Page - May 27, 2009

Greenpeace Canada Redlist

Fishery Facts

Common and Latin Names Spurdog Squalus acanthias (Piked dogfish, Spiny dogfish), porbeagle shark Lamna nasus, shortfin mako shark Isurus oxyrinchus.

Fishing Method Longline, gillnet, and bottom trawl.

Region of Harvest There is a targeted fishery for porbeagle and spurdog off of Canada's Atlantic coast, while shortfin mako is caught mainly as bycatch; spurdog is also targeted off the Pacific coast. Generally these sharks are all widely distributed in the world's oceans.

Why is it on the red list?   Biology

1. Sharks are overfished, and there has been a drastic decline in shark populations to an estimated 10 per cent of biomass since the beginning of industrial fishing. Porbeagle is listed as vulnerable on the IUCN red list. Shortfin mako is designated as threatened under COSEWIC

2. Half of all the sharks killed each year are caught accidentally in fishing gear intended for other fish. Some shark species are caught by illegal (pirate) fishing. Bycatch is the primary cause of death for shortfin mako in the North Atlantic.

3. Sharks are caught by a variety of destructive fishing methods such as longlining and bottom trawling. These methods are associated with high unintentional catch (bycatch) of other fish species, as well as endangered turtles, marine mammals, and seabirds.

Spurdog is the smallest and longest living of these three species, living up to 75 years.

Shortfin mako is the largest, growing up to four metres and weighing up to 500 kilograms.

Sharks feed on fish, rays, cephalopods, octopuses, cetaceans and various other species depending on size.

Sharks species have an internal skeleton of flexible cartilage making them very agile hunters.

Sharks have highly evolved and complex brains, giving them a superior sense of smell, taste and sight to many other marine animals.

Sharks have a very low resilience to population pressures as they are slow reproducers.


Sharks are increasingly caught for their fins to make shark-fin soup, a delicacy in some cultures. In this fishery it is common to cut off the fins of the shark and discard its carcass. The practice of 'finning' was banned in Canada in 1994.