Fish fingerlings are small (20mm - 60mm) when they are in the nursery pond. I have read about mark-release technique/method but I doubt if it is practical.
Can anyone provide me with practical sampling methods to estimate fish fingerling quantity in a 300~1000ton nursery pond? e.g. how to catch the fingerlings, which part of the pond should I approach first.
Thank you!
Dear Kelvin Chai
choose four random areas and be equal space, surround these four areas nets with small holes and are fishing in each specific area and extracted the number of fish in each area and then extracts the number of fish rate of four areas on the basis of unit area and then extracted the total number of the pond.
Best regards
S J Muhammed
Dear Kelvin,
The satisfactory estimation of quantity of such small-size fish fingerings in a 300~1000ton nursery ponds (enough large ponds) can be achieved only by complete emptying (discharging) and manual (automatic) counting of fishes. I think suggested by Mr. Sadiq method can be applied only in cases with not swarm-building fish species. Because swarm-building fish fingerlings are distributed unevenly in the pond, they gathering in most comfortable places of the pond (e.g. feeding places) and most of parts of the pond are left empty from fish. I suggest using for your experiments controllable pond where you can almost fully empty your pond and count the fish. As a rule during the fingerlings raising you have to conduct periodical control catches of about 100 fishes in order to make corrections to feeding rate and to observe other fish growth indicators.
IN general I advise you to use smaller glass containers (up to 2-3 m3) to conduct such experiments.
With best wishes Bakhtiyor
Thank you very much for your guidance, Mr. Sadiq Jawad Muhammed and Mr. Bakhtiyor Karimov. I will try Mr. Sadiq's method first as I hope this experiment can help hatchery and nursery operators in estimating the SVR.
There are several methods. You mentioned the fish marking. In Japan albino fingerlings (bright yellow) have been added to tanks of trout to provide an estimate. Add the fish, let them mix, then count ratios in a dip net.
Another way which mimics the experience of hatchery managers who can look at a tank and tell roughly how many fish are there, is to vertically photograph the top (or horizontally the side) of the tank and count those fish in the photo. Do that 10-15 times and you have a series of "samples" from which you can make an estimate.
- Badges
- Science method
- Similar topics
- Biological Science
- Ecology