Subject: Whales and Pollution

Steve Frohock (Sfrohock@tiac.net)
Wed, 30 Oct 1996 09:41:10 -0800 

The Taishoffs wrote:
> 
> Dear Steve,
>         How does pollution affect whales and other marine mammals?  What can we
> do to help this growing problem?
>         Thanks!

Dear Taishoffs,  Ocean pollution is probably the greatest danger that all 
sea creatures face today, not just whales. There are two separate ways 
that ocean pollution can affect whales, one short term and one long term. 
The short term problems arise from discarded plastic bags, six pack rings 
and even baloons. These can either entangle sea birds, sea turtles, seals 
or even small dolphins or kill them after they are mistaken for food and 
eaten.

The long term problems are more difficult to assess since it is difficult 
to sample whales swimming in the wild. Major causes of injury or death 
are disolved metals and non-soluble substances such as PCBs. This group 
of fat (not water) soluable compounds are collectively known as 
organohalides. Being only fat soluable, they are not diluted by sea water 
but rather tend to collect is fat resevoirs of zooplankton and small bait 
fish. This is what the baleen whales eat so the concentrations are passed 
along to the whale. Whales milk is extremely high in fat content to help 
the calves grow quickly so these toxins are passed directly from mother 
to calf during nursing. The levels of toxins that exist today are 
probably not lethal to the whales but the problem is the generational 
effect. This years calf will start out with the same toxin level as its' 
mother and will acquire additional toxins as it grows and feeds. This 
higher level will then be passed to the next generation through the milk, 
so it's a viscious cycle and no one really knows where it will eventually 
end. Some populations of smaller whales (beluga whales in the Gulf of St. 
Lawrence for example are already being decimated by PCBs. It is affecting 
their ability to produce healthy offspring and their fight infections. 
When one of these whales dies, it is carrying so many pollutants it has 
to be treated as toxic waste.

The problem trying to prevent these negative effects is very complex. 
Organohalides are produced by combustion of fossil fuels and industrial 
processes. They are also present in pesticides and herbicides. No one 
really knows where this is all leading. Products containing organohalides 
are common in many products we all use daily.

If you're interested in additional information try searching the web for 
"ocean pollution". I found about 500 sources from a search using 
Altavista (http://altavista.digital.com) and over 31,000 references 
searching with Lycos (http://lycos.com). As a start, the government has a 
site at http://seawifs.gsfc.gov/OCEAN_PLANET.

Good Luck,
Steve