1. Description of the selected reservoirs
The original workplan describes the selection of reservoirs as follows:
| Owner | Water level status |
| Community | full all year |
| Community | fluctuation level |
| Community | drying up |
| Government | full all year |
| Government | fluctuating |
| Private | drying up |
Description of each reservoir should include:
2. Physico-chemical water sampling (monthly starting in Feb 95)
According to the workplan the following samples should be taken monthly: water level, surface area, depth, temperature and oxygen profiles, pH, alkalinity, Chlorophyll a, and total phosphorus. Secchi Disk depth, TDS, conductivity, total hardness and Nitrate-N were added to this list from the beginning of the sampling. Total phosphorus was replaced by Phospate-P. Surface area estimation is done only quarterly for practical reasons (time-consuming)
All parameters are analysed for only one sampling site per dam, normally the deepest spot.
| Parameter | time | depth | method | Reference |
| DO | 5 am & 5–6 pm | profile: every m | DO-meter | WTW |
| Temp | 5 am & 5–6 pm | profile: every m | DO-meter | WTW |
| pH | morning | surface | pH-meter or colorim. | HACH |
| Alkalinity | morning | surface | digital titration | HACH |
| Hardness | morning | surface | digital titration | HACH |
| Nitrate-N | morning | surface | Colorimetric | HACH |
| Phosphate-P | morning | surface | Colorimetric | HACH |
| Conductivity | morning | surface | Conductivity-meter | HACH |
| Secchi Disk depth | morning | NA | genuine Secchi Disk | SM of water analysis |
| Chlorophyll a | morning | surface | filtration 3μ | SM of water analysis |
| Water level | NA | NA | benchmark | |
| Surface area | NA | NA |
Profiles are carried out with a probe on a long cables for DO.
3. Biological sampling (bi-monthly starting in Feb 95))
According to the workplan the following samples should be taken monthly: fish gonad development, fecundity (for determination of period of reproduction), seasonal information on length frequency data of selected species (collected using beachseines for small reservoirs and in combination with gill nets for larger reservoirs). Based on practical considerations however, only physico-chemical sampling is carried out monthly and only beach seines are used since no big reservoirs were included.
3.1. Fishing method
A seine net is pulled 3 times on 3 different places in the reservoir. The seine is 125m long, 6m high and has 1 inch stretched mesh size. The surface of the pull is estimated and indicated on the map (either on the descriptive base map or on a new map if changed) as well as the time. The whole catch of the pull is sorted by species and put in separate hapas.
Necessary equipment:
| equipment | number | type |
| boat | 1 | big enough for the seine net |
| seine net | 1 | 125m × 6m, with pocket and mesh size 1" stretched |
| dipnets | 3 | mesh size minimum 1" |
| buckets | 6 | 10 liter |
| basins | 6 | 100 liter |
| baskets | 6 | fitting in 100 liter basins, mesh less that 0.5 inch |
| hapas | 6 | volume 1–2 m3 and mesh size less or equal to 1" |
3.2 Length Frequency data
A sample of approximately 300 individuals per species is taken at random with a scoopnet from the hapas. Standard length is taken for every fish and noted by ticks with a precision of 5 mm. Normally two people are measuring, one is ticking. All fish is kept alive in baskets inside the basins and has to be put back in the reservoir except for the GSI samples.
Necessary equipment:
| equipment | number | type |
| measuring board | 1 | precision 1mm. |
| ticking form | 1/species/pull | 5mm per line |
3.3. Catch and effort analysis
All the fishes from the pull are counted and batch-weighed per species. Weight is noted to a precision of 100 g. After weighing the fish is put back in other hapas until final seining is finished. If this is not possible fish is put back on the same place in the reservoir to avoid recapture by the next seining. If the owner of the reservoir wishes to harvest some of the fish, the species, number and weight of the harvested fish is noted
Necessary equipment:
| equipment | number | type |
| basket | 6 | fitting in basins of 100liter, mesh < 0.5 inch |
| hanging balance | 1 | “milkscale”: capacity 25 kgs, precision 100 g |
3.4. GSI
A sample of 5 females and 5 males per species is taken from every pull to determine TL, SL, weight, gonad weight and gonad status no. The sample is taken to represent all sizes between estimated size of non-developed gonads and the biggest size found. Fish are measured on a measuring board with 1 mm precision and weighed with 1 g precision. Gonads are dissected and weighted with a precision of 0.1 g.
Necessary equipment:
| equipment | number | type |
| measuring board | 1 | precision 1mm, |
| dissection eq. | 1 | pair of scissors |
| scale | 1 | cap. 2–4 kgs, precision of 1g |
| precision scale | 1 | cap. 100–300g, precision of 0.1g |
3.5. Other biological data
The presence and abundance should be noted of species of:
