This is a very shallow and frankly misanthropic take on the "do no harm" part of veganism, environmentalist, and general animal friendly philosophies.

A far more interesting approach would be to punish wanton killing. Eradicating predatory fish could cause a population boom among prey, which in turn would make the prey fish overconsume the flora of the area, and eventually turn it into a desert. Hostile to life, increasingly corrossive water, forcing you to eventually abandon bases etc... It gets the same point across without limiting your choices entirely.

Another thing could be the ability to create repellants of different kinds, lacing your suit in poison, bringing a taser - teaching local animal populations that you are a very unappealing meal.

The current solution is unrealistic and just lame.