Why are we only allowed to catch fish over a certain size?

Fish are only allowed to be caught over a certain size to ensure that they have a chance to reproduce. When fish are too small, they have not yet reached sexual maturity and are not able to reproduce. By setting a minimum size limit, it helps to ensure that there are enough fish left in the water to maintain a healthy population. Additionally, larger fish are generally considered to be more valuable and desirable than smaller fish, so setting a minimum size limit can also help to increase the overall economic value of the fish catch.