Porbeagle Shark


Porbeagle Shark
Lamna nasus

    Opportunity for public comment on the proposed addition of Porbeagle Shark to the List of Wildlife Species At Risk in the Species At Risk Act. Porbeagle shark was recently assessed by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) as "Endangered" and is currently being considered for legal listing on Schedule 1 of the Species At Risk Act (SARA). Once listed, porbeagle shark will be protected under SARA. This protection includes, but is not limited to, the proviso that no one "shall kill, harm, harass, capture, or take" any of these individuals.

   A consultation workbook, including a survey with questions related to the conservation and recovery of this species, has been developed. To request a consultation workbook or a meeting to discuss the proposed listing and its consequences, please contact:

The Species At Risk Coordination Office
Tel: 1-866-891-0771
E-mail: XMARSARA@mar.dfo-mpo.gc.ca

   To complete an electronic version of this survey, visit the website: http://www.sararegistry.gc.ca/public/default_e.cfm

    A public consultation has been scheduled for the following: Thursday, March 10 - Holiday Inn Select, Halifax, Nova Scotia 7 pm - 9 pm (bilingual session)
   Your input is important. Comments received will be considered in the listing process.
   More information on Species At Risk can be found on the SARA Public Registry at www.sararegistry gc.ca.

Shark Conservation

   Humans have hunted sharks for sport, food, medicine, and leather for centuries, with little regard for the health of shark populations. Sports fishers around the world regard sharks as some of the most challenging fish to catch in the sea. Shark flesh is highly prized in many regions of the world. One particularly popular food made from shark meat, shark fin soup, is in such demand that some fishers hunt sharks just for their fins, throwing the rest of the fish back to the sea to die. Shark liver oil is a popular source of vitamin A, and some people believe that shark liver and cartilage are beneficial to human health. Shark skin, with its microscopic teethlike scales, was once used as a fine grade of sandpaper, and when the scales are removed from the skin to make shark leather, it brings high prices for use in shoes, belts, and handbags. Many sharks are killed unintentionally. Each year, thousands of sharks die in nets set out to catch other types of fish. Sometimes, humans kill sharks just because they fear them.
   Such activities have placed many shark populations in danger of extinction. For example, between the mid-1980s and mid-1990s, populations of dusky sharks and sandbar sharks off the eastern coast of the United States declined by more than 80 percent. Internationally, the sand tiger shark and the great white shark are also in danger of extinction. Sharks grow slowly, reproduce late in their lives, and produce few offspring when they mate, making the natural rate of population replenishment very slow. If too many sharks in a particular area are killed, that population may never recover. For example, numbers of porbeagle sharks, swift, ocean-going sharks once commercially valuable, declined dramatically until, by 1960, commercial fishers could no longer catch enough of them to cover their expenses. Thirty years later, porbeagle populations still have not recovered.
   As researchers begin to better understand the devastation human activities have brought to many shark populations, they also better understand the benefits sharks provide. Losing these top-level predators produces devastating effects to local ecosystems. Moreover, medical researchers are interested in learning more about sharks, particularly their immune systems. Sharks recover rapidly from severe injuries. They appear to be nearly impervious to infection, cancers, and circulatory diseases. For decades some people have believed that shark cartilage has anticancer properties. Although recent scientific studies challenge this belief, medical researchers continue to investigate the shark immune system in hopes of one day applying its secrets to fight human disease.
   To prevent the effects of overfishing and other human activities in the United States, state and federal management plans restrict the number of sharks that can be legally killed. Plans also require that fishers take entire sharks, instead of just the fins, preventing the practice of cutting off the fins and leaving the rest of the fish to waste. In many countries, including South Africa, Australia, and the United States, legislation specifically protects great white sharks, a species widely prized as a game fish and considered to be endangered in many areas where they once roamed in large numbers.
   While nets around bathing beaches prevent sharks from entering popular waters, such nets claim the lives of thousands of sharks each year. More sophisticated methods to repel sharks are under investigation. Chemical substances similar to fish toxins have been developed, and the repellent effects of many detergents may offer a chemical means to deter shark attacks. Electrical devices that interfere with shark sensory systems may one day offer another alternative to nets.

"Shark," Microsoft® Encarta® Online Encyclopedia 2001 © 1997-2001 Microsoft Corporation. All rights reserved.
Contributed By: Jeffrey C. Carrier, B.S., M.S., Ph.D. Professor of Biology, Albion College.