Hehe
The issue with releasing Large, strong and healthy fish is a genepool one and really significant to the policy of quality vs quantity. Lets say theoretically, there was a need that called for all males above 6ft and 200lb well built, say a war in a small isolated island. Say they all die lol, and there are only shorter and smaller people to continue to populate it, the results would be as we know- generally and eventually the average height and weight would fall for fully mature adults, providing the war demands steady manpower over the years as big" genes decline in frequency.
While certain fish species are migratory, generally, local populations tend to stick in an area that can support them and breed in particular spots that are favourable to spawning. This reduces the chance of external genes from entering the population.
When you catch large, old and prominent breeding fish in an area at a steady rate over a long period of time, you end up with a severe lack of pretty much 'big fish genes'. Its survival of the fittest in the natural world and the most fit specimens are always going to be the ones that out compete others to pass on their genes. When smaller individuals are thrown back while monsters are harvested, you have a population with fully mature individuals that are much much smaller passing on their genes. So while conservation efforts may lead to you having a larger amount of fish stock(Quantity), the overall stock will be composed of smaller fish(Quality). This doesn't happen short term but over many many years of bad fishing habits like that.
Examples like haddock that has been pushing 15 years of conservation shows little improvement in quality of stock because of the initial damage. A local thing I could point out is waliacke, the average size of a redfish caught 10 years ago and now is chalk and cheese, chaguaramas still loaded with them but whereas a 3lb fish was a normal occurrence, now its a trophy. Locally I think people just catch and take every and anything lol.
