There are many fishes that migrate from fresh water to salt water because of reproduction and food foraging needs. These fishes are consider the primary food sources even since antiquity and are considered the reason why human and other animals flock on rivers and stream to feed on migrating fishes that swim to shallow rivers to their nesting or feeding grounds. Because the streams and rivers that this fishes travel through are not their usual environment and because they travel in swarm, these fishes are easily captured on their up the stream. This migratory path is great sources of food for everyone that is why during these migration seasons many people do fly catching for sport or just bring their fishing net to bask on those traveling fish.
But because this is the time where fishes tries to reproduce, too much catching of fish can decrease the population of this migratory fishes overtime. There are many instances where a whole species of migratory fish vanishes because of over fishing, so to avoid the lost of those prize fishes, government and concern organization banded together to help save these fishes. They create seasonal fishing ban whenever they feel that their prize fish are being overfished. They also build water stream that serves as ladders to fishes which ease up their migration. They promote protection on the spawning ground of these fishes and allowing them safe haven from over fishing and harmful chemical spillage from factories that wanted to dump toxic waste to their precious stream. All of this functions and hard work create awareness of the vulnerability of these fishes and highlight the importance in keeping these special fish so that it can continuous to provide sustenance not just to the people but also to other species that feeds on them.