By Michael Graham Richard, TreeHugger
There are around 440 known species of sharks!
There are many iconic species of sharks – the Great White in the film Jaws was burned into popular culture, for better and for worse – but they are still a very small subsection of the over 400 shark species that have been discovered by humans so far. Unfortunately, being overlooked by popular culture doesn’t give these lesser-known species any protection, and many of them are endangered. It is estimated that up to 100 million sharks are killed by people every year, due to commercial and recreational fishing. Meanwhile, the “average number of fatalities worldwide per year between 2001 and 2006 from unprovoked shark attacks is 4.3.” Kind of a skewed ratio, no?
In honor of Shark Week, I want to give you an overview of endangered shark species, some of which most people have never heard about – yet their role as top sea predators is just as important as any of the more photogenic species. Obviously we can’t cover all endangered sharks in one post, as there are simply too many, but we’ll try to show how much variety there is among sharks.
Note that some species are so rare now that it’s hard to find photos of them.
Angel Shark (Squatina squatina) – Critically Endangered
“Sources from the 19th and early 20th centuries indicate that the angelshark was once abundant all around the coasts of Western Europe. [...] Angelshark numbers have declined precipitously across most of its range; it is now believed to be extinct in the North Sea and most of the northern Mediterranean, and has become extremely rare elsewhere. During the comprehensive Mediterranean International Trawl Survey (MEDITS) program from 1995 to 1999, only two angelsharks were captured from 9,905 trawls.” (source)
Daggernose Shark (Isogomphodon oxyrhynchus) – Critically Endangered
The Daggernose shark lives in “shallow tropical waters off northeastern South America from Trinidad to northern Brazil, favoring muddy habitats such as mangroves, estuaries, and river mouths, though it is intolerant of fresh water. [...] The International Union for Conservation of Nature (IUCN) has assessed this species as Critically Endangered, as it has a limited distribution and is highly susceptible to overfishing due to its low reproductive rate. The daggernose shark has declined over 90% over the past decade off Brazil, and similar declines have likely also occurred elsewhere in its range as fishing pressure in the region continues to grow more intense. The IUCN has urgently recommended the implementation of conservation schemes and the expansion of fishery monitoring for this species.” (source)
Image Credit: Müller & Henle (Systematische Beschreibung der Plagiostomen pl. 15) [Public domain], via Wikimedia Commons
Zebra Shark (Stegostoma fasciatum or varium) – Vulnerable
The zebra shark is a species of carpet shark and the sole member of the family Stegostomatidae. It occurs in the tropical Indo-Pacific sea, frequenting coral reefs and sandy flats. “The World Conservation Union has assessed this species as Vulnerable worldwide, as it is taken by commercial fisheries across most of its range (except off Australia) for meat, fins, and liver oil. There is evidence that its numbers are dwindling.” (source)
Great White Shark (Carcharodon carcharias) – Vulnerable
Here’s an iconic one! It is also known as the great white, white pointer, white shark, or white death. It can be found in coastal waters in all oceans on the globe, and some individuals have been measured at 6 m (20 ft) in length and 2,268 kg (5,000 lb) in weight. “It is unclear how much a concurrent increase in fishing for great white sharks has caused the decline of great white shark populations from the 1970s to the present. No accurate population numbers are available, but the great white shark is now considered vulnerable. Sharks taken during the long interval between birth and sexual maturity never reproduce, preventing population recovery. The IUCN notes that very little is known about the actual status of the great white shark, but as it appears uncommon compared to other widely distributed species, it is considered vulnerable.” (source)
Shortfin Mako Shark (Isurus oxyrinchus) – Vulnerable
The Shortfin Mako is a fairly large species of shark. An average adult specimen will measure around 3.2 m (10 ft) in length and weigh from 60–135 kg (130–300 lb). The shortfin mako inhabits offshore temperate and tropical seas around the world. “In 2010, Greenpeace International added the shortfin mako shark (Isurus oxyrinchus or mackerel shark) to its seafood red list, ‘a list of fish that are commonly sold in supermarkets around the world, and which have a very high risk of being sourced from unsustainable fisheries.’ In 2010, the Convention on Migratory Species (CMS) also added the shortfin mako shark to Annex I of its Migratory Sharks MoU. This Memorandum of Understanding, currently in effect, serves to increase international understanding and coordination for the protection of certain migratory sharks.” (source)
Photo Credit: Mark Conlin, SWFSC Large Pelagics Program [Public domain], via Wikimedia Commons
Basking Shark (Cetorhinus maximus) – Vulnerable
The basking shark is the second largest living fish, after the whale shark (see next). “It is a cosmopolitan migratory species, found in all the world’s temperate oceans. It is a slow moving and generally harmless filter feeder and has anatomical adaptations to filter feeding, such as a greatly enlarged mouth and highly developed gill rakers. [...] It has long been a commercially important fish, as a source of food, shark fin, animal feed, and shark liver oil. Overexploitation has reduced its populations to the point that some have apparently disappeared and others need protection.” (source)
Dumb Gulper Shark (Centrophorus harrissoni) – Critically Endangered
The dumb gulper shark, Centrophorus harrissoni, is a rare and critically endangered deepwater dogfish, known from only along the east coast of Australia and isolated spots north and west of New Zealand. “It is also known as the dumb shark, Harrison’s deep-sea dogfish, or Harrison’s dogfish. The dumb gulper shark may grow to be 43 inches (110 cm) long and has a long, robust head, a long, flattened snout, large mouth and large, green eyes which help it see at 820 to 1260 feet (250 to 385 metres) under water.” (source)
Image Credit: A. R. Mc Culloch [Public domain], via Wikimedia Commons
Speartooth Shark (Glyphis glyphis) – Endangered
“The speartooth shark (Glyphis glyphis) is an extremely rare species of requiem shark, family Carcharhinidae. Only immature specimens, which inhabit the tidal reaches of large tropical rivers in northern Australia and New Guinea, are known. It is exclusively found in fast-moving, highly turbid waters over a wide range of salinities. [...] The range of conservation threats faced by the speartooth shark, coupled with its small population and restricted range and habitat preferences, have led the International Union for Conservation of Nature (IUCN) to assess it as Endangered. Furthermore, in Australia it has been listed as Critically Endangered on the 1999 Commonwealth Environment Protection and Biodiversity Conservation Act, though this is of minimal effect as Commonwealth protection does not apply until a distance of three nautical miles from the coast, likely outside the range of this shark.” (source)
Whale Shark (Rhincodon typus) – Vulnerable
“The whale shark is targeted by commercial fisheries in several areas where they seasonally aggregate. The population is unknown and the species is considered vulnerable by the IUCN. It is listed, along with 6 other species of shark, under the CMS Memorandum of Understanding (MoU) on the Conservation of Migratory Sharks. In 1998, the Philippines banned all fishing, selling, importing and exporting of whale sharks for commercial purposes, followed by India in May 2001, and Taiwan in May 2007. They are currently listed as a vulnerable species; however, they continue to be hunted in parts of Asia, such as Taiwan and the Philippines.” (source)
Here’s a video of a clever whale shark sucking fish out of a fishing net.
Photo Credit: FGBNMS/Eckert [Public domain], via Wikimedia Commons
Dusky Shark (Carcharhinus obscurus) – Near Threatened/Vulnerable
The dusky shark is a species of requiem shark that can be found in tropical and warm-temperate continental seas worldwide. One of the largest members of its genus, the dusky shark reaches 4.2 m (14 ft) in length and 347 kg (765 lb) in weight. “The International Union for Conservation of Nature (IUCN) has assessed this species as Near Threatened worldwide and Vulnerable in the northwestern Atlantic and the Gulf of Mexico. The American Fisheries Society has also assessed North American dusky shark populations as Vulnerable. Its very low reproductive rate renders the dusky shark extremely susceptible to overfishing. Stocks off the eastern United States are severely overfished; a 2006 stock assessment survey by the U.S. National Marine Fisheries Service (NMFS) showed that its population had dropped to 15–20% of 1970s levels.” (source)