 1993. The reason behind this is the additional importance of deep water salinity and oxygen conditions for the brackish Baltic Sea. The change in inflow frequency and related salinity and oxygen variability is thus a second factor affecting the structure and functioning of this ecosystem, in contrast to truly marine areas. ICES Working Group Report 2006 | 30 Gulf of Riga (GOR) Climate and temperature The development of the climate over the Baltic Sea area in the last 3 decades is displayed by the Baltic Sea Index, which well correlated with the Index of the North Atlantic Oscillation (NAO) (Lehmann et al. 2002). While during the 1970s and 1980s the index was mainly in a negative state, it was mainly positive afterwards (Fig. GOR-1). This change in sign of the index was associated with more frequent westerly winds, warmer winter and eventually a warmer climate over the area. This very well demonstrated by the convincing correlation fo the BSI with the air temperature (r=0.81). All time-series of water temperatures in the GOR reflect this warming during the 1990s. February (whole water column) May (0-20m) August (0-20m) 0.4 4 20 Air temperature (degC) 0.3 18 Water temperature (degC) 2 0.2 16 0.1 0 14 BSI 0.0 -2 6 -0.1 4 -4 2 -0.2 0 -0.3 -6 -2 1975 1980 1985 1990 1995 2000 1975 1980 1985 1990 1995 2000 Fig. GOR-1. Times-series of the Baltic Sea Index (BSI), as well as air and water temperatures. Nutrients Recordings of NO23 and PO4 were only available for the 1970s and since the late 1980s (Fig. GOR-2). Clearly both time-series show higher nutrient levels in the recent period compared to the ealier one. An intermediate minimum in nutrient concentrations was observed during the mid -1990s. 25 1.2 1.1 20 1.0 PO4 (µmol*l-1) NO23 (µmol*l-1) 15 0.9 10 0.8 0.7 5 NO23 PO4 0.6 0 0.5 1975 1980 1985 1990 1995 2000 Fig. GOR-2. Time-series on nutrient concentrations (µmol*l-1). ICES Working Group Report 2006 | 31 Phytoplankton Chlorophyll a concentration as an index for phytoplankton biomass displayed in spring an increase until the mid-1980s, dropping drastically afterwards (Fig. GOR-3). In the early 1990s there was a continuous increase despite pronounced fluctuations. The generally low summer chlorophyll a concentration increased steadily throughout the whole investigation period. 30 Spring 25 Summer Chlorophyll a (mg*m-3) 20 15 10 5 0 1975 1980 1985 1990 1995 2000 Fig. GOR-3. Time-series on spring and summer chlorophyll a concentrations. Zooplankton The development of the main zooplankton populations in spring (Fig. GOR-4) is characterized by a shift from a dominance of Limnocalanus grimaldii to Acartia spp. and Eurytemora affinis, which started in the late 1980s. In summer, cladocerans are dominating the zooplankton biomass, with however very low biomasses since the end of the 1990s. A decline in the summer biomass from the early 1980s to the early 1990s was also observed for E. affinis and L. grimaldii, while Acartia spp. biomass was rather stable. Spring Summer 350 350 Cladocerans 300 Acartia spp. 300 E. affinis 250 Biomass (mg*m-3) 250 Biomass (mg*m-3) L. grimaldii 200 200 150 150 100 100 50 50 0 0 1975 1980 1985 1990 1995 2000 1975 1980 1985 1990 1995 2000 Fig. GOR-4. Time-series on biomass of dominating zooplankton species in the GOR in spring and summer. Fish and fisheries Cod (Gadus morhua) was only caught in the GOR when the Eastern Baltic stock was large during the early 1980s (Fig. GOR-5). In contrast, herring (Clupea harengus) is the most 32 | ICES Working Group Report 2006 important commercial fish species in the GOR. Catches were stable until the early 1990s, drastically increasing afterwards. 50000 Herring 40000 Cod Landings (tonnes) 30000 20000 10000 0 1980 1985 1990 1995 2000 Fig. GOR-5. Cod and herring catches in the GOR. Fig. GOR-6 demonstrates the increase in herring catches to be due to an increase in stock biomass as a result of the high recruitment level during the 1990s. Mean individual weight of herring decreased in parallel to the stock biomass displaying a density-dependent process. However, in recent years individual weight increased despite the high stock levels, which might be a result of a changed food supply. Fishing mortality of this stock is relatively low and seems not to be the driving force for herring stock dynamics. 200 8000 180 7000 Biomass (1000tonnes) Recruitment (millions) 160 6000 140 5000 120 4000 100 3000 80 2000 60 1000 40 0 0.030 0.8 0.028 0.7 0.026 Mean weight (kg) 0.6 0.024 F ages 3-7 0.022 0.5 0.020 0.4 0.018 0.3 0.016 0.014 0.2 1975 1980 1985 1990 1995 2000 1975 1980 1985 1990 1995 2000 Fig. GOR-6. Time-series on herring biomass, recruitment (age 1), mean individual weight and fishing mortality (F). ICES Working Group Report 2006 | 33 SPRING PC1 PC2 Variable 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 -4.505 -2.3 TempMay20 -4.407 3.0 Herring -4.299 -0.6 Eurytemora -4.062 -0.8 Acartia -3.835 -2.7 AirTemp -3.835 -0.4 Cladocera -3.808 -2.8 TempFeb50 -3.718 -2.7 BSI -3.45 -2.6 Synchaeta -3.373 2.8 RecCur -3.12 1.7 PO4 -2.884 3.7 Catch -2.174 -2.2 Runoff -1.827 -2.5 NO23 -0.743 -3.4 DIN load previous 1.11 0.0 Chla 2.214 -0.2 Secchi 3.23 -1.3 Limnocalanus 3.539 0.0 F(3-7) 3.638 -2.8 HerWeight 4.27 -0.8 SalMay20 4.662 -2.7 Codcatch SUMMER PC1 PC2 Variable 1973 1974 1975 1976 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 -4.855 -1.2 Herring -4.195 -2.7 Catch -3.902 -1.3 RecCur -3.775 -0.3 PO4 -3.71 0.76 SChla -3.606 -2.2 Cercopagis -3.333 3.06 TMay20 -3.212 1.87 TAug20 -2.437 3.66 Tfeb -2.427 3.78 BSI -1.683 2.79 RunoffJanAug -0.682 3.64 DINloadJanAug -0.497 3.31 NO23 1.011 -2.5 Limnocalanus 1.477 2.36 Acartia 2.115 -1.5 SSecchi 2.858 3.3 Cladocera 3.099 -1.3 F(3-7) 3.997 0.63 Eurytemora 4.004 0.82 HerWeight 4.407 0.99 Rotatoria 4.47 -0.3 SalAug50 5.058 0.56 Codcatch 1st 2nd 3rd 4th 5th quintile Fig. GOR-7. Traffic-light plot of the development of the GOR ecosystem in spring and summer. Time-series are transformed to quintiles and sorted according to PC1. For abbrevations see Annex3. ICES Working Group Report 2006 | 34 Integrated analysis An empirical overview of the temporal change of all spring and summer GOR time-series is presented in Fig. GOR-7. Generally, there is a trend from variables placed at the top of the plot having low values until the late 1980s and high values afterwards, to variables at the bottom with the opposite trend. The first group consists in spring of hydroclimatic variables, the BSI and temperatures, as well as nutrient, zooplankton and herring time-series. The group of time-series with the opposite trend in spring consists of e.g. the copepod Limnocalanus grimaldii, cod catch and herring weight. In summer, a similar pattern was observed, although most of the zooplankton species (i.e. Acartia spp., Eurytemora affinis, cladocerans) were now found in the second group. The relative influence of the various time-series on the observed changes can be derived from the factor loadings (Fig. GOR-8) of the first 2 principal components PC1 and PC2 derived by PCA (Fig. GOR-9). PC1 explains most of the variance (37.6 and 36.0% in spring and summer, respectively) and reflects mainly a temperature increase due to climatic processes (Alheit et al. 2005) and the resulting positive effect on thermophilic species (e.g. herring and zooplankton). PC2 represents the opposite trend due to various biological mechanisms. An example is the opposite trend of the zooplankton species Acartia spp., Eurytemora affinis, cladocerans, which increase in spring, but decrease in summer. This shows that climatic processes act on the ecosystem mainly in spring (Dippner et al. 2000, Möllmann et al. 2003), but indicates also an increased predation pressure by the enlarged herring stock in summer (Kornilovs et al. 2004). Another internal mechanism is the decrease in herring weight, which may be due to density- dependent competition in the large herring stock. Runoff and nutrients are further related to the change in climatic conditions and increased since the late 1980s, while chlorophyll a as an index for the phytoplankton did not. This may be due to the quality of the sampling. The common result of both trends is a regime shift in the ecosystem caused by changed atmospheric forcing as seen in the CBS and other areas of the world ocean (see above). The time-trajectories of PC1 and PC2 summarize and demonstrate the change in states, which occurred in the GOR in contrast to the CBS between 1988 and 1989 (Fig. GOR-8). 0.6 Spring Summer 0.4 0.2 PC-scores 0.0 -0.2 -0.4 1975 1980 1985 1990 1995 2000 2005 1975 1980 1985 1990 1995 2000 2005 Fig.GOR- 8. Scores of principal components 1 (black circles) and 2 (white circles) for the spring and summer analyses. The shifts are even more visible when plotting the time-scores of PC1 and 2 against each other (Fig. GOR-9). Clearly, the shift in regime is detectable with a transitional period until 1991 in spring and 1993 in summer. ICES Working Group Report 2006 | 35 1996 Spring 2003 Summer 1990 0.4 0.4 1989 1983 1993 1991 1975 1997 0.2 0.2 1981 1995 2000 1992 2001 1994 1999 1976 1977 1986 PC2 (15.4%) 2004 PC2 (16.4%) 1987 1998 1985 1988 1982 2002 1992 2002 1998 1993 1974 1979 0.0 1984 0.0 2000 1994 1995 1973 1978 1991 1988 1982 1980 1980 1984 1973 1978 2004 1999 1985 1987 1981 1979 1986 2001 1975 1974 1976 1997 -0.2 -0.2 1996 1989 2003 1990 1983 -0.4 -0.4 -0.3 -0.2 -0.1 0.0 0.1 0.2 0.3 -0.4 -0.2 0.0 0.2 0.4 PC1 (37.6%) PC1 (36.0%) Fig. GOR-10. Time scores of principal components 1 and 2 (PC1 and PC2) for the spring and summer analyses; variance explained by PCs in brackets. References ACFM 2005. Report of the Baltic Fisheries Assessment Working Group (WGBFAS). ICES CM 2005/ACFM:19. Alheit, J., Möllmann, C., Dutz, J., Kornilovs, G., Löwe, P., Mohrholz, V. and Wasmund, N. 2005. Synchronous ecological regime shifts in the North and Central Baltic Sea in 1987- 88. ICES Journal of Marine Science 62: 1205-1215. Beaugrand, G. 2004. The North Sea regime shift: evidence, causes, mechanisms and consequences. Progress in Oceanography, 60: 245–262. Casini, M., Cardinale, M., and Hjelm, J. 2006. Inter-annual variation in herring, Clupea harengus, and sprat, Sprattus sprattus, condition in the central Baltic Sea: what gives the tune? Oikos 112: 638-650. Choi, J. S., Frank, K. T., Petrie, B. D., and Leggett, W. C. 2005. Integrated ecosystem assess- ment of a large marine ecosystem: a case study of the devolution of the Eastern Scotian Shelf, Canada. Oceanography and Marine Biology: an Annual Review, 43: 47–67. Dippner, J.W., Kornilovs, G., and Sidrevics, L. 2000. Long-term variability of mesozooplankton in the Central Baltic Sea. Journal of Marine Systems 25: 23-32. Hänninen, J., Vuorinen, I., and Hjelt, P. 2000. Climatic factors in the Atlantic control the oceanographic and ecological changes in the Baltic Sea. Limnology and Oceanography, 45: 703-710. Köster, F.W., Möllmann, C., Neuenfeldt, S., Vinther, M., St. John, M.A., Tomkiewicz, J., Voss, R., Hinrichsen, H.H., Kraus, G., and Schnack, D. 2003. Fish stock development in the Central Baltic Sea (1976-2000) in relation to variability in the physical environment. ICES Marine Science Symposia 219: 294-306. Köster, F.W., Möllmann, C., Hinrichsen, H.-H., Tomkiewicz, J., Wieland, K., Kraus, G., Voss, R., MacKenzie, B.R., Schnack, D., Makarchouk, A., Plikshs, M. and Beyer J.E. 2005. Baltic cod recruitment – the impact of climate and species interaction. ICES Journal of Marine Science 62: 1408-1425. Kornilovs, G., Möllmann, C., Sidrevics, L. and Berzins, V. 2004. Fish predation modified climate-induced long-term trends of mesozooplankton in a semi-enclosed coastal gulf. ICES C.M. 2004/L:13. Link, J.S., Brodziak, J.K.T., Edwards, S.F., Overholtz, W.J., Mountain, D., Jossi, J.W., Smith, T.D., and Fogarty, M.J. 2002. Marine ecosystem assessment in a fisheries management context. Canadian Journal of Fisheries and Aquatic Sciences 59: 1429–1440. 36 | ICES Working Group Report 2006 Lehmann, A., Krauss, W., and Hinrichsen, H.-H. 2002. Effects of remote and local atmospheric forcing on circulation and upwelling in the Baltic Sea. Tellus 54A: 299-316. MacKenzie, B.R., and Köster, F.W. 2004. Fish production and climate: sprat in the Baltic Sea. Ecology 85(3): 784-794. Matthäus, W., and Schinke, H. 1999. The influence of river runoff on deep water conditions of the Baltic Sea. Hydrobiologia 393: 1-10. Möllmann, C., and Köster, F.W. 2002. Population dynamics of calanoid copepods and the implications of their predation by clupeid fish in the Central Baltic Sea. Journal of Plankton Research, 24: 959-977. Möllmann, C., Köster, F.W., Kornilovs, G., and Sidrevics, L. 2003. Interannual variability in population dynamics of calanoid copepods in the Central Baltic Sea. ICES Marine Science Symposia 219: 220-230. Möllmann, C., Kornilovs, G., Fetter, M. and Köster, F. W. 2005. Climate, zooplankton and pelagic fish growth in the Central Baltic Sea. ICES Journal of Marine Science 62: 1270- 1280. Wasmund, N., Nausch, G., and Matthäus, W. 1998. Phytoplankton spring blooms in the southern Baltic Sea - spatio-temporal development and long-term trends. Journal of Plankton Research 20: 1099-1117. Rönkkönen, S., Ojaveer, E., Raid, T., and Viitasalo, M. 2004. Long-term changes in Baltic herring (Clupea harengus membras) growth in the Gulf of Finland. Canadian Journal of Fisheries Aquatic Sciences 61: 219–229 ICES Working Group Report 2006 | 37 Annex 5: Non- Paper Regional integrated assessment and the research organisation in the Baltic Sea within and outside ICES This document is a result of the joint meeting of SGMAB and SGBFFI in Riga, June 2005. While reviewing TORs f) – i) of SGMAB, dealing mainly with the future of the SG, the coordination with other SGs (especially those related to the BSRP) and contributions to the 2006 Theme Session on Regional Integrated Assessments, the need to re-organise the Baltic Sea research within ICES was discussed. The main arguments for re-organising the WG/SG- structure were: I. the need for advancing towards an Integrated Assessment (IA) of the Baltic Sea ecosystem similar as initiated for the North Sea (i.e. REGNS), as a basis for implementing the Ecosystem Approach to Fisheries Management (EAF); II. the need to react on the changing advisory requests after the replacement of IBFSC by bilateral negotiations between the EU and Russia. III. the need for an improvement of co-ordination of the WG/SG-work with other environmental organisations (e.g. HELCOM, EU Marine Strategy); IV. the need for an improvement of co-ordination of the WG/SG-work with the multitude of activities/research projects outside ICES (e.g. EU-funded projects BECAUSE, PROTECT) Presently the research in the Baltic Sea is conducted within a variety of fora ranging from ICES WGs and SGs, EU-funded research projects and WGs, to HELCOM WGs and projects. Between these different working frames, tasks and duties are either partly overlapping, although often conducted by the same institutions and/or scientists (ICES vs. STECF), or a tight connection is yet to be established (ICES vs. HELCOM). Even within the ICES Baltic community, activities are diversified in several sub-groups either overlapping in themes or being widely seperated, thus hampering an integrated view on the ecosystem. ICES presently faces the challenge to implement an EAF for which an IA of the ecosystem is needed as a basis. Consequently a regional ecosystem SG has been implemented North Sea (REGNS). In the Baltic Sea community a step towards this goal was made by implementing the GEF Baltic Sea Regional Project (BSRP). The project and its affiliated ICES SGs (SGBFFI, SGPROD, SGBEH and SGBEM) made considerable improvements in widening the perspective within the ICES Baltic community from rather “fish and physical environment - focused” to a more integrated view including lower trophic levels, ecosystem health issues and alternative approaches to ecosystem modelling. The project further initiated the development of indicator sets for assessing the state of the ecosystem and initiated progressive initiatives which should be templates for the future work, e.g. a combined ecosystem hydroacoustic open-sea survey. BSRP has further strengthened the communication and cooperation with HELCOM. Despite of these successes, the present approach of implementing an IA using BSRP as a vehicle, has several shortcomings: (i) the participation of non-funded “western” countries is low and decreasing which has the risk of separating communities, (ii) the different “discipline groups” work still largely seperated hampering an IA, and (iii) as the future funding of BSRP is unclear there is a risk to loose the first steps towards an IA when not implemented in the broader community. The above discussed challenges the present organisation of the work within the ICES Baltic science community. A new structure should consequently be developed providing the following: I. a platform for conducting an IA; 38 | ICES Working Group Report 2006 II. a concentration of the work in a reduced number of WGs/SGs; III. a better “outside communication/cooperation” with the EU-commission (i.e. STECF, JRC and EU-funded projects), as well as HELCOM and other international initiatives (e.g. BALTEX, BOOS, GLOBEC); IV. flexible tools to react on “hot topics” or “short-notice tasks”. In Fig. 1 a basic suggestion for a new ICES working group structure in the Baltic is sketched. This structure is suggested as a basic discussion frame which needs involvement of the different WG/SGs, the Baltic committee as well as the three ICES advisory committees. The structure is centered around two assessment groups, one for fish stocks and fisheries (FA WG) and one for the IA (IAWG). Both groups will be supported by observational data from an “Ecosystem Survey Group” (ESWG). This group will be central in implementing the IA and the EAF as it should develop in cooperation with HELCOM the present trawl and hydroacoustic surveys into ecosystem surveys which provide both “tuning” and “ecosystem” data. SG SG SG SG WK WK FA WG(s) IA WG WK WK WK WK ES WG Fig. 5.1. Suggestion of a new structure for the ICES Baltic Sea assessment and scientific activities. [SG-Study Group, WK-Workshop, FA-Fish stock assessment, IA-Integrated assessment, ES- Ecosystem survey] Both assessment groups will be supported by a limited number of SGs providing them with additional knowledge and information. On the “fish-side” this should include assessments and related issues, like multispecies modelling and age-determination. For the “ecosystem-side” this should include physical, chemical, lower trophic level (phyto- and zooplankton) and ecosystem modelling expertise, thus integrating the present BSRP-groups. A major task of these groups will be to facilitate the communication to scientific activities outside ICES, e.g. to EU-funded projects (from the “fish-side”) and to HELCOM (from the “ecosystem-side”). An important part of this suggested structure should be the increased use of workshops (WK). These should be vehicles to tackle “hot topics” or “short-notice tasks” coming up in various groups and should be solved in common, avoiding diversification and doubled work. ICES Working Group Report 2006 | 39 The most important change in this structure is the implementation of an IAWG. This will (i) assure the conservation, further development and the integration of the work done within BSRP in the broader scientific community, (ii) fullfill the request for an IA, which (iii) enables ICES to react on the new requirements in terms of advice which is due to the change in the management system of the Baltic and European waters. A second important issue will be the development of a common monitoring programme combining all available resources to effectively survey the whole ecosytem as a basis for an IA. ICES Working Group Report 2006 | 40 Annex 6: Existing Baltic Sea monitoring programmes HELCOM COMBINE The HELCOM COMBINE monitoring programme is targeted to assessing the effects of eutrophication on the Baltic ecosystem. It covers a list of mandatory core and voluntary main parameters, addressing hydrography, nutrients, and biota (Table 6.1). Table 6.1: Parameters included in the HELCOM COMBINE monitoring programme Hydrography Nutrients Biota phosphate, total temperature, salinity, phosphorus, nitrate chlorophyll a, phytoplankton oxygen, hydrogen + nitrite, (species composition, abundances, core sulphide, ammonium, total biomass), macrozoobenthos (species transparency nitrogen, composition, abundances, biomass) silicate zooplankton (species composition, abundances, biomass), primary production, phytobenthos current speed and main (composition and abundances), direction sinking rate of particulate matter, fluorescence profiles, fish (coastal areas) The station network used for COMBINE monitoring is dense, but monitoring intensity typically decreases from hydrographic parameters to nutrients and biota. Representative for stations with intensive sampling programme, Fig. 6.1 shows the distribution and sampling frequency of chlorophyll a under HELCOM COMBINE. It also has to be noted that the transect Helsinki – Travemünde monitored by Finland at by-weekly intervals is carried out by ships-of-opportunity measurements and covers only surface data. The HELCOM COMBINE monitoring programme is currently under revision in the HELCOM MON-PRO project. MON-PRO suggested structuring HELCOM COMBINE into trend and surveillance monitoring, operational monitoring and investigative monitoring. Trend and surveillance monitoring would be conducted annually in areas with acceptable eutrophication status, whereas operational monitoring would survey areas exceeding acceptable eutrophication status. Investigative monitoring is planned to improve the understand of eutrophication effects. The planned operational monitoring scheme includes 1 – 2 representative stations in each Baltic Sea sub-basin, where hydrographic parameters and nutrients as well as chlorophyll a/phytoplankton during the growth season would be measured at monthly intervals. The network of representative station will be supplemented by mapping surveys covering key ecosystem processes (winter nutrient concentrations, late summer oxygen minimum, spring and summer phytoplankton communities) together with annual (summer) surveys of phytobenthos and macrozoobenthos. Zooplankton is included into this proposed scheme as an optional parameter at representative stations and during a summer mapping survey (HELCOM MONAS 8/2005, Document 6.1/2). HELCOM COMBINE monitoring results are published in indicator fact sheets that are updated annually. Additionally, thematic and holistic assessments are produced at regular time intervals. ICES Working Group Report 2006 | 41 Figure 6.1. COMBINE stations with intensive sampling programme (HELCOM MON-PRO 3, Document 2.1.) ICES Working Group Report 2006 | 42 EU Water Framework Directive The EU Water Framework Directive requires regular assessment of the ecological status of coastal and transitional waters. Coastal waters are defined as marine waters within one nautical mile from the simplified coastline configuration, from which the breadth of territorial waters are measured. This definition includes many bays and inlets completely as coastal waters, even though their central areas might be further away from the coast then one nautical mile. Transitional waters are areas influenced by fresh water adjacent to river mouths. Classification of ecological status is based on mandatory biological quality elements, which are in turn supported by physico-chemical elements. Good ecological quality is reached, when both biological as well as physical-chemical elements reach the normative definitions for good quality. The water framework does not explicitly state a suite of parameters required for monitoring, but rather gives a list of quality elements, and a normative definition for the status classes (Table 6.2). Choice of indicators and monitoring parameters is left to national authorities. Each water body should be monitored at least once in the live time of a water management plan, covering the seasonality of all quality elements (surveillance monitoring), or, in the case of water bodies already at good status and under low pressure, the quality elements most sensitive to pressure (operational monitoring). Monitoring frequency most be chosen to minimize the effect of seasonality on assessment results and the WFD explicitly sets minimum monitoring frequency requirements. Further, the EU WFD demands to quantify confidence (power) and precision (relative confidence interval) of monitoring results, and to specify their target levels in the river basin management plans. To achieve reasonable confidence and precision of monitoring programs, in most cases the sampling frequency will have to be higher than the minimum frequency given in the WFD (CIS 2003). EU WFD monitoring networks have to be established in 2006 and reported to the EU Commission 22 March 2007 (http://europa.eu.int/comm/environment/water/water- framework/transposition.html). Assessment and consequently also monitoring under the WFD proceeds in 6 year cycles formalized in River Basin Management Plans. Water quality will be compared to the good water quality target in the years 2015, 2021, and 2027. For the first time, draft river basin management plans have to be prepared in 2008, and their final reporting deadline, including programs of measures to achieve good water quality, is 22 March 2010. ICES Working Group Report 2006 | 43 Table 6.2. Quality elements, normative definition of good ecological status and minimum monitoring frequency for coastal and transitional waters in the WFD. Minimum monitoring Quality element Quality element definition Normative definition of good status frequency Biological slight changes in composition and abundance compared to reference Phytoplankton composition, abundance and biomass conditions, no accelerated growth and no undesirable effects on biota, water 6 months and sediment, only slight increase and intensity of type-specific blooms slight changes in composition and abundance compared to reference composition and abundance of Other aquatic flora conditions, no accelerated growth and no undesirable effects to biota and 3 years macrophytes and angiosperms water composition and abundance of slight changes in composition and abundance compared to reference Benthic macro invertebrates 3 years benthic invertebrate fauna conditions, most type-specific sensitive taxa present abundance of disturbance-sensitive species slightly distorted due to Fish (only transitional composition and abundance of fish anthropogenic impacts on physico-chemical or hydromorphological quality 3 years waters) fauna elements Hydromorphylogical depth variation, structure and Morphological conditions substrate of the coastal bed, structure 6 years conditions consistent with the achievement of criteria for good status of the intertidal zone specified for biological quality elements direction of dominant currents, wave Tidal regime exposure, in transitional waters 6 years freshwater flow Physico-chemical Transparency 3 months Thermal conditions 3 months do not reach levels outside the range of ecosystem functioning and the Oxygenation 3 months achievement of good status specified for biological quality elements Salinity (only transitional) 3 months Nutrient status 3 months Pollution by all priority substances being discharged and all other priority substances 1 Specific pollutants not in excess of standards substances discharged in significant month, others 3 months quantities ICES Working Group Report 2006 | 44 EU commercial fish stock monitoring, fish stock assessment European Council regulation 1543/2000 sets the data collection requirements for the EU Common Fisheries Policy. For the Baltic Sea, the program requires monitoring of catches, including length and age composition, for the main commercial fish species (glass eel, yellow eel, silver eel, herring, cod, hake, blue whiting, Norway lobster, flounder, plaice, salmon, sea trout, sole, sprat), as well as collection of fishing effort and fishing capacity information. Priority fish surveys supplement the monitoring programme. Out of the species listed in the council regulation for Baltic Sea fish monitoring, only herring, cod, flounder, salmon, sea trout, and sprat are relevant for the Baltic Proper because of the low salinity. For these species the sampling program also requires collection of weight at age/length, maturity, and sex ratio data. The monitoring data further feed into fish stock assessment, which is based on age-structured modeling to reconstruct stock numbers in each age-class. While catch data drives the assessment models, scientific survey data are used for tuning. The EU sampling program identifies priority surveys for cod and sprat in the Baltic Proper, as well as for herring in Baltic Proper, Gulf of Riga, Gulf of Bothnia and Gulf of Finland (Table 6.3). The ICES Baltic International Fish Survey Working Group (WKBIFS) coordinates the surveys among the Baltic Sea countries. Table 6.3. Priority fisheries surveys in the Baltic Proper and Gulfs (herring surveys) Survey Survey type Target species Season First and fourth Cod and other BITS Trawl survey quarters (usually demersal species March and November) Third and fourth Herring acoustic Acoustic with Herring, sprat quarters (usually May survey control trawls and October) Acoustic with Second quarter Sprat acoustic survey Sprat control trawls (usually october) Fish stock assessment is organized with ICES working groups. The ICES Baltic Fisheries Assessment Working Group (WGBFAS) meets annually in April to assess the state of Baltic Sea fish stocks (cod, flounder, herring, sprat) and propose reference points and management measures. Salmon and sea trout assessment is produced by the ICES Baltic Salmon and Trout Assessment Working Group (WGBAST), which also meets annually in April. HELCOM coastal fish monitoring HELCOM coastal fish monitoring is presently carried out in 15 areas of the Baltic Sea, using multi-mesh gillnets and gillnet series (Fig. 6.2). The program is targeted to describe the long- term trends in coastal fish populations and to link them to natural and anthropogenic pressures. Monitoring is carried out in August and is mainly directed towards demersal and benthopelagic fish living in coastal areas during the warm season. Pelagic species (herring, smelt, sprat) are caught in significant numbers but with high random variability. The abundance of small-bodied fish (gobies, pipefishes, sand laces, sticklebacks) cannot be evaluated with the present monitoring methods. Coastal fish monitoring also includes measurements of temperature, salinity, wind speed and direction and transparency (HELCOM 2006). ICES Working Group Report 2006 | 45 Figure 6.2 HELCOM coastal fish monitoring stations (HELCOM 2006). Habitats and Birds directive, Baltic Sea Protected Areas Habitats and Birds directive require designation of protected areas (special areas of conservation - SAC, special protection areas – SPA, respectively) to establish favorable conservation status for species or habitats. Annexes of both directives prioritize species and habitats in need for protection. SAC and SPA form the network of Natura 2000 sites. A similar managed site network is formed by the Baltic Sea Protected Areas created according to a joint HELCOM/OSRPAR ministerial declaration (Bremen 2003). For Habitats and Birds directives, management plans and monitoring programs have to be established to ensure reaching or maintaining favorable conservation status of the species or habitat for which the site was designed. Potential links between the monitoring needs of habitats and birds directives and Baltic Sea integrated assessment are the food requirements of target species in SAC and SPA (macrozoobenthos, fish), disturbance of SAC and SPA species by fishing (bycatch of birds and mammals, removal of prey species), and the consequences of increasing target species stocks for their prey (e.g. conflicts between increasing seal stocks and fisheries in the Baltic). The Habitats Directive proposes a similar 6 year reporting cycle as the Water Framework Directive, with national reports to be submitted in 2007 and 2013. ICES Working Group Report 2006 | 46 Baltic Sea monitoring and reporting deadlines Table 6.4 lists presently known Baltic Sea monitoring, reporting and assessment deadlines. While EU fisheries data collection, fish stock assessment and also HELCOM indicator reports are produced on an annual basis, EU WFD and Habitats directive monitoring as well as HELCOM thematic and holistic assessments follow longer reporting cycles. Table 6.4. Important Baltic Sea monitoring, reporting and assessment deadlines Annual activities: EU fish monitoring & fish EU WFD and Habitats HELCOM thematic and Year stock assessment Directive holistic assessments HELCOM indicator reports HELCOM Thematic Assessments on eutrophication, biodiversity 2006 x and nature protection, hazardous substances, climate change Habitats Directive (reporting 2007 x on conservation status) 2008 x Water Framework Directive HELCOM EUTRO-PRO 2009 x (river basin management (eutrophication assessment plans, due March 22 2010) based on target levels HELCOM biodiversity 2010 x assessment (planned) 2011 x 2012 x Habitats Directive (reporting 2013 x on conservation status) 2014 x Water Framework Directive 2015 x (river basin management plans) References HELCOM, 2006. Assessment of Coastal Fish in the Baltic Sea. Balt. Sea Environ. Proc. No. 103 A CIS 2003. Common Implementation Strategy for the Water Framework Directive (2000/60/EC). Guidance Document No 7, Monitoring under the Water Framework Directive. ICES Working Group Report 2006 | 47 Annex 7: Extended Abstract The use of indicators for evaluation of trends in the Baltic Seppo Kaitala Dept. of Biological OceanographyFinnish Institute of Marine Research, Erik Palménin aukio 1 (P.O. Box 2), FIN-00561 Helsinki, Finlandtel. +358-9-61394417 fax +358-9- 323 2970E-mail:Seppo.Kaitala@fimr.fi Indices are a useful tool in integrated ecosystem analysis. Two examples (spring bloom index and cyanobacteria bloom index) are shown to develop ideas for the integrated assessment of the Baltic Sea. Phytoplankton spring bloom indexChlorophyll a concentration is a relative measure of phytoplankton biomass in the water. Since high nutrient concentrations increase phytoplankton growth and subsequently the intensity and frequency of blooms, chlorophyll a can be used as an indicator of the eutrophication in a sea basin. The intensity of the spring bloom reflects the scale of the nutrient reserves. The spring bloom species of diatoms and dinoflagellates consume most of the phosphorus and nitrogen nutrients that were built up in the water mass during the previous winter. The seven-day running average chlorophyll a curve in 2005 in the Western Gulf of Finland (green). Pink „area‟ illustrates the intensity index of the spring bloom, the spring bloom threshold is shown with a broken line. Also the peak and length of bloom are presented. ICES Working Group Report 2006 | 48 The spring bloom estimates for Arkona Basin (AB), the Northern Baltic Proper (NB) and the Western Gulf of Finland (GOF) from 1992 to 2005. Estimates: spring bloom intensity index, mean chl a during bloom, length of bloom, highest peak of the bloom and the starting day of the bloom. Years in which data have not covered the beginning of the bloom are marked with an asterisk. ICES Working Group Report 2006 | 49 Cyanobacteria bloom index Automated flow-through sampling system on merchant ships, sampling depth ca. 5 m. Samples for microscopical analyses of cyanobacteria are collected at eight of the 24 sampling points on the route across the Baltic Sea from Travemünde to Helsinki during the period from February/March to October/November. The indices are calculated by integrating the area under the local regression curve representing the occurrence of cyanobacteria (A. flos-aquae and N. spumigena) or toxic N. spumigena alone between days 100 and 300 of the particular year . Over the years the means of the indices are used as a reference point. Occurrence of A. flos-aquae (green) and N. spumigena (red) in year 2004, the rank abundance refers to the semiquantitative ranks obtained with the microscopy method of Algaline. The original samples are from automated ship of opportunity sampling between Helsinki and Travemünde (see the section metadata) and the curve was fitted with non-linear smoothing. On the x-axis is the running day (Julian day) of the year. The indices were obtained by integrating the area under the fitted curve from Julian day 100 to 300. For the cyanobacteria bloom index the area values for the two species were summed up. Cyanobacteria bloom index (the total bars consist of the two main nitrogen fixing bloom formers Aphanizomenon flos-aquae indicated with green color and Nodularia spumigena in red) and the mean (upper black broken line) of values, and the toxic Nodularia spumigena index with the mean (lower line) for the years 1997-2004. References Vivi Fleming, Seppo Kaitala 2005: Phytoplankton spring bloom biomass in the Gulf of Finland, Northern Baltic Proper and Arkona Basin in 2005. HELCOM Indicator fact sheet 2005. http://www.helcom.fi/environment2/ifs/ifs2005/en_GB/estimates/ Vivi Fleming, Seppo Kaitala 2005: Phytoplankton Spring Bloom Intensity Index for the Baltic Sea Estimated for the years 1992 to 2004 . Hydrobiologia. 554: 57 – 65. Seppo Kaitala, Maria Laamanen, Seija Hällfors and Heidi Hällfors 2005: Cyanobacteria bloom index. HELCOM Indicator fact sheet 2005. http://www.helcom.fi/environment2/ifs/ifs2005/en_GB/bloom_index/ ICES Working Group Report 2006 | 50 Annex 8: Abstract for I CES ASC Session P ICES CM 2006/Session P An integrated ecosystem assessment of the Central Baltic Sea and the Gulf of Riga Christian Möllmann, B. Müller-Karulis, R. Diekmann, J. Flinkman, G. Kornilovs, E. Lysiak-Pastuszak, J. Modin, M. Plikshs, Y. Walther, and N. Wasmund An integrated ecosystem assessment of two sub-systems of the Baltic Sea was conducted in the frame of the ICES “Workshop on Developing a Framework for an Integrated Assessment for the Baltic Sea [WKIAB]”. We present initial results of meta-analyses of oceanographic, nutrient, phyto- and zooplankton as well as fisheries data for the Central Baltic Sea (CBS) and the Gulf of Riga (GOR), the former comprising the highly stratified deep basins of the Baltic while the latter represents a shallow low saline coastal bay. Considering the period 1974 to 2004, 88 and 20 variables for the CBS and the GOR, respectively, were used in a Principal Component Analysis. Our integrated analyses demonstrate different regimes within the considered period, which were confirmed by chronological clustering. Major changes in ecosystem structure (regime shifts) were detected at the end of the 1980s, consistent with other areas of the world ocean. Our results further contribute to the understanding of the functioning of the ecosystems under anthropogenic and climatic pressure. Keywords: Central Baltic Sea, Chronological Clustering, Gulf of Riga, Integrated Ecosystem Assessment, Meta-analysis, Principal Component Analysis Contact author: Christian Möllmann: Danish Institute for Fisheries Research, Dept. of Marine Fisheries, Charlottenlund Castle, DK-2920 Charlottenlund, Denmark[tel: +45 3396 3458, fax: +45 3396 3333, e-mail:, firstname.lastname@example.org] ICES Working Group Report 2006 | 51 Annex 9: Re commendations RECOMMENDATION ACTION 1. To establish WGIAB (see below) 2. database at ICES DC 3.on sturcture of the Baltic committee expert groups 4.on developing a future monitoring strategy 5. 6. ICES Working Group Report 2006 | 52 Annex 10: The ICES/HELCOM Working Group on Integrated Assessments of the Baltic Sea [WGIAB] (Co-Chairs: Christian Möllmann, Denmark, Bärbel Müller-Karulis, Latvia. and Juha Flinkman, Finland, will meet in Malta from 10–14 March 2007 to: a) updating and further developing the Integrated Assessments (IA) for the Central Baltic Sea and the Gulf of Riga, and starting IAs for other subsystems of the Baltic Sea, i.e. the Gulf of Finland; b) cooperate with the HELCOM Biodiversity Assessments (BA), especially through developing an adaptive management framework (DPSIR); c) develop a common ICES and HELCOM indicator database and link the data to the HELCOM indicator fact sheets; d) prepare ecosystem overview and assessment documents as the basis for ecosystem-based management; e) provide an inventory on survey and monitoring activities by the different countries in 2006 for a sound planning of future IAs; f) review the various ecosystem modelling approaches available for the area and their importance and utility towards future IAs. WGIAB will report by DATE to the attention of the Baltic Committee. Supporting Information ICES Working Group Report 2006 | 53 PRIORITY: This Working Group is supposed to communicate and coordinate activities integrated ecosystem activities within and between ICES and HELCOM, specifically to update ecosystem overview assessments on a regular basis for different subareas, to conduct/contribute to HELCOM biodiversity and thematic assessments (e.g. pollution, eutrophication, impact of fisheries) and to use ecosystem modelling in the assessment work. Implenting this working group is a step towards implementing the ecosystem approach in the Baltic SCIENTIFIC The Working Group contributes to Actions 1.2, 1.7, 1.5, 1.7, 1.11, 1.12(1.12.6), 2.2, JUSTIFICATION AND 2.8, 2.9, 3.2, 3.3, 3.5, 3.6, 3.15, 4.2, 4.2, 4.11, 5.2, 5.3, 5.6, 7.3 of the ICES Action Plan. RELATION TO ACTION PLAN: Key to the implementation of an ecosystem approach to the management of marine resources and environmental quality is the development of an Integrated Assessment (IA) of the ecosystem. An IA considers the physical, chemical and biological environment – including all trophic levels and biological diversity - as well as socio- economic factors and treats fish and fisheries as an integral part of the environment. Contrary to e.g. the North Sea (REGNS) an IA for the Baltic ecosystem has not been developed, although a unique amount of data and expertise is available for the area. Individual components of a Baltic Sea ecosystem assessment have been prepared within ICES and HELCOM. ICES is routinely producing advice on the Baltic Sea commercial fish stocks. HELCOM assesses the effects of eutrophication on the Baltic ecosystem since in 2005 conducted an assessment of Baltic Sea eutrophication within the HELCOM EUTRO project. The Baltic Sea Regional Project provides a structure of coordination centres designed to address fish & fisheries, productivity, ecosystem health and socioeconomic modules of Baltic Sea management in accordance with the LME concept. The Workshop would start the process of establishing an IA for the Baltic Sea by developing a framework adapted to the ecosystem characteristics, human pressures, as well as the existing and emerging (e.g. EU Marine Strategy) assessment and management systems of the area. The first session of the Workshop will set up the scene: review existing approaches, methodologies, and legal framework(s), identify data needs and availability, select the appropriate site(s) for trial IA, and, depending on the identified information needs, initiate discussion on the optimisation of WG/SG/WK structure under BCC parentship and propose ToRs for these bodies. Trial IAs for selected sub-areas of the Baltic Sea will be performed to clarify the information needed and the assessment framework suitable for creating a holistic assessment. The trial IAs will provide supporting environmental information for fish stock assessment groups and contributions to the 2006 ASC “Theme Session on Regional Integrated Assessments”. A suite of biotic, abiotic and socio-economic metrics will be used with the goal to describe the impact of human activities and natural forcing (climate change) on the Baltic ecosystem and to derive potential reference points for ecosystem-based management. This involves multivariate statistical analyses of multiple time- series. The Workshop will build on the results and experiences of ICES EG related to the Baltic Sea, e.g. WGBFAS, WGBIFS, SGMAB, SGFFI, SGRPOD, SGEH, SGBEM, WGGIB, WGZE, WGPE, as well on the experience of relevant HELCOM projects (HELCOM EUTRO, HELCOM MON-PRO) and subgroups (HELCOM MONAS, HELCOM LAND). Building on the experiences gained from the trail IA, the Workshop will also suggest a future structure of working and study groups in the ICES Baltic Committee and will identify crucial terms of reference that have to be addressed within these groups to implement the ecosystem approach to Baltic Sea management. RESOURCE Assistance of the secretariat in maintaining and exchanging information and data to REQUIREMENTS: potential participants. PARTICIPANTS: The Working Groupp is expected to attract 25-30 participants, most of who would contribute data. Although many will be drawn from the ICES scientific community, success will be crucially dependent on the participation of scientists from outside ICES (especially HELCOM). SECRETARIAT None FACILITIES: FINANCIAL: None LINKAGES TO Relevant to the work of the ACE, ACME, and ACFM. ADVISORY COMMITTEES: LINKAGES TO BCC, WGBFAS, WGBAST, REGNS, all SG/WG related to Baltic Sea issues OTHER COMMITTEES OR GROUPS: LINKAGES TO Baltic Sea Regional Project (BSRP), HELCOM, BALTEX OTHER ORGANIZATIONS: SECRETARIAT 100% MARGINAL COST SHARE: ICES Working Group Report 2006 | 54 We suggest that each Expert Group collate and list their recommendations (if any) in a separate annex to the report. It has not always been clear to whom recommendations are addressed. Most often, we have seen that recommendations are addressed to: Another Expert Group under the Advisory or the Science Programme; The ICES Data Centre; Generally addressed to ICES; One or more members of the Expert Group itself. After submission of the report, the ICES Secretariat will follow up on the recommendations, which will also include communication of proposed terms of reference to other ICES Expert Group Chairs. The "Action" column is optional, but in some cases, it would be helpful for ICES if you would specify to whom the recommendation is addressed.