Subject: Plankton

Lindsay J Porter (
Wed, 24 Jun 1998 11:37:12 +0800 (HKT)

>Whales consumes tons of plankton plus other various food during normal
>feeding times. My question is that if we lose the whales due to mass
>killings by various nations would this have a great effect on the amount
>of plankton not readily comsumed by whales cause a over abundance of
>plankton. Wouldn't this cause some parts of our oceans to become thick
>with plankton?

Dear John,
Many apologies but I am unsure what the answer to this question is.  My
understanding is that the plankton themselves are under some pressure from
fisheries, other apex predators (seals/sea lions) and pollution.  In
addition I came across this article in WhaleNet while trying to search for
more information on your question.

Sorry I can't be more helpful 

best wishes

>Ozone Gap `Deadly as harpoon' for whales
>  By Amanda Brown, Environment Correspondent, PA News
>   The hole in the ozone layer is as "deadly as the harpoon" to the
>dwindling whale population, according to research out today.
>   The sun's powerful ultra violet rays pour through the gap,
>attacking the reproductive ability of plankton, the tiny animals at
>the bottom of the food chain.
>   This in turn causes nutrient shortages for fish and whales.
>   But a new threat has emerged with the discovery that the Northern
>Hemisphere is even more vulnerable to the damaging effects of ozone
>depletion than Antarctica, where the problem has been fairly well
>   The results were unveiled in an Environmental Investigation Agency
>survey published at the International Whaling Commission conference in
>Monte Carlo.
>   Now the EIA is demanding urgent action to bolster whale
>conservation in light of new research.
>   Steve Trent, head of campaigns at the EIA, said: "Ozone depletion
>is just as deadly as the whaler's harpoon.
>   "Some members of the IWC seem stuck in a time warp, and should
>start taking these new threats to whales much more seriously. Whale
>conservation is no longer just about how many whales we can kill."
>   At the base of the food chain, Arctic phytoplankton have a much
>smaller capacity than Antarctic phytoplankton to adapt to increased
>UV radiation.
>   In the Arctic Ocean, a concentration of nutrients near the surface
>of the water in ice-edge zones promotes a longer and more intense
>exposure to UV radiation.
>   Fish species such as cod, on which Northern Hemisphere whales feed,
>spawn in fully exposed shallow waters, where they are highly
>vulnerable to the adverse effects of increased UV radiation. The
>spawning period, which is critical for the species' survival,
>coincides with the period of maximum UV radiation in the Arctic region.
>   Mr Trent added: "It is madness to contemplate a resumption of
>coastal whaling when new and unpredictable threats to whales, such as
>ozone depletion, are only beginning to emerge.
>   "A 50-year moratorium on all whale hunting is the only sensible
>approach when whales are threatened, not just by ozone depletion but
>by climate change, industrial fisheries and pollution."
>   Chris Stroud, Whale and Dolphin Conservation Society spokesman said
>sensible governments should condemn "scientific" whaling as a form of
>phoney science and nothing more than a form of continued commercial
>   He said the IWC scientific committee had "failed to institute
>mechanisms of review which would be generally considered consistent
>with good science - those involved in the research are part of the
>review and thus even basic standards of impartiality are not met."
Dolphin Research Group
The Swire Institute of Marine Science
The University of Hong Kong
Cape d'Aguilar
Hong Kong