Hallo out there
To get my Masters Degree in Biology I am doing a litterature study in fish stock
enhancement, especially regarding problems after release and predation on the released
fish in particular.
Many species have been used in stock enhancement programmes where reared animals have
been released in nature. As far as I know, no fish stock enhancement programmes have
clearly shown to be succesful as judged by the number of repactured fish.
To find reasons for the lack of succes in stock enhancement, severel studies compaired
wild and reared fish concerning survival and a few studies looked at behavioural
performance in feeding and avoiding predators in wild versus reared fish.
And now to my request:
- Does any of you have information on the causes of reared fish having a lower survival
than wild fish?
If reared fish are incompetent with respect to feeding or avoiding predation - what is
then the reason? If these scills are inherited, reared fish should have the same
appropiate behavour as wild fish (at least if the breeding strain has been caught in
nature). But if fish must learn the right behaviour it is obvious why reared fish have a
lower survival. I know that the answer will probably differ among species, but I am
mainly interested in flatfish, gadids and salmonids.
- Does anybody know of studies where fish have been reared in a way that should promote
the "right" behaviour after release?
I have of course made searches in ASFA, but I could not find any recent papers dealing
with both stock enhancement and the developmental basis of behaviour.
Any information will be appreciated.
Tina Grønborg - thesis student
Univ. of Aarhus, Inst. of Biology, Dept. of Marine Ecology
Finlandsgade 14, DK-8000 Aarhus C, Denmark
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