Imagine we lived in a world where future generations never know what dolphins, whales, and sea turtles are. This may be possible if unsustainable practices of fishing continue. The major issue at hand is catching non-target animals, also known as bycatch. This is a significant problem in the U.S. that wastes the ocean's living marine resources.
Bycatch occurs because modern fishing gear is efficient and highly unselective, meaning it not only catches the target species, but catches many other marine animals. Some modern and most common methods of fishing gear include longlines, trawling and the use of gillnets. Animals get caught in that gear and try to fight their way out of it to the point of exhaustion, eventually not being able to fight anymore and die. Some other ways that animals are killed from bycatch re if the gear is in their mouths, impeding their ability to feed or if the gear cuts into their flesh because they continue to grow with the gear around them.
Another issue that comes along with bycatch is 'ghost fishing'. This is when the non-selective gear is lost at sea, torn away, or simply abandoned and becomes 'ghost gear'. Generally, the gear is never recovered and can continue to capture marine animals for years. The gear first floats around, collecting a plethora of species. It will eventually sink from the weight of all the organisms. The biomass eventually breaks apart in the ocean's benthic regions, lightening the gear again and allowing it to float on top of the water. It is a neverending cycle. It is estimated that there are 640,000 tons of gear is getting lost in the ocean.
Some impacts of bycatch are that many species that are caught and are non-target species are either endangered or threatened species already. It is estimated that 300,000 small whales, porpoises, and dolphins die from entanglement in fishing nets each year. Hundreds of endangered loggerhead turtles and critically endangered turtles are drowned yearly. You would think that the environmental changes would be a major threat to these animals, but in reality, humans are the biggest threat.
There are some solutions that do exist to reduce bycatch. Some include alternative gear. For example, instead of using j-hooks on longlines, the fishing industry can use "circle hooks." These are less likely to be swallowed by turtles and would not cause as much damage if ingested. Also, better regulation of disposal of gear could be done to prevent ghost fishing. Research and improvements in gear continue and will hopefully diminish bycatch.
