|
|

Porbeagle
Shark Lamna nasus
PUBLIC NOTICE: 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
http://encarta.msn.com ©
1997-2001 Microsoft Corporation. All rights reserved. Contributed By:
Jeffrey C. Carrier, B.S., M.S., Ph.D. Professor of Biology, Albion College.
©WebWise
Inc. |