INTEGRATION OF FRESHWATER BIODIVERSITY IN AFRICA’S DEVELOPMENT PROCESS:

INFORMATION COLLECTION AND DEMONSTRATION SITES

PRELIMINARY PLAN

For the monitoring of FRESHWATER BIODIVERSITY

IN THE GAMBIA BASIN

Wetlands International Africa Rue 111, Zone B, Villa № 39B, BP.25581 DAKAR-FANN. SENEGAL wetlands@orange.sn

Preliminary Plan for Freshwater Biodiversity Monitoring in the Gambia river basin Page 1

December 2009 WORKING GROUP 1. Coordination team

AGBLONON Gabin NIANE Mamadou NIANG-DIOP Fatimata WADE Mawade

2. Consultants

Dr. NDIAYE Abdoulaye Dr. NIANG-DIOP Fatimata Dr. Niasse Farokh Dr. SARR Alassane Dr. SEGA Moussa

FIGURE 1: GAMBIA BASIN

Preliminary Plan for Freshwater Biodiversity Monitoring in the Gambia river basin Page 2 TABLE OF CONTENT 2. OBJECTIVE ...... 6 3. METHODOLOGY ...... 6 3.1. Species and key habitats concepts ...... 6 3.2. Site selection criteria ...... 7 3.3. Species selection criteria ...... 7 4. PROPOSED SITES AND SPECIES TO BE MONITORED ...... 8 4.1. Proposed sites to be monitored ...... 8 4.2. Proposed species to be monitored ...... 11 4.2.1. The crabs ...... 11 4.2.2. The mollusks ...... 12 4.2.4. Birds ...... 13 4.2.6. Fish ...... 13 5. DATA COLLECTION ...... 14 5.1. Crabs ...... 14 5.2. Mollusks ...... 15 5.3. Odonata ...... 15 5.4. Birds ...... 18 5.5. Plants ...... 19 5.6. Fish ...... 21 6. MONITORING INDICATORS ...... 21 6.1. Crab monitoring indicators ...... 22 6.2. Mollusk monitoring indicators ...... 22 6.3. Odonata monitoring indicators ...... 24 3.4. Bird monitoring indicators ...... 24 6.5. Plant monitoring indicators ...... 25 6.6. Fish monitoring indicators ...... 25 6.7. Fish monitoring indicators ...... 26 7. MONITORING FREQUENCY ...... 29 7.1. Crabs ...... 29 7.2. Mollusks ...... 29 7.3. Odonata ...... 29 7.4. Birds ...... 29 7.5. Plants ...... 29 7.6. Fish ...... 30 8. ACTORS AND PARTNERS INVOLVED IN THE MONITORING ...... 30 PARTNERS ...... 30

Preliminary Plan for Freshwater Biodiversity Monitoring in the Gambia river basin Page 3 Organization for the development of the gambia river (OMVG) ...... 30 Wetlands International...... 30 Gambia ...... 30 Guinea ...... 31 Ministry of Environment ...... 31 Universities and research institutions ...... 31 Local Collectivities ...... 31 Guinea-Bissau ...... 31 Ministry of Environment ...... 31 Universities and research institutions ...... 31 Senegal ...... 31 Universities and research institutions ...... 31 Local Collectivities ...... 31 REFERENCE/BIBLIOGRAPHY ...... 32 ANNEXES ...... 37 Table of Figures:

Figure 1: Gambia Basin ...... 2 Figure 2: Monitoring sites within Senegal and Guinean Gambia Basin ...... 9 Figure 3: Monitonring sites within Gambia Gambian Basin ...... 10 Figure 4: Monitoring sites within Guinean Gambia Basin ...... 11 Figure 5: Freshwater crabs within the Gambia Basin ...... 12 Figure 6: Freshwater odonate within the Gambia Basin ...... 13 Figure 7: Freshwater fish within the Gambia Basin ...... 14

Preliminary Plan for Freshwater Biodiversity Monitoring in the Gambia river basin Page 4 1. RATIONALE AND BACKGROUND

Supported by Wetlands International, IUCN implemented a program entitled, "Integration of freshwater biodiversity in Africa’s development process: information collection and demonstration site.” The program’s overall objective is to assess the conservation status of freshwater species across the African continent and ensure effective consideration and use of data related to this biodiversity, both in decision making and implementation of development activities in Africa. This program has two phases. The first phase focuses on the collection of information to assess the conservation status of selected taxa on IUCN’s private list. The second phase is linked to the implementation of a case study on The Gambia River basin demonstration site.

This program enables water resources managers and environmental planners to integrate information on freshwater biodiversity in the development process. The specific objective is to ensure that environmental planning for the development of water resources throughout Africa is based on the integration of reliable data, on the status, distribution and ecological conditions of freshwater biodiversity for priority taxonomic groups such as crabs, mollusks, odonata, water birds, aquatic plants and fish. These various species represent a certain ecological and socio-economic interest because of their multiple roles. They are part of man’s diet and many other species. They also provide habitat and refuge for others such as aquatic plants. Mollusks, for example, are capable of containing many toxic chemicals and thus participating in the water purification phenomena. Together with odonata and birds, they represent bio-indicators of the ecological status of aquatic habitats.

However, despite the diversity and importance of species and habitats, freshwater ecosystems are facing strong pressure and disturbances linked to human activities, among others. To the contrary, even though dam construction responds to meeting economic needs, it can cause a lot of damage to aquatic species and their habitats.

The Organization for the Development of The Gambia River (OMVG) comprising The Gambia, Guinea, Guinea Bissau and Senegal, envisions the construction of a dam on the Sambagalou site. Based on impact studies undertaken, the construction of this dam will undoubtedly cause a loss of habitat. However, it is sometimes possible to compensate this loss by the protection and conservation of natural habitats.

Preliminary Plan for Freshwater Biodiversity Monitoring in the Gambia river basin Page 5 It is in this context that Wetlands International Africa, in partnership with the IUCN-Species Programme and the OMVG has agreed on the development and implementation of a monitoring plan for freshwater ecosystems biodiversity in The Gambia basin. This monitoring will provide important information on species and habitats and it represents an opportunity to document changes that might occur in the habitats. Hence, this will enable us take the necessary preventive or adaptive actions.

2. OBJECTIVE The overall objective of the plan is to ensure the use of information on freshwater biodiversity in development programs. It aims specifically to follow the changing trends of considered taxa and their habitats in The Gambia River basin.

3. METHODOLOGY

3.1. Species and key habitats concepts

The Gambia River basin hosts a great number of species and attracts many other species such as birds. This is due to the many services it provides but also because of its diversity of habitats (estuaries, marshes, swamps, mudflats, etc.). A habitat is a functional unit composed of different species that interact between them. The species are of great importance in maintaining the balance of habitats. These species, some of which are referred to as "keystone species", are essential in maintaining one or more communities. A keystone species may well be regarded as a species whose loss or elimination can cause a major change in the ecosystem. For instance, regarding plant species, they provide food for some animal species which are keystone species. The importance of keystone species is not illustrated by the size of their current population, but rather by the action they undertake to maintain a given community. Their disappearance leads to significant changes in the functioning of the ecosystem. Similarly, species that are prolific in nature and can be considered as key species is particularly true for invasive species.

In conservation biology, the term bio-indicator species is used to refer to species whose presence or change in their populations lead to changes in the environment or communities of other species. Keystone species play a fundamental role in maintaining biodiversity. Therefore, these species may act as biological indicators or bio-indicators and enable us to determine the state of the ecosystem.

Key habitats are habitats which are important so much so that their degradation or loss can affect one or more communities. According to Branquart (2004) key habitats are forest habitats that have a

Preliminary Plan for Freshwater Biodiversity Monitoring in the Gambia river basin Page 6 particularly high protective value (or wealth), because they host many rare and endangered species. Key habitats deserve to benefit from specific protection measures as regards their high protective value.

3.2. Site selection criteria

The selection of monitoring sites was made in preparation for the construction of the Sambagalou dam. It is therefore essential to take into account during the course of this selection the catchment area of the reservoir-- upstream and downstream of the dam. In addition, a site that will most likely not be affected by the dam has been taken into account (a control site). Considering these different positions, the selection of sites to be monitored is based on the following criteria:

o The site’s ecological importance o The role of site in biodiversity conservation o Species richness o The presence of rare or endangered species o Endemism areas or sites rich in endemic species o The ecological peculiarity (single habitat type or compulsory habitat for species or a given community).

3.3. Species selection criteria

During the first phase of the West Africa freshwater biodiversity assessment five freshwater taxonomic groups were selected and assessed based on the IUCN red list criteria. The taxonomic groups chosen were: fishes, plants, mollusks, odonates (dragonflies) and crustacean. Based on the regional assessment results the same taxonomic groups assessment results were brought at the level of the Gambia basin in this second phase. The results were reassessed for gaps by the researchers of the four country of the basin ( Senegal, Gambia, Guinea and Guinea Bissau). From the assessment some species were selected for monitoring based on the following criteria :  Endemic species

 Threatened species

 Rare species

 Characteristic species

 Economically important species

 Invasive species

 Potentially invasive species

 Species indicating the environmental status (e.g. pollution)

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4. PROPOSED SITES AND SPECIES TO BE MONITORED 4.1. Proposed sites to be monitored  Senegal

Sites Rationale Xcoord Ycoord

Site of Bara Close to the reservoir site

Ford of Damantan Data available 681853 ,76 1442636 ,35 Accessible Taxa: fishes, birds, plants, odonata, crabs and mollusks

Confluence point of the Interesting habitat because of the 680729 ,54 1440436,78 Gambia Niokolo changing levels of the Gambia river

Confluence point of the Interesting habitat especially when the 675636 ,48 1476535,31 Gambia Nieriko Gambia overflows The Nieriko is permanent, but undergoes a dry period at times with the dam Can be permanent

Simenti pond Habitat directly connected to the Gambia 684981 1400659 and an important habitat for wildlife

Kountadala pond Habitat directly connected to the Gambia 683367 1441236 and important habitat for wildlife and currently invaded by Mimosa pigra and Mytragina inermis

Wouring pond Permanent pond that is in the process of 683465,938 1462519,85 being colonized in some parts by Mimosa pigra. Deeper pond where there is always water, important habitat for wildlife, there is even a spawning area

Oudassi pond Interesting habitat especially when The 682850 1448089,714 Gambia river overflows Nieriko is constant, but undergoes a dry period at times with the dam Could be permanent

Preliminary Plan for Freshwater Biodiversity Monitoring in the Gambia river basin Page 8 Padan pond Important site when considering biodiversity conservation

Banthantity pond Important site when considering biodiversity conservation

Sambangalou site Important site because of the dam’s physical presence.

FIGURE 2: MONITORING SITES WITHIN SENEGAL AND GUINEAN GAMBIA BASIN

 Gambia : a. Lower River ecological site; area for fish breeding but also first Ramsar site

b. Central River Region, Reserve area (Manatee)

c. Upper River ecology; wet mountainous area,

d. Through the Fouta Djallon water.

Preliminary Plan for Freshwater Biodiversity Monitoring in the Gambia river basin Page 9 NOTE: There will probably be two more very important species for biodiversity in the lower-river region:

FIGURE 3: MONITONRING SITES WITHIN GAMBIA GAMBIAN BASIN

 Guinea Republic : a. Ecosystem sites where villages will be displaced: Kounsi in the CRD of Balaki;

b. Ecosystem sites where villages will be endangered: Théwiirè;

c. Home site: Pakaya (Mali urban commune district).

In the site selection process, the following areas were considered for better sampling:

 Those that will be flooded;

 Those that will suffer the future impact of the project;

 Those that will host displaced people

Based on what is already stated above, Guinean experts selected four sites including two sites that will be flooded.

The 4 identified sites contain the following ecosystems: Freshwater; Shrub lands; Savanna; Mountain; Bowes They are all located in the Bafing Faleme protected area and are rich in biodiversity.

Sites to be monitored in Guinea XCoord YCoord

1. Selected site to be flooded for surveys in Thiéwiré in 782354.07 1338809.07 Lébékéré rural development commune (CRD);

2. Selected site to be flooded for surveys in Parabanta in 192592.93 1344434.65 the Balaki rural development commune (CRD);

Preliminary Plan for Freshwater Biodiversity Monitoring in the Gambia river basin Page 10 3. Selected site that will be affected by the project’s 193178.67 1343228.76 future impacts for surveys in Kounsi in Balaki rural development commune (CRD). 4. Potential site to host the displaced Pakaya District in 814556.00 1340886.47 the urban commune of Mali which is the host site

FIGURE 4: MONITORING SITES WITHIN GUINEAN GAMBIA BASIN

4.2. Proposed species to be monitored 4.2.1. THE CRABS Only two species of crabs were identified in The Gambia river basin. Potamonautes ecorssei was collected in Wouroli Gué (Haute-Guinée), in Sanyiki près du Niokolo-Koba, in Niokolokoba and in Doufouroum between Niokolo-Koba and Banganré, and into Gambia River (Monod, 1969). Liberonautes latidactylus was found in Gué de Wouroli, Niokolo-Koba and into Gambia River .

Preliminary Plan for Freshwater Biodiversity Monitoring in the Gambia river basin Page 11

FIGURE 5: FRESHWATER CRABS WITHIN THE GAMBIA BASIN

Facing the ecological changes that are the consequence of hydro-power works in the Gambia basin, it becomes necessary to monitor the evolution of these two species. There might be a third species of small crab that are usually found in muddy environments.

4.2.2. THE MOLLUSKS Mollusks play an important role in the functioning of aquatic ecosystems. They are part of the diet of several species of aquatic vertebrates, especially fish. The mollusk populations participate in water treatment by inhaling many toxic substances (heavy metals, pesticides...). Because of their low mobility and life span, they are strong indicators of their environment’s ecological status.

4.2.3. Odonata

The odonata represent a significant heritage but they also occupy an important place in the structure and functioning of ecosystems and act as bio indicators on the quality of wetland habitats. The odonata are a valid tool to evaluate the degradation of habitat quality and were used as indicator by many authors.

We should however note that before undertaking the monitoring, it would have been wise to conduct an inventory during at least two to three years to complete the available information in the scientific literature on odonata wildlife in the basin. Such a study would enable to know the actual autochthonous species that were mentioned and draw the odonata spectrum of the habitats.

Preliminary Plan for Freshwater Biodiversity Monitoring in the Gambia river basin Page 12

FIGURE 6: FRESHWATER ODONATE WITHIN THE GAMBIA BASIN

4.2.4. BIRDS Water birds are defined as "a set integrating all taxonomic families, whose members are mainly birds who depend on wetlands for at least some part of their life cycle” (Rose & Scott 1994). These birds are excellent indicators on the status of habitats. Thus, we still agree that all surveyed species provide important information that contributes to the interpretation of results.

4.2.5. Plants

Aquatic plants play a very important role in aquatic ecosystems and more particularly in the oxygenation and water purification ecological processes. They are also used as habitat and food for animal species that live in these environments. For the human being, these aquatic plants are also used in various manners. However, it should be mentioned that these plants can sometimes be harmful, especially in cases where they proliferate at the expense of other species (invasive plants).

4.2.6. FISH

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FIGURE 7: FRESHWATER FISH WITHIN THE GAMBIA BASIN

5. DATA COLLECTION Obviously, the choice of method depends on the objectives set forth but undoubtedly on the means available for monitoring. The recommended methods in the monitoring plans must be simple methods, relatively flexible, inexpensive and easily applicable, as well replicable in the future to see changes over time. In the framework of this preliminary plan, it is necessary to develop a relatively simple protocol to monitor the general trends of flora and fauna. Because this plan is in line with an observatory meaning long-term monitoring, it may subsequently be strengthened by integrating much more precise and rigorous approaches, in order to document changes for both species and at the ecosystem levels.

5.1. Crabs The crabs can be collected by hand under stones, in cracks and rock crevices, embankment holes, vegetation etc. Afterwards, they will be preserved in alcohol.

Preliminary Plan for Freshwater Biodiversity Monitoring in the Gambia river basin Page 14 5.2. Mollusks

The sampling protocol will take into account the main types of environments: ponds, streams, tributaries and main river channel. Mollusks can be collected in a bucket (3 to 6 buckets per site), by hand or using a dip net. The collected samples are passed through a 1 mm sieve. In the laboratory, mollusks will be sorted, identified and counted. In each prospection site, on-field measurements of physio-chemical parameters will be undertaken: temperature, depth, bottom type, dissolved oxygen, salinity, nitrates and turbidity. These measures will be carried out using a multi-parameter portable, a depth meter and a Secchi disk.

 Parameters to record: the information that will be collected during the sampling campaigns focuses on environmental conditions (temperature, salinity, conductivity, dissolved oxygen, transparency, quantity of nitrates and phosphates, current strength, depth and bottom type) and habitats or populations (to determine the species of and number of collected mollusks, and the number of individuals collected per species).

 Data analysis and treatment

First, the identified monitoring indicators (species richness and abundance) will be calculated. Collected individuals will be identified until determining the species if possible in order to establish the species richness (number of species) of each prospection site. If there is any doubt in determining it, they will be sent to specialists. The species list will be established for each prospection site. A count of individuals collected per species will be conducted to determine the abundance of species in the samples. In a second phase, the Correspondence Factor Analysis (AFC) will be performed.

5.3. Odonata 5.3.1. Material to be used

 Butterfly net The butterfly net is made of a telescopic or fixed handle measuring approximately 1 to 2 m at the end of which is attached a metal ring with a diameter of 30 to 50 cm provided with a pocket of nylon, polyester or gauze that is more or less long and with various colors (white, green, black ...).

 Kick net

Preliminary Plan for Freshwater Biodiversity Monitoring in the Gambia river basin Page 15 The kick net is used to collect aquatic insects. It consists of a sturdy handle in one part, and a solid iron or aluminum circle of about 30 cm in diameter, provided with a nylon bag inside an empty grid of 800 to 300 microns, depending on the type.

 Boxes to collect exuviae  Ringlets to collect Imagos  Flexible entomological pliers  Cyanide jar  Sorting trays  Digital Cameras

A digital camera, suited for close-up shooting, is strongly recommended.

 Field Book The field book is needed to record all information relating to the observation (names of the observer(s), location, date, name of species, behavior, etc.).

5.3.2. Data collection

In each site, a number of stations will be identified according to the diversity of habitats. These habitats can be i) stagnant water: ponds, lakes or open marshes, forest ponds, mountain lakes ii) running water: streams and rivers with slow current, streams and rivers with troubled waters iii) calm parts of large rivers and iv) terrestrial environments that can be quite far away from water sources such as meadows, edges of woods, forest clearings.

Larvae, pupae and exuvia are being sought in aquatic habitat, more specifically in the water and aquatic vegetation. Imagos will be sought on the vegetation that covers these areas and on the trees and shrubs surrounding them.

In terrestrial environments that are more or less distant to aquatic habitats, adult in a maturing process will be sought in the meadows, edges of woods and forest clearings where they can reunite.

 Larvae and pupae

In the aquatic habitats, larvae and pupae are searched in the water and aquatic vegetation. The collection is done with the use of the kick net.

Preliminary Plan for Freshwater Biodiversity Monitoring in the Gambia river basin Page 16 After being mowed in the water, the content of the net is poured into a tray and is sorted by hand with flexible entomological pliers. The larvae are put in a vial containing 70% ethanol with a label bearing the date, place of harvest, habitat, geographic coordinates, and reference number. These same data are reported in the field notebook.

 Exuviae

The exuviae are searched on a band of approximately 50 cm on both sides of the bank along a length that depends on the habitat’s size (approximately 8 to 80 m). The exuviae that are found are then collected by hand, using a flexible entomological forceps and placed in the boxes provided for this purpose (one or more boxes per habitat). Just like the larvae and pupae, exuviae is able to determine the status of autochthonous species with certainty.

 Imagos (adults)

The Odonata adults are sought in the surrounding water points but also on land more or less distant from the aquatic habitats where adults in a maturation process meet. These are meadows, edges of woods and forest clearings.

Imagos are captured with butterfly nets. The individuals captured after being mowed are gently removed from the net pocket, avoiding holding them on their wings so as not to damage them. They are then put into the cyanide jar, which kills them quickly. Once dead, they are placed in ringlets with all the relevant reference (dates, collector’s name, harvest location, reference number, etc.). When the insects are not treated immediately after being collected, one must dry them in the sun for instance. Paradichlorobenzene can be put in the ringlets for better conservation.

Photographs of habitats and individuals (all ages) can usefully complete the information on the species and their environments.

5.3.3. Data treatment and analysis

Harvests are put in tubes containing ethanol 70°. The identifications that can be done locally will be done in the laboratory with the use of identification keys and/or with a comparison of reference samples. In some cases, genitalia preparations are necessary for species identification. One will then scour the genital parts to be mounted on a strip and compared them with the references.

The list of native species is derived from the identification of larvae, nymphs, exuviae and individuals in mating.

Preliminary Plan for Freshwater Biodiversity Monitoring in the Gambia river basin Page 17 However, it should be noted that with the changes of reproduction periods, one should regularly and closely monitor over a period of two or three years to get an exhaustive list of targeted habitats native species. We should also note that the odonata spectrum settlements depend on the list of native species.

In the qualitative realm, one will need to compare the settlements’ populations on one hand and a comparison of a settlement during the evaluation period (dry season and rainy season, from one year to another).

In the quantitative realm, the averages of individuals/species captured according to various seasons and years are compared. This will provide an indication on the populations’ evolution trend.

The counting of larvae and exuviae also give a good indication on the population size.

5.4. Birds

The distribution of water birds is closely linked to the availability of water and productivity of wetlands. The Gambia basin, owing to the diversity of its habitats and resources, hosts a large population of water birds. However, regular monitoring of these birds enables us to grasp their distribution and population trends. It is within this framework that the count of water birds in Africa (DOEA) can serve as reference to list the water birds already encountered in this basin. Moreover, it is important to know the conservation status (good or bad) of these important bird sites; because the smallest changes in these habitats may have serious consequences on bird populations. Thus, birds are excellent bio-indicators of environmental change.

5.4.1. Data collection

Monitoring will occur periodically in the different sites. In each site, geo-referenced counting points are selected and counting transects determined by the distance between two successive counting points. For small population, individual counting will be made; an estimate is made for large populations. Thus, for each identified bird species, the number of individuals is counted. The comments will be recorded on a counting card (ref. attached species sheet). The parameters related to habitat will be considered (ref. attached site sheet). This method enables the study of bird populations periodic changes in the sites and species encountered in different habitats.

5.4.2. Data analysis

Preliminary Plan for Freshwater Biodiversity Monitoring in the Gambia river basin Page 18 A database will be created to triangulate the bird records (species richness, abundance, dominance) with different environmental parameters (vegetation, water level, human impacts).

5.5. Plants For plants, monitoring can be done at different levels (on the physiognomic scale, across communities or ecosystems, across populations or species or even at the genetic level. In the context of this work, we limit ourselves to monitoring across ecosystems and species. The first refers to the vegetation structure itself that can be appreciated through the physiognomy, which is particular to a given plant community.

5.5.1. Data collection

Phyto-sociological methods are generally used to study aquatic plant communities. The transect method is the most common. Transects are able to measure changes from one community to another due to environmental gradients such as moisture. They are indicated by a stretched wire and attached at both ends. Along these transects, frames measuring 1 m x 1 m will be installed using a string and the angles will be marked with stakes. Data will be collected in these clearly defined plots. As for the herbaceous, growing square will be used while for the high timber, 100 x 100 square meters with five 20 x 20 sub-squares will be used; Hence, this will create the floristic list and species status as well as the environmental value of the ecosystems.

5.5.2. Parameters to collect

- It is important to geo-reference the sites and mark them in order to locate the sites for future visits.

- The water physio-chemical characteristics should be taken into account. These are namely pH, oxygen and other chemical elements such as nitrates, phosphates, potassium, etc. that should be measured.

- The floristic list: All species present in the plots will be listed. And those that will not be identified in the field will be collected and subsequently identified using herbarium.

- Recovery: it is estimated using both the abundance (relative number of individuals of a species in relation to the total number of individuals identified in the plot or frame) and dominance (covered area, i.e. the projection on the ground of foliage coverage of all individuals of the targeted species). This is found through the ratio of abundance-dominance determined by the Braun-Blanquet scale. These factors vary based on the recovery.

Preliminary Plan for Freshwater Biodiversity Monitoring in the Gambia river basin Page 19 Table: Factors of the Braun-Blanquet abundance dominance scale

Factors Recovery (R)

5 R > 75 %

4 50% < R <75 %

3 25 %

2 5 %

1 R <5 %

+ Rare

Note: Statement sheet: It is very useful to elaborate a statement sheet that includes the following: - Date - Location - Transect orientation - Number of transects - Number of plots - Species

5.5.3. Data analysis

For each species, the following parameters will be calculated: abundance, density, recovery, dominance, frequency, relative frequency, relative dominance and importance value.

Abundance: the total number of individuals of each species in the total sample. Recovery: the area occupied by individuals of a species. It is estimated using the projection on the soil of the foliage coverage Density: the number of individuals belonging to a species per area unit. Relative density: the density of a species in relation to the density of all species. Dominance: the area occupied (using the recovery) by a species in a settlement, per area unit. Relative dominance: the area occupied by the species, using the recovery, in relation to the area occupied by all species

Preliminary Plan for Freshwater Biodiversity Monitoring in the Gambia river basin Page 20 Frequency: the distribution of a species in a settlement, i.e. the percentage of frames in the sample, where one can find individuals of a species. Relative frequency: the distribution of species in relation to the distribution of all species in the sample Important value: This is a composite index of relative density, relative dominance and relative frequency which is the structural role of a species in a settlement. The important value is also used to compare settlements between them, in terms of species composition and settlement structure. VI = relative density + relative dominance + relative frequency

5.6. Fish

5.6.1. Data collection

Experimental fishing will be done by using a battery of gill nets measuring 10 to 40 mm on the side of the basin and 10 to 60 mm on the estuary side. Fish caught during the campaign will be identified to determine the species, measured and counted. The gender of individuals and the sexual maturity stages of the main species will be determined. Longlines traps and lines will be used. A sensitivity electronic balance weighing 1 gram should be used.

5.6.2. Data analysis and treatment

First, the identified monitoring indicators (species richness and abundance) will be calculated. Collected individuals will be identified until determining the species if possible, in order to establish the species richness (number of species) of each prospection site. If there is any doubt in determining it, the individuals will be sent to specialists. The species list will be established for each prospection site. A count of individuals collected per species will be conducted to determine the abundance of species in the samples. In a second phase, the Correspondence Factor Analysis (AFC) will be performed.

6. MONITORING INDICATORS Monitoring indicators will highlight the changing trends of species and their habitats. The indicators are relatively numerous and can even be composed of a species or group of species which presence

Preliminary Plan for Freshwater Biodiversity Monitoring in the Gambia river basin Page 21 inform us on the environment’s characteristics or the influence of other factors on the environment. These indicators should be simple and easily understood by the various groups that will be responsible for the monitoring.

6.1. Crab monitoring indicators

To evaluate and monitor the quality of crabs’ key habitats, the following indicators may be used:  Average Biomass (B) It is determined by area unit and it enables the distinguishing of the settlements’ spatial and temporal variations  Abundance (A) The abundance is determined by the number of individuals of a species

6.2. Mollusk monitoring indicators

The composition and structure of animal populations are directly influenced by environmental conditions. Mollusks are proving to be good indicators to assess the status of habitats where they grow. Their limited mobility prevents them from fleeing when there are disturbances in the environment, which permits them to provide a reliable illustration of the environmental conditions where they live, unlike fish and other mobile species. Many studies showed that the installation of a freshwater reservoir supports the abundance of mollusks with lentic affinity (Mollusques Gastéropodes pulmonés, et autres Bivalves)). In addition, the reservoirs create the favorable conditions for the development of the plants which constitute an excellent habitat for several mollusc species. The building of the dam and the other related infrastructures could cause a fragmentation of the habitats regarded as one of the most important factors of disappearance of the species. The reduction of the flood plains downstream from the dam could cause the a reduction in the abundance of mollusks. After the construction of the dams, the oxygenated running water are often replaced by calm waters. These new hydrological conditions could be unfavourable to the mollusc species of running water such as Mutela dubia dubia and Aspatharia dahomeyensis.

Several types of methods (univariate and multivariate) are used to analyze changes in mollusks’ population structure. Because of their simplicity and simple calculation, some univariate methods have been preferred over a long period of time. These techniques permit to characterize the communities’ general trends,

Preliminary Plan for Freshwater Biodiversity Monitoring in the Gambia river basin Page 22 study their variations and deduct the underlying causes. However, they do not take into account the species and do not consider changes in specific composition (Grall et al., 2006). Being more sensitive than univariate methods in general, multivariate methods are relatively recent because their use requires computer materials and specialized and powerful softwares (Grall et al., 2006). However, they are much more complex compared to other techniques, they require significant work on data preparation and processing and interpretation of results is often difficult, limiting their use by developers (Grall et al., 2006). For this study, we suggest the use of methods with one single descriptor that are easier to interpret. Two measures could be used to evaluate the effects of hydraulic works on mollusks’ species: 1) Abundance of species determined by the number of individuals The Abundance is determined by the number of individuals of a species in the sample. 2) Species richness (S) The richness and abundance of bivalve mollusks can provide information on the general

quality of the ecosystem. The composition and the structure of the settlements directly reflect the disturbances which the organism undergo. If the dam is effectively operating, the various reactions of the species will be translated at the level of their abundance and number. Facing changing of environmental conditions, the species will go through three types of reaction according to their sensitivity (Grall et al., 2006):  The most sensitive will disappear Because of their sedentariness (cannot flee), large the bivalves are very sensitive to the changes of the environmental physical conditions (pollution, turbidity, hydrology). These large bivalves are represented in the basin of Gambia by the following species:

Coelatura aegyptiaca Mutela dubia dubia Aspatharia dahomeyensis. Pleidon ovatus Etheria elliptica -  The indifferent will maintain themselves  The tolerant and opportunistic will take advantage of the newly introduced conditions and develop themselves

It is also based on the model of Pearson and Rosenberg (1978) predicting that the more the disturbance is strong the weaker the specific richness is

Preliminary Plan for Freshwater Biodiversity Monitoring in the Gambia river basin Page 23 3) This pecies richness can be used to analyze the settlement’s taxonomic structure (e.g. number of mollusks species). It is also able to distinguish spatial variations: the fauna rich areas and poorer areas as well as temporal variations: the minimum and maximum depending on seasons and stations (Grall et al., 2006). However, it contains a drawback in that it is highly dependent on sample size (number of species sampled increases with the surface sampled) and habitat type (species richness varies according to substrate type, depth and salinity).

In addition to these two parameters, it would also be necessary to measure water physio- chemical parameters given the importance they can have on the environment’s general conditions and mollusks species distribution. These parameters are: temperature, turbidity, depth, bottom type, dissolved oxygen, vegetation, content of nitrates and phosphates.

6.3. Odonata monitoring indicators

the monitoring indicators are :

1. The diversity of autochtones Odonates habitats (spectrum odonatologic). This diversity, once known, will make it possible to monitor the appearance or the disappearance of species in relation to the implementation of the dam in the selected habitats.

2. The relative abundance of the populations during sampling (captured exuvies, individuals); this indicator will make it possible to evaluate the population’s fluctuation of the species in

relation to the implementation of the dam.

3. 10. The larval odonatologic productivity will make it possible to evaluate the rate of

reproduction of the species to be monitored in the selected habitats.

3.4. Bird monitoring indicators

The indicators to monitor birds are:

 Species richness

 Abundance

 Dominance

 The environmental parameters (vegetation, water level, human impacts).

Preliminary Plan for Freshwater Biodiversity Monitoring in the Gambia river basin Page 24 These parameters are important for bird monitoring. The Species richness gives the number of species found in the area before giving their status (endangered or not). The abundance linked to Species richness will give the trends of all species (stable, increasing, decreasing, or unknown. The dominance will give an idea of species or group of species which are dominant in different habitats. All these will be analysis according to environmental parameters such as vegetation fluctuation, water quality and quantity, pollution, and other human impacts. With the implementation of the dam the changes are expected to happen on those indicators for rhe bird to be monitored.

6.5. Plant monitoring indicators

The construction of the dam will induce probably some modifications in the ecosystem that’s why; it is important to elaborate indicators which can be used for the monitoring. Regular quantitative data concerning specific composition and species dynamic through these following parameters will inform about ecosystem changes.  The population size (species whose populations are decreasing or those whose populations are prolific ;)

 The abundance of species

 The distribution of species

 The change in floristic composition

 The species richness

 The presence of exotic species

6.6. Fish monitoring indicators These indicators will be determined on two levels: species and habitats.

• For species, four metrics are taken into account:

 Catch effort per unit (PUE) which indicates the relative abundance of species.

 The average relative length of individuals. For each individual, we will calculate its length in relation to the minimum (m) and maximum (M) observed for individuals of the same species in all fisheries: (observed length-m) / (Mm). Individual values are then averaged per fishing. The lower the value one can assume that the population consists of young individuals, as it was also confirmed by the correlation which was observed during the Garafiri dam impact study Garafiri (IRD-BCEOM-BRLI, 2003) between this variable and

Preliminary Plan for Freshwater Biodiversity Monitoring in the Gambia river basin Page 25 the percentage of juvenile individuals in the settlement. This variable should increase if a disturbance reduces the recruitment.

 The relatively average condition factor. The condition factor (K = P/L3, P= body weight in grams, L = length in cm) will be calculated for all individuals, then converted to relative value given the maximum and minimum observed for each species in all fishing. Individual values are then averaged per fishing. A low value corresponds to a low status of individuals throughout the population.

 The percentage of mature individuals: Proportion (%) of mature individuals by the total number of individuals will be calculated. A low value may indicate a disruption of reproduction.

• For habitats: One should note that many methods have been developed to quantify the impact of disruptions that the streams on ecological systems experience. With regard to fish populations, an approach that is increasingly used, including in the tropics is the index of biotic integrity (Index of Biotic Integrity or IBI) developed first in North America (Karr 1981).

6.7. Fish monitoring indicators These indicators will be determined on two levels: species and habitats.

• For species, four metrics are taken into account:

 Catch effort per unit (PUE) which indicates the relative abundance of species. This metric is based on the fact that in a disturbed realm the density of species is supposed to be less than in an undisturbed one.

 The average relative length of individuals. For each individual, we will calculate its length in relation to the minimum (m) and maximum (M) observed for individuals of the same species in all fisheries: (observed length-m) / (Mm). Individual values are then averaged per fishing. The lower the value one can assume that the population consists of young individuals, as it was also confirmed by the correlation which was observed during the Garafiri dam impact study Garafiri (IRD-BCEOM-BRLI, 2003) between this variable and the percentage of juvenile individuals in the settlement. This variable should increase if a disturbance reduces the recruitment. Increase of this variable indicates that there is less number of fish reaching the adult age.

Preliminary Plan for Freshwater Biodiversity Monitoring in the Gambia river basin Page 26 Average length and average relative length are differents concepts; What is taken here into account is the second one which give indications of rate of young individuals among the population. The average length is another concept which indicate to what extend, i.e up to what length. a species can grow up. Changing in average length may indicate overfishing or a very poor biological productivity of an environnemnt as it has been documented for two marine species, Galeoides decadactylus and Pseudotolithus senegalensis that showed a shorter maximum length in the coast of Biafra than off Congo and Ivory Coast.

 The relatively average condition factor. The condition factor (K = P/L3, P= body weight in grams, L = length in cm) will be calculated for all individuals, then converted to relative value given the maximum and minimum observed for each species in all fishing. Individual values are then averaged per fishing. A low value corresponds to a low status of individuals throughout the population.

 The percentage of mature individuals: Proportion (%) of mature individuals by the total number of individuals will be calculated. A low value may indicate a disruption of reproduction, i.e., reproduction of species with low value is affected by the disturbance

• For habitats: One should note that many methods have been developed to quantify the impact of disruptions that the streams on ecological systems experience. With regard to fish populations, an approach that is increasingly used, including in the tropics is the index of biotic integrity (Index of Biotic Integrity or IBI) developed first in North America (Karr 1981).

Index of Biotic Integrity

The originality of this index is to take into account certain descriptors (metric) reflecting the functioning and diversity of fish populations and whose response to a disturbance of the environment is already known. Such an index has been developed for the Konkoure basin in a previous study (Hugueny et al 1996) and its effectiveness was tested during the impact study of the pollution of a bauxite processing factory.

To calculate the IBI, one will use the same metrics as those defined for the Konkouré (Hugueny et al 1996) in addition to indicators of condition, reproduction and recruitment:

‐ Metric 1: Number of species per fishing. This metric is based on the assumption that a disturbed environment has fewer species than an undisturbed one because species intolerant to disturbance (s) will not be there

Preliminary Plan for Freshwater Biodiversity Monitoring in the Gambia river basin Page 27 ‐ Metric 2: Number of Mormyrides species.

‐ Metric 3: Number of Cichlides species.

‐ Metric 4: Number of great benthic Siluriforms species.

‐ Metric 5: Percentage of individuals belonging to omnivorous species. The number of omnivores is supposed to increase in disturbed environments where more specialized food sources are rare or absent. Subsequently, the inverse of this metric is added to the final IBI (see below).

‐ Metric 6: percentage of individuals belonging to invertivores species.

‐ Metric 7: percentage of individuals belonging to piscivorous species at an adult stage without necessarily being strictly piscivorous.

‐ Metric 8: Total PUE (in numbers) per fishing. In a disturbed environment the species density is supposed to be less than that observed in an undisturbed environment.

The metric 1 to 4 report on the settlement’s functional diversity determined by the number of species found in different taxonomic categories. The underlying assumption is that a disrupted settlement will be less diversified than a non-disrupted settlement.

Metrics from 5 to 7 take into account the trophic structure, with the underlying assumption that individuals on a special diet will be disadvantaged compared to omnivores facing a disruption affecting food resources.

After being centered and reduced (multiplied by -1 in the case of the metric 5) the other 8 metric are added to form the IBI. Low IBI values are then interpreted as resulting from the possible action of one or more environmental disturbances.

In addition to the initial metric, we took into consideration 3 additional features:

 Relative average length of individuals

 Relative average condition factor

 The percentage of mature individuals.

These three variables are centered, reduced (multiplied by -1 in the case of the relative length) and aggregated to the IBI which is more sensitive to disturbances that can be induced on the biology of

Preliminary Plan for Freshwater Biodiversity Monitoring in the Gambia river basin Page 28 species (reproduction and condition). To be clearer these 3 metrics give indications on reproduction (relative average length and percentage of mature individuals) and feeding condition (Relative average condition).

Measurement of physio-chemical parameters:

To assess the quality of fish habitats, it would also be necessary to measure water physio-chemical parameters on the following elements: dissolved oxygen, salinity, depth, temperature, nature of substrate, nitrate, phosphate and toxic chemicals.

7. MONITORING FREQUENCY Within the framework of the species monitoring, it is important to clearly describe the frequency of the monitoring which is related to the time interval to which the data must be collected. The period of collection constitutes a determining factor in the nature of the results which will be obtained. Indeed, according to the species and according to the periods of the year (for example rainy and dry season), there is important variations of biological information of the species. For each taxon, a

frequency of monitoring was described.

7.1. Crabs

Bi-annual (one in dry season and another one in rainy season) sampling campaigns will be conducted to better understand the composition and distribution of species and the inter-season variability in the relative abundance of different species

7.2. Mollusks Bi-annual (one in dry season and another one in rainy season) sampling campaigns will be conducted to better understand the composition and distribution of species and the inter-season variability in the relative abundance of different species

7.3. Odonata

Sampling will be done during the dry and rainy seasons, once every three years.

7.4. Birds

For the first year, a bi-monthly sampling should be undertaken in all identified sites in order to see the population dynamics according to the environmental parameters.

7.5. Plants

Preliminary Plan for Freshwater Biodiversity Monitoring in the Gambia river basin Page 29

The first monitoring will be conducted twice a year in the different sites already identified. The first will be conducted during the dry season between March and April, and the second towards the end of the rainy season between September and October. After an initial visit which will serve as baseline, the monitoring must continue every year in order to provide maximum information that may help at some point to assess evolution trends of flora and aquatic and semi-aquatic vegetation.

7.6. Fish

The first exploratory mission to select monitoring sites (GPS positions) and collection of general information on the environment must be undertaken. Afterwards, four quarterly sampling campaigns will take place at significant periods of the seasonal hydrologic cycle of The Gambia river

‐ August / September: characterizing the rainy season

‐ October / November / December: characterizing the end of the rainy season

‐ February / March / April: characterizing the dry season

‐ May / June / July: characterizing the beginning of the rainy season

8. ACTORS AND PARTNERS INVOLVED IN THE MONITORING

The actors of the four OMVG member countries will ensure monitoring. These actors will consist of the Ministries in charge of the Environment, research institutions, local collectivities, NGOs, community-based organizations that will monitor the field. These actors are supported by partners such as OMVG, Wetlands International Africa and other NGOs.

PARTNERS

ORGANIZATION FOR THE DEVELOPMENT OF THE GAMBIA RIVER (OMVG)

WETLANDS INTERNATIONAL International Union for the Conservation of Nature (IUCN)

ACTORS

GAMBIA

National Environmental Agency (NEA),

Preliminary Plan for Freshwater Biodiversity Monitoring in the Gambia river basin Page 30 Ministry of Natural Resources and Environment

Department of Water Resources

Department of Lands and Surveys

Soils and Water Management Unit

Universities and research institutions

Local collectivities

African Union, FAO, GEF and USAID Office for the international coordination of the Fouta Djallon

The Green Gambia (Gambia) NGOs and actors from the civil society

GUINEA

MINISTRY OF ENVIRONMENT

UNIVERSITIES AND RESEARCH INSTITUTIONS

LOCAL COLLECTIVITIES NGOs and structures working in the environment SECTOR

GUINEA-BISSAU

MINISTRY OF ENVIRONMENT

MINISTRY OF NATURAL RESOURCES AND ENERGY

UNIVERSITIES AND RESEARCH INSTITUTIONS

NGOS AND STRUCTURES WORKING IN THE ENVIRONMENT SECTOR Local Collectivities

SENEGAL

Ministry of Environment, protection of nature, artificial lakes and retention basins

UNIVERSITIES AND RESEARCH INSTITUTIONS

LOCAL COLLECTIVITIES

NGOS AND STRUCTURES WORKING IN THE ENVIRONMENT SECTOR

Preliminary Plan for Freshwater Biodiversity Monitoring in the Gambia river basin Page 31

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ANNEXES

ANNEXES

Annexe 1 : Proposed list of crabs to be monitored

Species Selection criteria Habitat

Potamonautes Less common Species Main river bed, streams and permanent ecorssei ponds.

Liberonautus Common species Main river bed, streams and permanent latidactylus ponds.

Annexe 2: Proposed list of mollusks to be monitored

Species Selection criteria Habitats

Coelatura aegyptiaca Common Species but In sand or vase bottom between the threatened pebbles or stones

Mutela dubia dubia Common Species but Running water threatened

Aspatharia Common species in the Running water dahomeyensis. basin but threatened

Pleidon ovatus Present in the region Unknown ecology

Corbicula fluminalis Fairly common species but sandy and mud-sandy bottom threatened

Bellamya unicolor Very common species in the Bottom, sediment scraps of papyrus Gambia rhizomes, on the banks or on aquatic plants.

Preliminary Plan for Freshwater Biodiversity Monitoring in the Gambia river basin Page 37 Etheria elliptica Rarely Stony or rocky bottom and on rocky beaches of certain lakes in Africa

Annexe 3: Proposed list of odonata to be monitored

Species Selection criteria Habitat

Common species Lestes dissimulans Swamps, ponds, marshes with herbaceous vegetation, calm streams

Common species Lestes ochraceus Open ponds and slow streams.

Common species Lestes tridens Streams, on the lakes’ edges Common species but not Chlorocnemis rossii evaluated Rivers located at an altitude of 450 to 500 meters, in forest and savannah.

Common species Elattoneura nigra Streams and rivers, in wooded areas.

Species not evaluated Elattoneura pluotae but might be endemic in Shaded streams West Africa

Species not evaluated Mesocnemis dupuyi but might be endemic in Rivers, in savannah West Africa

Common species Mesocnemis singularis Rivers, streams and lakes, in savannah or forest

Common species Platycnemis sikassoensis Rivers not covered, in forests.

Common species Africallagma subtile Streams, ponds, swamp rivers

Common species Agriocnemis exilis Swamps, ponds, swamp rivers

Common species Swamp forests. Agriocnemis maclachlani Common species Swamps. Agriocnemis victoria Common species Swamps and ponds in arid areas. Agriocnemis zerafica Common species Ponds in dry areas Ceriagrion bakeri

Preliminary Plan for Freshwater Biodiversity Monitoring in the Gambia river basin Page 38 Common species Ceriagrion corallinum Swamps in or near a forest.

Common species Ceriagrion moorei Ponds and streams, in open savannah. Common species Ceriagrion suave Ponds and streams, in open and dry savannah.

Common species Ceriagrion whellani Swamp areas Common species Pseudagrion camerunense Rivers in open environments Not evaluated but in a Pseudagrion epiphonematicum restricted range Along water streams covered in dense forest

Common species Streams and rivers, in savannah Pseudagrion glaucescens Common species Streams and rivers, in savannah Pseudagrion hamoni Common species Pseudagrion kersteni Streams and troubled rivers in different habitats, below 1,800 m.

Common species Pseudagrion massaicum Streams and rivers, in forest. Common species Pseudagrion melanicterum Streams, in forest. Common species Pseudagrion nubicum Lakes and swamp rivers where reeds grow.

Common species Pseudagrion sjoestedti Ponds, streams and rivers, in forest.

Common species Pseudagrion sublacteum Streams and rivers. Common species Pseudagrion sudanicum Open rivers, in forest. Common species Pseudagrion torridum On the edges of lakes with reeds.

Common species Phaon iridipennis Streams and rivers with gallery forests, in savannah.

Not evaluated Sapho ciliata Mid water streams located on foothills

Preliminary Plan for Freshwater Biodiversity Monitoring in the Gambia river basin Page 39 Not evaluated Sapho fumosa Water streams in forest, often in mountain.

Not evaluated Umma infumosa Along water streams, from the foothills to the edge of the forest around 1200 m.

Not evaluated Chlorocypha dispar From the foothills up to 950 m, seems to show cast a plastic ecology.

Common species Anax tristis Ponds and rivers, in open environments.

Common species Heliaeschna fuliginosa Open rivers, in forest. Common species Crenigomphus renei Lakes and slow-flowing rivers, in savannah.

Common species Neurogomphus featheri Forests and savannahs. Not evaluated Idomacromia lieftincki Fast streams and rivulets flowing from the foothills, around 500 m, found in Dindéfello (Legrand, 2003).

Common species Phyllomacromia africana Rivers, forests or woodlands. Common species Phyllomacromia pseudafricana Rivers, in the bush. Common species Acisoma trifidum Streams, in forest. Common species Aethiothemis palustris Information not available Common species Aethiothemis solitaria Swamps with reeds Common species Aethriamanta rezia Ponds, streams and rivers with slow currents, edges of lakes with dense aquatic vegetation.

Common species Brachythemis lacustris Streams and rivers, savannahs and woodlands.

Preliminary Plan for Freshwater Biodiversity Monitoring in the Gambia river basin Page 40 Common species Bradinopyga strachani Pond on armor, in an open habitat.

Common species Chalcostephia flavifrons Swamps in savanna. Common species Crocothemis divisa Ponds, streams and rivers in forest areas

Common species Diplacodes lefebvrei Cleared swamp habitats. Common species Diplacodes luminans Often seasonal swamps, in savannah. Common species Hadrothemis defecta Damp forest Common species Hemistigma albipuncta Swamps, in savanna and woodland or forest.

Common species Olpogastra lugubris Cleared rivers but also streams and lakes.

Common species Orthetrum angustiventre Woodland and forest galleries. Common species Orthetrum brachialis Swamps, savannahs and woodlands. Common species Orthetrum guineense Cleared streams Common species Orthetrum hintzi Ponds and streams, in savannahs and woodlands or forests.

Common species Orthetrum icteromelas Swamps, streams and forested floodplains.

Common species Streams, in forest. Orthetrum Julia Common species Streams, in forest. Orthetrum microstigma Common species Orthetrum monardi Swamp forests. Common species Orthetrum stemmalis Ponds and swamps, in forest. Common species Oxythemis phoenicosceles Ponds of damp forests, floodplains, swamps.

Common species Palpopleura lucia Swamp habitats, in savannah and forest.

Common species Palpopleura Portia Swamps in savannah and woodland.

Preliminary Plan for Freshwater Biodiversity Monitoring in the Gambia river basin Page 41 Common species Parazyxomma flavicans Stagnant water, in/near a forest.

Common species Rhyothemis notata Streams, in forest. Common species Tetrathemis camerunensis Ponds and streams with slow currents, in damp forest.

Common species Trithemis dichroa Ponds and streams, in forest. Common species Trithemis grouti Streams, in forest. Common species Trithemis hecate Swamps, streams with slow current, in savannah and woodlands.

Common species Trithemis monardi Swamp ponds and rivers, in woodlands.

Common species Trithemis nuptialis Streams, in forest. Common species Trithetrum navasi Swamps Common species Urothemis assignata Ponds, lakes or streams with slow current and rivers, in savannah, in woodlands.

Common species Urothemis edwardsi Ponds, lakes, floodplains or streams with slow current, savannah and woodlands.

Annexe 4: Proposed list of birds to be monitored

Species Selection criteria Habitats

Amaurornis flavirostra Less common species Swamps

Haematopus ostralegus Migratory Palaerarctic On the coast

Less common

Philomachus pugnax Migratory Palaerarctic Swamps and rice fields

Common

Gallinago gallinago Migratory Palaerarctic Swamp areas

Common to less common

Preliminary Plan for Freshwater Biodiversity Monitoring in the Gambia river basin Page 42 Limosa limosa Migratory Palaerarctic Rice fields or freshwater swamps

Common

Phoenicopterus minor Less common Lakes

Ciconia nigra Migratory Palaerarctic Delta

Less common

Ardea purpurea Migratory Palaerarctic Delta

Common

Leptoptilos crumeniferus Rare On land

Nests on trees

Ephippiorhynchus Rare Delta

senegalensis Nests on trees

Annexe 5: Proposed list of plants to be monitored

Species Selection criteria Habitats

Acroceras amplectens Common species Permanent or temporary shallow waters

Swamps, rice fields, lakes and rivers

Aeschynomene afrspera Common species Waters deep enough, rice fields, eutrophic environments

Aeschynomene crassicaulis Common species Waters deep enough, rice fields, eutrophic environments, participates in floating rafts

Aeschynomene elaphroxylon Common species and Waters deep enough, rice fields, eutrophic participates in floating environments rafts

Aeschynomene tambacoundensis Endemic in West Africa Deep enough waters, rice fields, eutrophic environments

Aldovanda vesiculosa Rate species Calm and clear waters, oligotrophic, permanent and deep enough

Preliminary Plan for Freshwater Biodiversity Monitoring in the Gambia river basin Page 43 Aponogeton subconjugatus Endemic in West Africa Ponds not very deep that have been flooded for a long period, muddy

Areas flooded by the river

Azolla africana Proliferous species Ponds, temporary rivers arms, often temporary muddy waters

Bergia capensis Common species Often muddy ponds, waters more or less temporary, euthrophic, rice fields

Bolboschoenus grandispicus Vulnerable species Flooded depressions on the coast

Caperonia sengalensis Vulnerable species Flooded ponds, ricefields

Ceratophyllum demersum Vulnerable species Calm, deep, permanent waters ; mostly eutrophic environments

Ceratophyllum submersum Vulnerable species Calm, deep, permanent waters ; mostly eutrophic environments

Cyperus latericus Endemic, rare and Relatively important settlements along borders of endangered in Senegal ponds on a lateritic slab

Echinochloa colona Common species Permanent or temporary waters

Echinochloa stagnina Common species Permanent or temporary waters

Eichhornia natans Common species Moderately deep, or /almost permanent clear waters ;

Ponds, lakes, streams, rice fields

Eleocharis deightonii Endemic in West Africa Flooded rice fields or recently dewatered swamps

Eriocaulon meklei Endemic in West Africa Temporarily flooded marshes ; swamps

Floscopa axillaris Endemic in West Africa Shallow, permanent or temporary waters ; swamps, rice fields

Heliotropium indicum Common species

Hygrophila africana Common species Temporary ponds

Hygrophila barbata Endemic in West Africa Swamp meadows, rice fields

Hygrophila niokoloensis Rare species??

Hygrophila odora Endemic in West Africa On the borders of water, in particular on the Gambia river

Hygrophila senegalensis Endemic in West Africa Swamp meadows

Ipomea aquatica Common species Swamps, humid locations

Preliminary Plan for Freshwater Biodiversity Monitoring in the Gambia river basin Page 44 Isoetes melanotheca Endemic in West Africa Swamps

Ledernaniella abbayesii Endemis in Guinea Humid rocks

Leersia hexandra Common species Swamp depressions, along borders of ponds

Lemna aequinioctalis Common species Watercourse, lake

Ludwigia adcendens Common species and Ponds, flooding areas, calm rivers, often muddy participates in the temporary waters ; floating rafts Usually eutrophic environments, slightly brackish and oligotrophic

Ludwigia leptocarpa Common species and Flooded areas, drained sands, along lakes, swamps participates in the floating rafts

Monochoria brevipetiolata Common and endemic to Temporary ponds on rocks or bowé West Africa

Najas welwitschii Endemic, rare and Clear waters on bowé or rocks, temporary muddy endangered in Senegal ponds, rice fields

Neseae crassicaulis Common species Flooded ponds, shallow, temporary and often muddy waters

Ditches, rice fields

Nymhoides guineense Common and maybe Oligotrophic ponds on rocks endemic in West Africa

Nymphaea lotus Common species Eutrophic muddy ponds

Nymphaea micrantha Common species Eutrophic muddy ponds

Nymphoides indica Common species Rice fields

Oryza barthii Common species Watered ditches, ponds and flooded soils

Oryza longistaminata Common species Stagnant waters

Panicum anabaptistum Common species Flooded plains, watercourse banks and beds

Phragmites australis Proliferous species Ponds, torrent beds

Pistia stratiotes Proliferous species Ponds, watercourse bays

Polygonum seneglense Common species Permanent wonders, eutrophic environments, ponds, ditches, rice fields

Potamogeton octandrus Proliferous species Permanent deep waters, lakes, calm streams

Potamogeton schweinfurthii Proliferous species Permanent deep waters, lakes, calm streams

Preliminary Plan for Freshwater Biodiversity Monitoring in the Gambia river basin Page 45 Pycreus mundtii Common species Muddy waters or with slow current

Raphia palma-pinus Species likely endemic Swampy thickets in West Africa

Raphia sudanica Likely endemic in West Swamps, near water points Africa

Rhynchospora corymbosa Common species Swamps, near fresh water, flooded rice fields

Rotala stagnina Rare species More or less temporary ponds on sands, rocks or bowé, streams

Clear shallow waters

Rotala tenella Rare species More or less temporary ponds on sands, rocks or bowé, streams

Clear shallow waters

Rytachne furtiva Endemic in the sub- Floodplains region and vulnerable

Sphenoclea dalzielii Likely endemic in West River flood areas or rice fields Africa

Thalia welwitschii Common species Swamps

Typha domingensis Proliferative species Water courses, ponds, lakes

Utricularia inflexa Common species Calm waters ; floodplains

Utricularia reflexa Common species Calm waters ; floodplains

Vetivera nigritana Common species Flooding areas

Vossia cuspidate Common species Temporary calm waters, sometimes profound

Ziziphus spina-christi Common species Near rivers with strong flooding

Wolffia arrhiza Stagnant fresh waters, eutrophic ponds sometimes almost brackish sometimes

Annexe 6 : Additional List of plants

1. Mimosa pigra ; 2. Mitragyna inermis ; 3. Mimosa pudica (invasive exotic) 4. Stylosenthes sp. (used by antelopes for food purposes); 5. Nelsonia canencens (fertility indicator?);

Preliminary Plan for Freshwater Biodiversity Monitoring in the Gambia river basin Page 46 6. Borrasus aethiopum (great economic value and endangered); 7. Elaeis guineensis (great economic value and endangered) ; 8. Alchornea cordifolia (water retention); 9. Centella asiatica ; 10. Guiera senegalensis (dryness indicator status); 11. Calotropis procera (dryness indicator status); 12. Pandanus candelabrum (depletion); 13. Carapa procera (depletion); 14. Dialium guineensis (depletion); 15. Pseudospondias microcarpa (depletion); 16. Euphorbia sudanica (depletion) 17. Sapium ellipticum (depletion); 18. Spondias mombin (Endangered: Guinea monograph); 19. Syzygium guineense (depletion); 20. Uapaca heudelotii (depletion); 21. Xylopia aethiopica ;

Annexe 7: Proposed list of fish to be monitored

Species Selection criteria Habitats

Lates niloticus Common species but not Sandy, rocky and muddy bottoms evaluated, unlisted Vegetation zones Calm, stagnant or current waters Channel, lakes and irrigation channels Hyperopisus bebe bebe Common species but not Demersal species living exclusively in freshwater evaluated, unlisted under a tropical climate

Schilbe micropogon Endemic species of West Demersal species living exclusively in freshwater Africa’s coastal basins under a tropical climate

Schilbe mystus Common species but Stagnant deep waters, shallow marshes and classified as vulnerable occasionally in shallow floodplains. because of excessive exploitation

Hemichromis fasciatus Common species but not Benthopelagic freshwater species. It is found in the evaluated, unlisted hyperhialine estuaries in Sine-Saloum and Casamance

Citharinus citharus Endemic species of the Demersal anadromous species living under a tropical citharus Sudanian region but not climate evaluated, unlisted

Synodontis gambiensis Common endemic species of Benthopelagic freshwater species that lives under a West Africa but not tropical climate and that can be found in a shallow

Preliminary Plan for Freshwater Biodiversity Monitoring in the Gambia river basin Page 47 evaluated, unlisted sheltered environment

Barbus dialonensis Common endemic species of Benthopelagic species the West African region but not evaluated, unlisted

Barbus salessei Common endemic species of Benthopelagic species the West African region but not evaluated, unlisted

Clarias anguillaris Common species but Benthic habitats endangered by excessive fishing

Heterotis niloticus Common species in the Calm areas of large rivers, open lake and river waters Gambia basin

Barbus niokoloensis Endemic species of the West Benthopelagic species African region

Annexe 8 : Additional list:

Saretheroalon galileus

Heterobranchus longifilus

Malapterivus electricus

Labeo senegalensis

Mugil falciparum.

Preliminary Plan for Freshwater Biodiversity Monitoring in the Gambia river basin Page 48