Saltwater Fish

Saltwater fish, also called marine fish, are fish that live in ocean water. Saltwater fish can swim and live alone or in a large group called a school.^[1]

Saltwater fish are very commonly kept in aquariums for entertainment. Many saltwater fish are also caught to be eaten,^[2][3] or grown in aquaculture. However, many fish species have been overfished and are otherwise threatened by marine pollution or ecological changes caused by climate change.

Overfishing is defined as the mass removal of fish from a body of water that results in halting the ability for breeding populations to replenish what has been removed. Fish is one of the most popular foods in the world and consumption has continued to rise with the growing human population and will continue to do so. The value of the global seafood market has seen a 15% increase from 2016 to 2020 and is projected to increase even more by 2023.^[7] Although it provides many people with a source of food, the global seafood market is a major threat to the biodiversity of fishes. Bycatch is a direct effect of overfishing and is defined as the unwanted capture of different marine organisms during industrial fishing. This results in many different species of fish dying after they are captured and discarded. Data on bycatch is often unclear and not well recorded but it is estimated that the U.S. alone discards 17-22% of their catch annually.^[8] The Mesopredator release hypothesis is one of the indirect effects of overfishing that is also often referred to as "fishing down the food web". This phenomenon means as fisheries deplete large apex predatory species, mid-sized predatory species increase in abundance and assume the role as top predators on the food web.^[9] This impacts the food web in marine environments and disrupts the balance of the ecosystem and is likely to cause trophic cascades.