A PRELIMINARY ECOREGION CLASSIFI

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A PRELIMINARY ECOREGION CLASSIFI Powered By Docstoc
					Resource Directed Measures for Protection of Water Resources: River Ecosystems

R5: COMPREHENSIVE HABITAT INTEGRITY ASSESSMENT Senior Author: Editor: C.J. Kleynhans, Institute for Water Quality Studies, Department of Water Affairs and Forestry Heather MacKay, Department of Water Affairs and Forestry Lizette Guest, Guest Environmental Management 1.0 24 September 1999

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Appendix R5: Habitat Integrity Assessment for the Comprehensive Determination of the Ecological Reserve
Most of the information provided here is part of the Building Block Methodology Manual currently being prepaared under the auspices of the Water Research Commission of South Africa. See also Tharme and King (1998).

R5.1 Introduction
R5.1.1 The Role of River Habitat Integrity Assessment in River Structure, Functioning and Management
The ecological integrity of a river is defined as its ability to support and maintain a balanced, integrated composition of physico-chemical and habitat characteristics, as well as biotic components on a temporal and spatial scale that are comparable to the natural characteristics of ecosystems of the region. This definition is based on the concept of biological integrity that has been described as “the ability to support and maintain a balanced, integrated, adaptive community of organisms having a species composition, diversity and functional organisation comparable to that of natural habitat of the region” (Karr and Dudley 1981). Habitat integrity in this sense then refers to the maintenance of a balanced, integrated composition of physico-chemical and habitat characteristics on a temporal and spatial scale that are comparable to the characteristics of natural habitats of the region. Essentially, the habitat integrity status of a river will provide the template for a certain level of biotic integrity to be realised. In this sense the assessment of the habitat integrity of a river can be seen as a precursor of the assessment of biotic integrity. It follows that in this context habitat integrity and biotic integrity together constitutes ecological integrity (Kleynhans 1996).

R5.1.2 The Role of River Habitat Integrity Assessment in the Determination of the Comprehensive Ecological Reserve
Habitat integrity assessment for the comprehensive ecological reserve is based on low altitude helicopter surveys of the river. The purpose of habitat integrity is to provide a general indication of the current ecological condition of the river (or specific sections as required) as measured against a hypothetical natural situation. Together with inputs on the importance of the river, this information is then used in the determination of the ecological management class which is the objective in the setting of flow requirements for the river. The information on the habitat integrity of a river can also be used to indicate the general nature of ecological problems in the river and can make a contribution in the determination of the actual attainability of a specific desired ecological management class. The aerial survey also provides a considerable amount of information and insights on the characteristics of the river.

R5.2 Minimum and ideal data sets
The ideal data set for habitat integrity assessment would include the following:   Catchment information such as contained in the catchment study reports of DWAF. Up to date and reliable information on the hydrology in different ecologically different sections of the river (based on natural conditions and current development levels). This information will usually be provided by the hydrologist appointed for this function.

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Daily flow data for points in all ecologically different sections. This information will usually be provided by the hydrologist appointed for this function. Recent low altitude videography of the river from the source downstream to the sections being investigated. Representative water quality data for all the ecologically different sections of the river, especially relating to the requirements of biota. General water quality information can be found in the relevant water quality database of DWAF, or interpretations by a water quality specialist apointed for this purpose. Satelite imagery of the river's catchment. Comprehensive and recent survey information on the riparian zone and instream biota and their habitat requirements.

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The minimum data set for habitat integrity assessment would include the following:   General information on land use in the catchment. General information on the hydrology of the river, i.e. general information as to the extent of water abstraction and flow regulation. This information will usually be provided by the hydrologist appointed for this function. Videography or at least low level aerial photography for the section of the river under investigation. Some water quality information, or an informed judgment on the water quality as related to the requirements of aquatic biota. Some information on the aquatic biota, or at least an informed opinion on the attributes of the biota in the river section.

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R5.3. The sequence of necessary activities
The sequence of events described here are based on the understanding that the study area has been identified and the objectives specified.

Activity 1: Specifications for Aerial Survey By The Navigator
  Determine the length of river to be surveyed. 1:250 000 or 1:50 000 maps are suitable for this purpose. It is preferred, if an adequate budget is available, to capture the entire river from source to downstream end. However, depending on the nature of the future developments on the river and budgetary constraints, it may be appropriate to capture selected reaches of the river only. Specify the requirements regarding the helicopter and pilot experience: The helicopters best suited for river survey work are the Bell Jet Ranger or Hughes 500 as these are able to carry two to three passengers at a variety of altitudes with sufficient fuel for at least 2.5 hours of flying. Other important considerations are the need to negotiate tight turns with adequate stability for videographic purposes. Videography will be undertaken with the back door of the helicopter removed and the seats must be comfortable enough to work from for several hours. Suitable safety harnesses must be fitted (i.e. a “monkey-chain”). An intercom system must be standard equipment (all passengers and the pilot). The survey must be undertaken by the charter company as an organised charter operation as plain “hire and fly” operations do not offer adequate safety and insurance for the survey team during such surveys. Indemnity insurance must be carried by the charter company to adequately cover the lives of the survey crew. Usually cover is taken to an amount two million Rand per passenger. The pilot should have at least 2000 hours of helicopter experience and should be extensively experienced with low level flying operations.

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Quotations for helicopter costs must be obtained from the charter company up front. Logistics of the flight must then be determined carefully in order to establish the total costs of the survey. Apart from the costs of the survey itself, the ferry costs to and from the survey area must also be considered as these are often a large component of the total costs. Estimate the time required for the survey based on an airspeed of approximately 70 km/h. Estimate the ferry time required to get to the study area and back based on an airspeed of approximately 160 km/h. The flight logistics of the survey must be undertaken between the navigator and pilot several days prior to the survey to ensure that the videographic requirements are met, that suitable re-fueling points can be arranged and staff can be arranged for the provision of fuel at these points. Jet A1 fuel or paraffin is not available at all airfields and it is usually necessary, given the cost to ferry to nearby airfields, to make such arrangements. It is advisable that weather conditions are monitored several days before and that time contingencies are made for poor weather conditions should these occur on the day of the survey. If the survey is government funded, adequate time provision must be made prior to the survey to obtain information about the charter company which has the contract to undertake the work. If a company is not contracted in, or the company does not have the appropriate equipment for the survey, it will be necessary to have a suitable company appointed for the survey. This can take several weeks.

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Activity 2: Responsibilities of the Navigator during Planning of the Survey
  Obtain 1:250 000 or 1:50 000 (if available) scale topographic maps of the river section. Demarcate 5km long river length sectors on the maps to be used for the survey. Number these sectors starting from the point furthest upstream. It is often appropriate to use distinctive features such as road bridges to demarcate sector breaks as this will assist with navigation during the survey. Determine the co-ordinates of all 5km sector breaks and store these on a GPS. This step is vital if 1:50 000 maps of the survey are not available, particularly in rough terrain. Request the inputs of the group responsible for study site selection to make preliminary suggestions as to the general areas where sites are required. Contact the pilot and discuss with him details with regard to refueling points and times as well as overnight accommodation if necessary. Decide on responsibilities for ground support teams.

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Activity 3: Preparation of Video Equipment
Acquire the following:  A video camera. The minimum requirement is a Panasonic VHS analogue camera with a X 14 zoom and digital image stabiliser. If possible a video camera should be obtained which can display hours, minutes and seconds in order to synchronise with the GPS track log. If possible, also acquire a backup camera. A sealed 12 V compact battery pack with a cigarette lighter type socket, and a suitable cable to supply power from this battery pack to the camera. Such a battery pack should provide in excess of 5 hours of video time. Also acquire a spare battery pack and ensure that both are fully charged shortly before the survey. This battery pack (usually used for hunting lamps) is not a standard video camera accessory and can be obtained from dealers in camping equipment. A sufficient number of video camera cassettes, plus 2 - 3 spare cassettes. Cassettes with a recording capacity of one hour are preferred. A small clip-on microphone with a 2-3 m long extension cable that can be plugged into the video camera. The videographer must be completely comfortable and familiar with the operation and limitations of the video equipment.

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Activity 4: Pilot's Instructions
Prior to the flight, the videographer and navigator should discuss survey details with the pilot. This should include the following:   The altitude at which the survey will be conducted will vary depending on the width of the river. Usually, however, surveys are done at an altitude of 50 - 100 m. An explanation of the way in which the survey will be conducted. Usually the videographer is seated in the right hand back seat of the helicopter and the survey is done while flying downstream. To obtain a recording of details on both river banks, the pilot should fly along the left hand bank and also bias the front of the helicopter slightly towards the left to provide the videographer with the best possible view of the river. Surveys are usually done at an airspeed of approximately 70 km/h. The pilot should be aware that in certain cases he will be instructed to circle and/or hover the helicopter in order for the videographer to capture particular detail or to change video cassettes.

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Activity 5: Functions of the Navigator during the Survey
It is strongly recommended that a biologist with some previous experience of helicopter surveys and aerial navigation be used as navigator.    The navigator will use the prepared maps as well as GPS to navigate. The GPS tracklog should be managed at appropriate stages of the survey to ensure that this best corresponds with the video footage. It is required that he calls out the number of each sector when the helicopter moves into a sector over the intercom. The clip-on microphone from the video camera will be attached to the intercom microphone of the navigator. The navigator will be required to make observations on particular details which he observe, such as the presence of exotic plant species, disturbed areas (erosion), agriculture, etc. and this will be recorded directly onto the video cassette. The navigator should continuously check that the pilot is positioning the helicopter in a fashion, which provides the best possible view to the videographer. Particular attention should be paid to the height, the airspeed and the right hand bias of the helicopter. The navigator should be on the lookout for potential study sites. If such a site is found, the co-ordinates must be taken, the helicopter should circle and the videographer asked to record the details of the site. The navigator should also warn the pilot of any obstructions (i.e. cables) across the river. The navigator must ensure that regular breaks are taken. This will enhance concentration and prevent exhaustion. Usually a maximum stretch of 1 to 1.5 hours of continuous recording should be aimed for. The total video recording time per day should preferably not exceed 5 to 6 hours. After completion of the survey the navigator should provide a hardcopy of the tracklog and a GPS map of the flight path to the assessor. The tracklog should indicate the camera synchronised time of the survey along with co-ordinates of the flight path and the sector breaks. The tracklog may require some editing to remove unwanted track data and simplify the flight path map.

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Activity 6: Functions and Requirements of the Videographer during the Survey
It is strongly recommended that an aquatic ecologist with previous experience as to the operation of a video camera from a helicopter, be used as videographer.  Usually videography is done from the right hand back seat while flying downstream.

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The video recording is made by pointing the camera towards the front and slightly down. The time and date indicators of the camera should be turned on when recording. The camera's clock should be synchronized as closely as possible with that of the GPS. This will make it possible to locate particular points along the river on the video with some accuracy. Always check that the camera is actually recording. At the start of the survey or when a new cassette is inserted, a voice recording as to the name of the river should be made. When a new cassette is inserted, number the cassette that is removed and store it separately in a secure place. Care should be taken that both river banks and the channel itself are recorded on video. Instruct the pilot to position the helicopter correctly to make this possible and to limit including parts of the aircraft on the video. The videographer should continuously look up from the camera's viewfinder to determine if important river features (i.e. degraded areas, weirs, exotic vegetation, pumps, rapids, riffles, erosion dongas, etc.) are approaching. This will make it possible to zoom into such features as they are being passed. Zoom of 3 to 4 times were found to be suitable to use from a moving helicopter. Ensure that the digital image stabilizer is turned on when recording. It is useful to make recordings of the wider area along the river from time to time in order to get an indication of landscape features. If necessary the pilot should be requested to increase the altitude and to circle to get a proper perspective of the landscape. When cassettes or batteries are changed, the pilot should be requested to circle until the videographer is ready to continue with the recording. When the navigator indicates that the aircraft is moving into the next sector, the camera should be pointed to the roof of the helicopter and the sector number called out. This will also facilitate in rapidly finding the position of sectors on the cassette when rewinding or fast-forwarding on a video cassette recorder. If a clipon microphone is used, the navigator will record the sector number directly onto the cassette.

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Activity 7: Copying Camera Cassettes onto Video Recorder Cassettes
 It is strongly recommended that after completion of the survey the camera cassettes are copied onto video recorder cassettes, which should be clearly labeled "master copy". The video recorder cassettes are more convenient to work from (3 to 4 hour-long cassettes). The original camera cassettes should be clearly labeled and safely stored. A copy of the video should be provided for the group responsible for the selection of BBM sites.

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Activity 8: Assessment of Video Material
The navigation map and GPS track log are referred to when viewing the video material.   Usually the video recording is viewed at normal playback speed once without making any specific notes or reviewing any part. This is an uninterrupted familiarization run. The familiarization run is followed by another run during which the cassette is stopped and reviewed when necessary and notes on characteristics of each of the sectors taken. Notes on disturbances such as number of weirs, disturbed areas, land use (towns, informal settlement areas, agriculture, plantations), pumps, roads, bridges, erosion, exotic macrophytes, exotic riparian vegetation, trampled areas, etc. are taken, with some qualitative indication of the commonness or severity of modifications (Kleynhans 1996).

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During the second run the natural attributes of the river are also noted. This includes information on the geomorphological zonation of the river. Following the detailed viewing, it was found that playing the cassette at high speed at least two times and stopping and reviewing particular sectors or points provides a good perspective of riverine conditions. The last step in this activity is to make a shortened edited copy of the survey video recording that indicates the most important relevant aspects on the habitat integrity of the river. This copy will be shown during the specialist meeting and should preferably not be longer than 30 minutes.

Activity 9: River Zonation
Based on information available from topo-cadastral maps as well as the video, the river is categorized according to river zones following the basic approach of Wadeson and Rowntree (1994). The purpose of this is to categorise the river according to at least broad characteristics that can be related to the general riparian and instream habitats present. The approximate position of these zones is indicated on a map and the sectors present in each zone identified.

Activity 10: Ground Truthing
Following the aerial survey, it may be necessary or advisable that selected points along the river be visited to obtain specific information. This can include information on such aspects as indicated under Activity 11.

Activity 11: Rating of Habitat Integrity
Based on the information obtained from the video recording, as well as all available information as indicated in 2.0, the habitat integrity is assessed per sector and summarized per river zone. The methods used in the collation and interpretation of data and the rating and final assessment of the habitat integrity are elaborated on in Kleynhans (1996). In essence the procedure involves the separate assessment of the instream habitat integrity and the riparian zone habitat integrity according to a number of key criteria (Table 1). The observed or deduced condition of these criteria as compared to what it could have been under unperturbed conditions is surmised to indicate a change in the habitat integrity. A rating system (Table 2) based on differing weights (Table 3) for each criterion (according to its perceived importance in determining habitat integrity) is used to assess the total habitat integrity for the instream and riparian zone facets of the river. The final estimate of the criteria for the riparian zone and the water abstraction, flow modification, bed modification, channel modification, water quality and inundation criteria for the instream component, receive an additional weight if impacts on these were considered large, serious or critical. The sum of these ratings is used to classify the instream and riparian zone facets according to a descriptive integrity category (Table 4). An assessment and rating system has been developed in spreadsheet (QPRO for Windows or MS Excel) format to facilitate this assessment. A copy of this application is available from the authors.

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Table 1: Criteria used in the assessment of habitat integrity. CRITERION Water abstraction RELEVANCE Direct impact on habitat type, abundance and size. Also implicated in flow, bed, channel and water quality characteristics. Riparian vegetation may be influenced by a decrease in the supply of water. Consequence of abstraction or regulation by impoundments. Changes in temporal and spatial characteristics of flow can have an impact on habitat attributes such as an increase in duration of low flow season, resulting in low availability of certain habitat types or water at the start of the breeding, flowering or growing season. Regarded as the result of increased input of sediment from the catchment or a decrease in the ability of the river to transport sediment (Gordon et al., 1993). Indirect indications of sedimentation are stream bank and catchment erosion. Purposeful alteration of the stream bed, e.g. the removal of rapids for navigation (Hilden & Rapport, 1993) is also included. May be the result of a change in flow which may alter channel characteristics causing a change in marginal instream and riparian habitat. Purposeful channel modification to improve drainage is also included. Originates from point and diffuse point sources. Measured directly or agricultural activities, human settlements and industrial activities may indicate the likelihood of modification. Aggravated by a decrease in the volume of water during low or no flow conditions. Destruction of riffle, rapid and riparian zone habitat. Obstruction to the movement of aquatic fauna and influences water quality and the movement of sediments (Gordon et al., 1992). Alteration of habitat by obstruction of flow and may influence water quality. Dependent upon the species involved and scale of infestation. The disturbance of the stream bottom during feeding may influence the water quality and increase turbidity. Dependent upon the species involved and their abundance. A direct anthropogenic impact which may alter habitat structurally. Also a general indication of the misuse and mismanagement of the river. Impairment of the buffer the vegetation forms to the movement of sediment and other catchment runoff products into the river (Gordon et al., 1992). Refers to physical removal for farming, firewood and overgrazing. Includes both exotic and indigenous vegetation. Excludes natural vegetation due to vigorous growth, causing bank instability and decreasing the buffering function of the riparian zone. Allochtonous organic matter input will also be changed. Riparian zone habitat diversity is also reduced. Decrease in bank stability will cause sedimentation and possible collapse of the river bank resulting in a loss or modification of both instream and riparian habitats. Increased erosion can be the result of natural vegetation removal, overgrazing or exotic vegetation encroachment.

Flow modification

Bed modification

Channel modification

Water quality modification

Inundation

Exotic macrophytes Exotic aquatic fauna

Solid waste disposal Vegetation removal

Exotic vegetation encroachment

Bank erosion

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Table 2: Descriptive classes for the assessment of modifications to habitat integrity. IMPACT CATEGORY None Small Moderate Large DESCRIPTION No discernible impact, or the modification is located in such a way that it has no impact on habitat quality, diversity, size and variability. The modification is limited to very few localities and the impact on habitat quality, diversity, size and variability is also very small. The modifications are present at a small number of localities and the impact on habitat quality, diversity, size and variability is also limited. The modification is generally present with a clearly detrimental impact on habitat quality, diversity, size and variability. Large areas are, however, not influenced. The modification is frequently present and the habitat quality, diversity, size and variability in almost the whole of the defined area is affected. Only small areas are not influenced. The modification is present overall with a high intensity. The habitat quality, diversity, size and variability in almost the whole of the defined section are influenced detrimentally. SCORE 0 1-5 6-10 11-15

Serious

16-20

Critical

21-25

Table 3: Weights of criteria used for the assessment of instream and riparian zone habitat integrity. INSTREAM CRITERIA Water abstraction Flow modification Bed modification Channel modification Water quality Inundation Exotic macrophytes Exotic fauna Solid waste disposal TOTAL WEIGHT 14 13 13 13 14 10 9 8 6 100 TOTAL 100 RIPARIAN ZONE CRITERIA Indigenous vegetation removal Exotic vegetation encroachment Bank erosion Channel modification Water abstraction Inundation Flow modification Water quality WEIGHT 13 12 14 12 13 11 12 13

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Table 4: Habitat integrity assessment categories. CATEGORY DESCRIPTION SCORE (PERCENT OF TOTAL) 100 80-99

A B

Unmodified, natural. Largely natural with few modifications. A small change in natural habitats and biota may have taken place but the ecosystem functions are essentially unchanged. Moderately modified. A loss and change of natural habitat and biota have occurred but the basic ecosystem functions are still predominantly unchanged. Largely modified. A large loss of natural habitat, biota and basic ecosystem functions have occurred. The loss of natural habitat, biota and basic ecosystem functions are extensive. Modifications have reached a critical level and the lotic system has been modified completely with an almost complete loss of natural habitat and biota. In the worst instances the basic ecosystem functions have been destroyed and the changes are irreversible.

C

60-79

D E F

40-59 20-39 0-19

R5.4 Summary of what to include in the habitat integrity assessment documentation and how this is used during the specialist meeting
The documentation for the specialist meeting should include concise information on the habitat integrity as well as conclusions regarding the main reasons for the habitat integrity status of the river. Apart from the normal structure of the document, the following should form the body of the starter document:   A map indicating sectors, zones and all relevant detail. Graphs indicating changes in the hydrology of the river at the points for which data is available. Aspects of particular importance can often be found in flow duration curves (daily or monthly) as provided by the hydrologist involved with the study. Relevant water quality data and information. This can be tabulated if necessary. Tables for respectively the riparian zone and the instream component indicating the main modifiers per sector or zone. Graphs indicating the ratings for the different modifiers per sector or zone for respectively the riparian zone and the instream component (cf. Table 1). These graphs are generated automatically by the spreadsheet application. Graphs indicating the integrity class assessment for respectively the riparian zone and instream components (cf. Table 4) per sector or per zone. These graphs are generated automatically by the spreadsheet application.

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The purpose of this document and the information it contains, is to enable participants in the specialist meeting to form an idea of the condition of the river and to be informed as to the main reasons for the river being in a particular ecological state. Eventually this information will be used in the process of deciding on an attainable ecological management class for the river.

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R5.5 Roles and responsibilities at the specialist workshop
At the specialist meeting a presentation of the habitat integrity status of the river should be given. With the understanding that the participants have read the starter document, only the main points should be indicated and maps and graphs used to aid in this process. It is important that the edited version (indicating the most relevant and important aspects) of the video recording be shown to the specialist meeting participants. The presenter of the habitat integrity status report should ensure that sufficient relevant comment and explanation is given while showing this video.

R5.6 Roles and responsibilities after the specialist workshop
It must be emphasized that the habitat integrity assessment is often done without having access to the information emanating from other work being done for the specialist workshop. This includes information on river geomorphology and classification (i.e., zonation) and water quality assessment. Information on hydrology is usually provided during the assessment of the habitat integrity, but additional information on this and other aspects may also only become available during the workshop. This additional information may have an influence on the ratings of individual impacts and the habitat integrity assessment classes, and will have to be considered in context to determine if the habitat integrity assessment needs to be adapted for inclusion in the final workshop proceedings documentation.

R5.7 Example of terms of reference
The terms of reference for habitat integrity assessment should contain the following directives:    The section of the river being investigated should be indicated accurately. This also includes parts of the river upstream and outside the direct area of impact of any planned development if necessary. Specific indications should be given that the survey should be based on a low altitude helicopter survey (50 - 100 m altitude), but that ground truthing may be required at selected points. The products required will be:

Topo-cadastral maps (1:250 000 and 1:50 000 if available) of the study area. The river section being investigated must be numbered according to 5 km long sectors on these maps and used for navigation. The coordinates of both upstream and downstream points of the 5 km sectors should be determined. Classification of the river in geomorphological zones is required and these zones should be indicated on the maps and documentation. The survey should provide information and detail on possible study sites. Videography as well as still photography of such sites are required. The coordinates of such sites as well as their accessibility must be recorded and reported on seperately. A continuous low altitude video recording of the river must be produced. This video should include both the instream and riparian aspects of the river and must be referable to the navigation maps. The numbering of 5 km river sectors should be voice recorded on the video cassette. A specified number of copies of the orginal video recording should be made. The instream and riparian zone habitat integrity of the river must be assessed for each sector and river zone and reported according to approved procedures and methodologies. Apart from information originating from the river survey, all other available information sources must be consulted for the assessment of the habitat integrity.  The results of the survey and the habitat integrity assessment must be reported on during the specialist meeting. This must include references to an edited (30 minute) video recording of the survey.

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It may be required that the habitat integrity assessment report be adapted based on information that comes to light during the specialist meeting.

R5.8 Minimum and optimum specialist training
 It is strongly recommended that an aquatic ecologist with some previous experience of helicopter surveys and aerial navigation be used as navigator. The minimum requirement is a person with some aerial navigation experience. It is strongly recommended that an aquatic ecologist with previous experience as to the operation of a video camera from a helicopter be used as videographer. The minimum requirement is an experienced videographer who has been fully briefed on what is expected of him, or an ecologist with little experience of videography but who has been fully briefed on what is expected of him. The videographer should feel comfortable to record for extended periods of time from an open helicopter door. The person who eventually assesses the habitat integrity should be an aquatic ecologist, preferably with experience of the assessment methodology and knowledge of the river. The ideal situation is where this experienced ecologist was the videographer or navigator during the survey. The minimum requirement is an aquatic ecologist with some access to the advice of another aquatic ecologist who is experienced in the assessment methodology. In such a situation it is also essential that the aquatic ecologist discuss particulars of the river with the navigator or videographer.

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R5.9 Potential pitfalls
   Helicopter surveys are expensive and it is important that backup equipment such as a camera, extra videocassettes and a battery be available for emergencies. Bad weather conditions can make aerial surveys impossible. It is important to obtain medium term weather forecasts prior to the start of the survey and make decisions based on this information. If at all possible, it is recommended that surveys only be done during the dry season. Apart from bad weather conditions during the rain season, the riparian vegetation may be so dense during this time and the flow so high that only limited observations may be possible.

R5.10 Further developments
 It can be expected that technological developments will improve the quality of video recordings considerably (i.e. digital video cameras, GPS links to the video camera and the storage of video recordings in CD-ROM or DVD format). In addition, low level aerial photography, satellite imagery, etc. can be expected to be applied more extensively in the future. The habitat integrity assessment methodology should be improved. Habitat integrity assessment is based on a simplified, fundamental understanding of the relationship between certain environmental modifications and aquatic habitat changes. As this understanding and insight improves it will be possible to establish clearer links between environmental changes and habitat modification. The development of indices to assess the impacts of changes in hydrology, water quality, bed characteristics, etc. is envisaged. Such subindices will have to be integrated into a total habitat integrity assessment index.

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R5.11 Monitoring
 It is expected that monitoring of habitat integrity based on aerial surveys will only be undertaken when a river has been identified for major water resource development or when some extensive degradation of the river is suspected. In conjunction with additional information sources, this will represent the current baseline habitat integrity for the river. However, once rivers have been prioritised based on ecological R5/12

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importance and sensitivity and development pressure, it is envisaged that they will be surveyed more regularly.  After the ecological reserve has been determined, monitoring (biological, flow, habitat, water quality, etc.) will take place to assess if the ecological management class for the river is being achieved. Habitat integrity assessment can be part of this monitoring or can occur in response to particular issues arising from monitoring. Generally the habitat integrity assessment must be seen as indicating changes on a mesoscale (spatially and temporally) compared to monitoring of the chemical, physical and biological aspects that will in comparison tend towards the microscale. The response of the riparian zone and the instream component due to a particular flow specification, can therefore often be expected to be relatively slow and may only be evident after a number of years. Apart from its role in the determination process of the ecological Reserve, habitat integrity surveys also form part of the River Health Program. Within this program it can be envisaged that habitat integrity assessments may under certain circumstances be repeated depending on biomonitoring results.

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R5.12 Conclusion
There is considerable room for the improvement of the data gathering techniques as well as the habitat integrity assessment methology. However, despite its limitations the habitat integrity assessment forms an important part of the ecological Reserve determination process, in the provision of information on the ecological condition of the river.

References
Gordon, N.D., T.A. McMahon & B.L. Finlayson.1992. Stream hydrology: An introduction for ecologists. John Wiley & Sons, Chichester, New York, Brisbane Toronto, Singapore. 529 pp. Karr, J.R. & D.R. Dudley. 1981. Ecological perspective on water quality goals. Environ. Manage. 5:55-68. Kleynhans, C.J. 1996. A qualitative procedure for the assessment of the habitat integrity status of the Luvuvhu River (Limpopo system, South Africa). Journal of Aquatic Ecosystem Health, 5: 41-54. Tharme RE and JM King (1998). Development of the Building Block Methodology for Instream Flow Requirements and Supporting Research on the Effects of Different Magnitude Flows on Riverine Ecosystems. Water Research Commission Report Number 576/1/98, Pretoria, 452pp and Appendices. Wadeson, R.A. & K.M. Rowntree. 1994. A hierarchical geomorphological model for the classification of South African river systems. In: Uys M.C. (Ed.) Classification of rivers, environmental health indicators. Proceedings of a joint South African/Australian workshop. February 7-14 1994, Cape Town, South Africa. Water Research Commission Report No. TT 63/94.

Department of Water Affairs and Forestry, South Africa Version 1.0: 24September 1999

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