Subject: Re: water pollution

Courtney E. Stirling (stirling@gsosun1.gso.uri.edu)
Wed, 27 Nov 1996 08:33:48 -0500 (EST)

Eric,
	Are you near a University library?  If so, I can give you some
references to look up that would be really helpful in answering these
questions.  I am not sure if papers have been published concerning habitat
shift due to food depletion.  However, what I had in mind was the shift in
humpbacks and finbacks from Stellwagen Bank up to Jeffrey's Ledge off the
US Northeast coast.  I worked at the New England Aquarium for two years. 
During that time I was a naturalist on their whale watch boat, making
daily trips to Stellwagen Bank - a well-known summering ground for
humpbacks, finbacks, and minkes.  For years these populations had spread
out north from Stellwagen, but a good portion of them still utilized
Stellwagen for most of the summer months.  In the summer of 1993 a
dramatic shift in location occured - VERY few of these whales were found
on Stellwagen, and most were farther north on Jeffrey's.  Again, I am not
sure if folks have decided what caused this but food shift was suggested
as one cause.  Another suggestion was that years of heavy boat traffic had
finally driven the whales to more quieter regions.  Either way, this shift
in summering grounds can be attributed to human interaction with some
aspect of the life history of these whale populations - whether it was
overfishing of the Stelwagen area that caused fish and krill to move
farther north, or heavy boat traffic which forced the whales to seek
quieter areas for their new calves to feed for the summer.	
	Now, about chemical pollution affecting whales...PJH Reindjers in
the Netherlands has been working to understand why the Baltic Seal
population crashed not too long ago.  What he has found out is that
chemical pollutants dramatically impacted the reproductive succcess of the
females in this population. What he has found is that some chemicals
have the ability to act like estrogen (one of the dominant hormones
controlling the female reproductive process in mammals).  When these
chemicals got into a seal they triggered other homrones and the
timing and strength of other hormonal signals was disturbed.   Similar
phenomenon are now being documented in whale populations in the St.
Lawrence River and elsewhere.  Again, if you could access scientific
journals at a nearby University that woul help greatly.  If not, I might be
able to fax one or two to you.  Let me know.
	Have a good Thanksgiving.

Courtney


On Tue, 26 Nov 1996, EJGAUDET wrote:

> Courtney, 
>              To clear up your question on whether I am a student or a
> teacher, I am a senior here at Sanborn.I felt that your return letter
> was full of alot of good information.If possible, I would like to learn
> more on the habitat shift and food depletion.Also I would also like to
> learn more on how chemical pollution is destroying the whales.
> 
> Thank You,
> 
> Eric
> Courtney E. Stirling wrote:
> > 
> > Eric,
> >         It would help me in answering your qustion if I knew if you were a
> > teacher or a student.  But, until then I will give you several
> > possibilities about how water pollution is affecting the lives of whales.
> > First, it is important to define pollution.  I will use a definition that
> > includes habitat disruption, like overfishing, as well as traditional
> > pollution types, like plastics and chemicals.
> >         Overfishing is a relatively new thing in the oceans.  A good
> > example of bad management of fisheries is George's Bank.  This is a prime
> > region for summer feeding and calf rearing for the western North Atlantic
> > humpback population.  In the past five years summering populations have
> > shifted to other areas of the western North Atlantic.  So, habitat shift
> > and possible food depletion are two effects of pollution - directly
> > impacting whales.
> >         More classical pollutants like oil spills, plastics and
> > chemical runoff from farms and agriculture operations effect whales
> > negatively also.  It is well known now that coastal cetacean populations,
> > individuals of these populations more specifically, can choke on plastics
> > or become entwined in loose fishing nets - causing death in extreme cases
> > and swimming impairment otherwise.  Chemicals are a particular threat to
> > whales because many of the agro-chemicals in use (and no longer in use in
> > the US, DDT) are lipophilic and accumulate in the blubber of cetaceans.
> > Reproductive disorders, genetic damage, and immune-suppression result from
> > long-term accumulation of these compounds.
> >         SO, this is an overview of some of the pollution problems facing
> > whales.  Please let me know which of these issues interests you most and I
> > can get you some references.
> > 
> > Sincerely,
> > 
> > Courtney
> > 
> > On Thu, 21 Nov 1996, EJGAUDET wrote:
> > 
> > > Hello,my name is Eric.I am in an Environmental Science class,here at
> > > Sanborn Regional High School.I am writing to you as my project.I am to
> > > establish an email communication with an environmental scientist.I must
> > > mantain this communication about my essential question for at least 10
> > > communications.My question is: How is water pollution effecting the
> > > lives of whales?
> > > Thank You,
> > > Eric
> > > --
> > > E.J. Gaudet- teacher
> > > Project Whaleboat
> > > Sanborn Regional High School
> 
> -- 
> E.J. Gaudet
> Project Whaleboat
> Sanborn Regional High School
> http://sanborn.k12.nh.us