The idea is awesome, but...
(https://i.imgur.com/KGUG5O4.jpg)
I've seen that you suggest that we should fish sharks in a possible update (if you don't believe me, open the spoiler). Why would we do that? First of all, I don't think people can really see sharks in New York in real life, so why would there be sharks in Liberty City (museums and aquariums are not included in the discussion)? Second of all, it is really cruel and simply doesn't bring us any real good in real life. Did you know that sharks are searched for their fins and many times left without them to die in the ocean (https://en.wikipedia.org/wiki/Shark_finning)? Only for a soup! (http://www.stopsharkfinning.net/what-is-shark-finning/)
In rest, if we roleplay that we release them in the ocean, it should not be a problem (https://www.theonlinefisherman.com/shark).
Anyway, it would be nice if we could fish the species striped bass (https://en.wikipedia.org/wiki/Striped_bass), since they aren't in any danger of extinction and can reach up to 31 kg in adulthood, but they usually weight at around 4.5-14.5 kg.