6 posts • Page 1 of 1
This topic is somehow in between ecology, physiology and zoology, if the moderators think it should be moved please go ahead. I post it here because I think it might be the most appropriate location.
I've been thinking about possible solutions to determine if a fish caught in a private pond comes from a fish farm or from public waters.
The only feasible thing I could come up so far was to use stable isotopes on the scales to check if the fish was raised on highly nutrient pellets in a hatchery and then switched to normal (less nutrient rich) sources.
Analyzing different areas of the scale I should be able to do that.
But it wouldn't apply to such fish as carp, for example, since bait used in private ponds recreational fisheries is nutritionally very similar to fish farming pellets.
Assuming that the fish is transported from public freshwaters to private freshwaters I cannot use salinity variations as markers. If the fish is illegally transported it's not possible to use any legal essay since there wouldn't be a definite documentation of the stocking.
I thought about a possible difference in pollution levels between public and private waters assuming that high concentrations of pollutants such as heavy metals are present in the first but absent in the latter.
It still would require a costly and lenghty preparation and analysis but it should be feasible.
I found a reference from a private agency that involves chemically testing anatomical parts of the fish (carp) and water quality but they won't disclose further details (for commercial reasons I suppose). It seems that the methos is non invasive, cheap and simple to use. Do you think such a method is feasible? If so what do you think it involves exactly?
More in general, how would you solve the problem at hand?
Well for example it could be useful to determine if a private lake has had any illegal stocking in the last few years. In many countries of Europe transport of fish from public to private waters is forbidden and prices for black market fish up to 10.000$ per individual.
Using genetics would be easy but requires you to make a quite complete mapping of populations both in the wild and hatcheries to compare your samples.
Any comments on the methods I thought of?
your idea could work, you would just need to measure pollutant level in both waters and check some fishes from both sources (best double blind test) and see, whether is there significant difference.
Cis or trans? That's what matters.
I would love to quote this
...in the Philippines it takes such a long process and a difficult one. Sometimes bacteria still comes a long and salinated water so to make sure its all clear and safe they put so much chlorine that sometimes causes chemical poisoning.....
6 posts • Page 1 of 1
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