The Impact of overfishing
Many of the fish that we so enjoy consuming are also the most sought after. Often times, such fish are caught before they are capable of reproduction. In conjunction with rapid, modern-day fishing practices, this has resulted in their numbers having been greatly depleted. As you can guess, yearly fishing yields of around 80 million metric tons aren't exactly too kind to the world's fish populations. Rebuilding such fish populations becomes hard when it is nearly impossible for significant reproduction to occur. An important thing to note is that a lot of these fish exist as top predators in their ecosystems, and when these species begin to disappear from their respective food webs, ecosystems begin to change. Food webs experience great shifts. Lower trophic level, smaller fish begin to replace the predators at the top. Due to their lower trophic level status, more of these fish are needed to provide the same amount of energy to a consumer that fewer top predator species could produce. As a result, larger numbers of these smaller fish are needed, and even more overfishing begins to occur.
A large part of the impact of overfishing comes from the actual methods of fishing. In most methods of commercial fishing, bycatch, any marine organism that is caught along incidentally with commercial species, is the main problem. Bycatch is estimated to account for over a fourth of the world's total marine catch, yet the majority of these organisms either die or are dying before being thrown back into the ocean. This has lead to the endangering of a significant number of the species that end up as bycatch and is just plain wasteful. Perhaps one of the most destructive forms of fishing is shrimp trawling, which involves nets with weighted trawl doors being dragged across the ocean bed. It has been responsible for such destruction of numerous seabed communities that this method has been likened to the clearing of forests. It is also responsible for around a third of the world's total bycatch. Other methods of commercial fishing include the use of drift nets, purse seining, dredging, and other types of trawling. Some of the methods of commercial fishing such as trolling or jigging are much more effective than others in reducing the amount of bycatch that comes aboard.
A large part of the impact of overfishing comes from the actual methods of fishing. In most methods of commercial fishing, bycatch, any marine organism that is caught along incidentally with commercial species, is the main problem. Bycatch is estimated to account for over a fourth of the world's total marine catch, yet the majority of these organisms either die or are dying before being thrown back into the ocean. This has lead to the endangering of a significant number of the species that end up as bycatch and is just plain wasteful. Perhaps one of the most destructive forms of fishing is shrimp trawling, which involves nets with weighted trawl doors being dragged across the ocean bed. It has been responsible for such destruction of numerous seabed communities that this method has been likened to the clearing of forests. It is also responsible for around a third of the world's total bycatch. Other methods of commercial fishing include the use of drift nets, purse seining, dredging, and other types of trawling. Some of the methods of commercial fishing such as trolling or jigging are much more effective than others in reducing the amount of bycatch that comes aboard.