There is so much to celebrate about these incredible, diverse apex predators; one week doesn’t seem like enough. Sharks belong to a group of animals called elasmobranchs, which also include skates and rays. Evolutionarily speaking, sharks are some of the world’s most successful animals. Their ancestors first evolved have been around for 400 million years, 100 million years before dinosaurs first made an appearance on Earth and hundreds of millions of years before the first humans arrived.

Sharks and Rays, Shark week, Vancouver Aquarium

Sharks and rays have a lot in common. See them both at the Aquarium.

Humans, however, are having an alarmingly negative effect on shark populations worldwide. Sharks currently represent the largest group of marine species on the International Union for Conservation of Nature (IUCN) threatened list with approximately 100 million sharks killed per year.1   Scientists estimate that 25 species of sharks will go extinct during our lifetime.2 The shark fin fishery accounts for approximately 30 per cent of annual shark deaths. Bycatch is responsible for 60 per cent each year.

Shark bycatch

Shark by catch accounts for 60% of shark deaths each year. Photo credit: Fiona Ayerst, Marine Photobank

Pelagic longlines are used to catch open-water, migratory fish species such as tuna. They consist of a fishing line floated close to the surface of the water with buoys from which thousands of baited hooks dangle and can stretch up to 150 km long; that’s more than the distance from Vancouver to Whistler! Pelagic longlines entangle and kill a variety of non-target species, many of which are threatened, such as sharks.

Finned shark

Finned Shark Pacific Photo Credit: Wolcott Henry 2005 Marine Photobank

In the Gulf of Mexico and the Pacific Ocean, for every two yellowfin tuna caught, one shark is caught as bycatch.3 Similarly, in the Atlantic Ocean, for every swordfish caught using longlines, two to three sharks are caught as bycatch.4 Since sharks are slow to reach reproductive maturity and produce few offspring, the combination of targeted and non-targeted fishing are causing a drastic decline in shark populations.

Why should we care if sharks become extinct? Are they not dangerous predators, making the ocean a scary place to venture into? On average, only four humans are killed every year by sharks, compared to the 100 million sharks that humans kill each year. Most importantly, sharks are apex predators which are critical to the functioning of an ecosystem. When shark populations decline, ecosystems are thrown off balance and other species are also negatively affected.

Fortunately, there are ways that we can help. You can choose not to consume shark products such as shark fin soup. If the demand goes away, so will the finning. According to a recent report by WildAid, demand for shark fin soup has fallen by 50-70 per cent. Look for seafood identified with our Ocean Wise symbol, this is the Vancouver Aquarium’s assurance that the seafood item was caught in a sustainable way and that the species is abundant and well-managed. An excellent shark-friendly seafood option is albacore tuna caught by pole. Who says you can’t eat your tuna and save the sharks too? Happy Shark Week everyone!

 

 

References:

  1. Worm, B., Davis, B., Kettemer, L., Ward-Paige, C.A., Chapman, D., Heithaus, M.R., Kessel, S.T., Gruber, S.H. 2013. Global catches, exploitation rates, and rebuilding options for sharks. Marine Policy. 40: 194-204.
  2. IUCN 2010.
  3. Baum, J.K. and Myers, R.A. 2004. Shifting baselines and the decline of pelagic sharks in the Gulf of Mexico. Ecol. Lett. 7: 135-145.
  4. Brodie, P. and Beck, B. 1983. Predation by sharks on the grey seal (Haliochoerus grypus) in Eastern Canada. Can. J. Fish. Aquat. Sci. 40: 267-271.

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2 Responses

  1. Tara

    It would be Great if the Aquarium could get Rob Stewart of Sharkwater to come and host an event – he has raised so much awareness in the importance of sharks and how we can save them. To know that sharks have survived the longest and have now become in danger of existing is so unfortunate. These magnificant creatures of our oceans deserve our support. While “Jaws” in 1975 might have made some leary, it made me fascinated with sharks since!!

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