Whales/Polution

From: Kim Marshall (kimm@oceanalliance.org)
Date: Fri Mar 24 2000 - 12:25:54 EST


Question: We have a project in Biology at the moment - "Save the
>Whale". I would like to know what impact polution as such have on
>whales. Any other info concerning "Save the Whale" would be welcome.
>
>Reply: Dear Raoul:
This is quite an extensive answer and I suggest that you do some research
on your own about this subject.

The chemical revolution of the latter half of the 20th century has created
a multitude of new products, many of which are highly toxic, or are
accompanied by highly toxic by-products which when concentrated are nearly
immortal poisons. Among the most dangerous of these are the
organochlorines - a family of compounds that includes PCBs, dioxins,
furans, PAHs, etc.. When organochlorines get into the oceans (via run off,
dumping and atmospheric pollution), they settle in the fats of minute
plants and animals, becoming more concentrated as they move up food
pyramids supported by those planktonic organisms. The larger fish in such
pyramids are eaten by whales and people, often resulting in concentrations
of organochlorines in their tissues millions of times higher than those
found in plants at the base of the pyramid. A very serious threat to
humans and wildlife is that several of these toxins mimic female hormones,
causing developmental problems. Accumulating evidence suggests that these
substances may be responsible for such increasingly observed conditions as
lowered sperm counts in men, malformed reproductive organs in both sexes,
developmental problems in fetuses, learning disabilities in children, and
increasingly compromised immune systems in all mammals. As such they may
represent one of the gravest threats to the human future.

Mammalian mothers unwittingly pass their accumulated organochlorines to
their fetuses in their blood and to their newborns in their milk. So
instead of starting life as pristine creatures, wild mammals start with
roughly their mother's concentrations of organochlorines. In this way, the
organochlorine concentrations increase with each generation, inexorably
reducing the overall fitness of animals that live high on oceanic food
pyramids. Some government agencies already advise against eating large,
mature fish of fatty species since they have had longer to accumulate
organochlorines. Many ocean fisheries may become inaccessible to humans if
concentrations of organochlorines keep increasing and the concentrations of
contaminants in fish become too high. Despite such dire possibilities,
neither the overall distribution nor the concentrations of these substances
in the world's oceans are known. Both factors must be known before nations
are likely to become concerned enough to take action to prevent further
pollution of the seas.

Whale Conservation Institute/Ocean Alliance
191 Weston Road, Lincoln, MA
(781) 259-0423
www.oceanalliance.org



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