By: Dr. Camila C\u00e1ceres, Dr. Val Sch\u00fcll, Kristin Butler<\/p>\n\n\n\n
Sharks have been around for almost 450 million years, before trees evolved on Earth and longer than Saturn has had its rings. Sharks are an incredibly diverse group of fish, with over 500 different species ranging from 8 inches in length (the dwarf lantern shark) to 60 feet (the whale shark, the largest fish in the ocean). Sharks live in a wide variety of habitats, from coral reefs to deep pelagic waters and even freshwater ecosystems. However, despite sharks\u2019 ancient history, powerful adaptations, and numerous species, in recent decades global shark (and ray) populations have declined by an estimated 71%<\/a>, primarily due to overfishing (catching too many sharks) and bycatch (when sharks are unintentionally caught by fishers and their gear). The slow reproductive rates of sharks hinder their ability to rebound from these pressures, resulting in the risk of extinction for numerous species and possible disruption of marine ecosystems.<\/p>\n\n\n\n Given the important role many shark species play in ocean ecosystems, such as maintaining biodiversity, regulating marine populations, nutrient transport, and supporting coral reef health, scientists and conservationists have been working diligently to protect sharks. The Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES)<\/a> has expanded its protections for sharks globally, NOAA has banned shark finning in the Atlantic Ocean, and several shark species have been added to the list of Endangered Species Act in the U.S. <\/p>\n\n\n\n Due to these recent conservation efforts, some shark populations have started to recover in a few regions in the U.S. Florida, North Carolina, California and Hawai\u2019i are some notable places that have reported a diversity of shark species and improved numbers in recent years, yet there are mixed responses from the community regarding healthier shark populations. Fishers are reporting losing their catch (like tuna, snapper, grouper, etc.) to sharks when sharks bite, or completely take, the fish off the line. This term has been coined depredation<\/em>, the act of a shark removing or damaging a fish hooked by a fisher before it can be landed. Depredation results in the loss of catch and\/or gear, causing frustration among fishers and potentially jeopardizing fish populations if fishing pressure for target species increases in response to depredation.<\/p>\n\n\n\n