ECASA WP 2 Friday, 17 December 2004
Annotated sheet for indicators1
related to the impact of aquaculture on the environment
1- Name of indicator, authors
Phytoplankton chlorophyll a
2- Computation : Formulae, or model output.
Whenever possible, please use a range of 0-100. Ranking the results in few classes (five?) is
another option for qualitative indicators.
Maximum and mean chlorophyll a concentrations during the growing season should
remain below elevated levels, defined as concentrations > 50% above the spatial
(offshore) and/or historical background concentration.
3- List of data / parameters required for computation.
Chlorophyll a concentrations time series for both stations (within the study site and
control outside the study site). Long time series (over a several years) are preferred
but shorter time series would be acceptable.
4- Description of scientific meaning, references
The primary biological response to nutrient enrichment in aquatic environments,
given suitable environmental conditions (such as light availability and water
temperatures), is the growth of phytoplankton and higher plants. Assessment of the
magnitude of the response should ideally be based on estimates of primary
production rates of the different plant groups. For numerous reasons (including
limited financial and human resources), measurements of primary production are not
included in routine surveys for monitoring water quality in coastal environments. For
phytoplankton, it is assumed that biomass may be used as a proxy for net production.
Concentrations of chlorophyll a in water samples are used as an index of
Maximum and mean chlorophyll a concentrations during the growing season (March
to September) are the basic parameters required to assess chlorophyll a as an
estimate of plant biomass. In temperate waters, maximum concentrations are
expected to occur in the early part of the year, during the spring bloom. The timing of
the spring bloom is predictable in most areas.
Please return these sheets to the WP 2 leader, BEFORE end of March 2005.
Painting, S. (2004). Assessing the suitability of OSPAR EcoQOs vs. ICES criteria.
Report to DEFRA.
OSPAR Comprehensive procedure.
5- Range of validity; please provide a description of the field of validity for the
indicator, its limits, endpoints. Careful explanations should be given in a table
about the correspondence between the computed values and the impact (from
positive effect, no impact , moderate impact, high impact, unacceptable impact).
Range of valid ity : from 0 to 100%
No impact 0%
Low impact 1 to 4%
Moderate impact 5 to 19%
High impact 20 to 49%
Unacceptable impact > 50%
6 -Type of aquaculture on which this indicator applies
-Open sea aquaculture (limited)
-Intertidal, extensive aquaculture
-Earthen pond aquaculture located on the shoreline
6- Relevant environments for this indicator
Open sea (limited)
Sheltered areas (bays, fjord, estuaries)
Land-based marine aquaculture at the immediate vicinity of the shoreline
8- Quotation. We will need to select the most appropriate indicators to be proposed for
EIA and site selection. Please suggest a quotation for this indicator for the following
criteria (from A, perfectly adequate, to E, not relevant), to help evaluating the
indicator within WP 4. Additional comments are welcome.
Direct relevance to objectives : The indicator selection must be closely linked to the
requirements of the EU: Use for environmental impact assessment and site selection.
This aspect should be detailed. - A
Clarity in design : It is important that the selected indicators are defined clearly in
order to avoid confusion in their development or interpretation. - A
Realistic collection or development costs : Indicators must be practical and realistic,
and their cost of collection and development therefore need to be considered. This
may lead to trade-offs between the information content of various indicators and the
cost of collecting them. - B
High quality and reliability : Indicators, and the information they provide, are only
as good as the data from which they are derived. - A
Appropriate spatial and temporal scale : Careful thought should be given to the
appropriate spatial and temporal scale of indicators. - B
Obvious significance : The meaning and usefulness of the indicator should easily be
understood by stakeholders. They would preferably use the levels of dissolved oxygen,
rather of sulphide concentrations. - A
9- Data and models related to this indicator, available for use by WP 4. Please list the
data and models output available at local, national or regional scales for use by ECASA.
They may not correspond to the more theoretical list asked for in §3.
CSTT model (Paul Tett)
FJORDENV model (A. Stigebrandt)
Assimilative Capacity model (C. Laurent)
Mussel model (T. Hawkins)
TRIMODENA (J. Mader)
ASSETS (J. Ferreira)
10- Suggestions for use by WP 5. Give examples of indicators/aquaculture/environments
which can be field-tested during the course of WP 5.
The proposed indicator could be tested in Loch Creran (Scotland) by measuring its
present value, in the presence of a fish farm, and comparing this with historic data
taken during the 1970s, before the farm was in place.
This document is intended to be used for internal work on ECASA workpackage. The final
indicator sheet may include a format somewhat different. Please suggest any improvement for
both the content and the form of this document.