Antarctic Whaling

From: Pieter Arend Folkens (animalbytes@earthlink.net)
Date: Thu Nov 15 2001 - 02:52:50 EST


>We are three schoolstudents from Danebank School, Hurstville, NSW 2207,
>Australia, currently in our final year of Primary School. Please could
>you answer the following questions?
>
>1. What is the effect of allowing the Japanese to catch whales in
>Antarctica?
>2. What proportion of the estimated original population of whales srill
>exists in Antarctica?
>3.How do you think people will become affected if whales become extinct?
>4. What will be the effects on the ecosystem as a whole, should whales
>become extinct?
>5. Is it OK to hunt and kill whales for scientific research and if so,
>which species?
>6. How long will it take before whale populations recover their numbers
>to the levels of before commercial whaling.
>7.How can whales be exploited commercially without causing any damage to
>the ecosystem.

1. We do not necessarily "allow" Japan to whale in the Antarctic.
They insist on doing it, and just go ahead. Some of the effects are:
a. Japan keeps its whaling fleet busy and profitable.
b. It restricts the ability of the depleted whale stocks to recover
from historic over whaling.

2. The remaining proportion depends on the species of whale. Minkes
are probably pretty close to their original numbers, and some have
suggested they have expanted into ecological niches previously
occupied by blue whale.
Blue whales are thought to be around 15% of original estimated
numbers. Right whales were brought down to less than 10% of the
original numbers, but in the Antarctic, right whales appear to be
recovering. I do not know the present proportion compared to
historical estimates. Humpbacks and fins are also thought tobe
recovering.

3. and 4. Cetaceans (whales) represent a substantial biomass in the
marine environment. In any environment/ecological system, if a major
and active element of the system is removed, the system is
de-stabilized. This results in wild swings in the ecological balance
as other organisms exploit, or are impacted by the void left by the
missing element. It takes a long time for the system to become stable
again. The time it takes depends on the size of the environment and
the importance of the organism in that environment. For example,
after the dinosaurs disappeared, it took literally hundreds of
thousands of years before a reasonable sense of stability was
accomplished, and even so, that major element -- the dinosaurs --
never came back. When a volcano eruption wipes out a forest, the
first signs of life appear the next year, and a climax forest
(balanced system) is accomplished after a few hundred years. In a
small system, such as a farm pond, the system may become stable again
after only a few years.

Regarding the extinction of whales in particular, the food they eat
will grow out of proportion with their food resources. The amount of
these organisms will fluctuate wildly for many years. When gray
whales nearly went extinct, the benthic biomass they feed upon at the
bottom of the Bering Sea became stagnant and unhealthy. Once grays
returned in numbers, they began plowing up the benthos, and health
returned to the system.

5. Acquiring specimens for scientific research is okay -- even of
endangered species when and where necessary. However, it is not okay
to conduct commercial exploitation of protected species under the
ruse of science -- especially when there is no demonstrated need for
the data.

6. Gray whales received total protection in 1933. It is assumed the
population hit a low before 1920. The population appears to have
settled into a stable number in the late 1990s. So for this species
it took around 65-70 years. However, there is some opinions that the
carrying capacity of the modern environment is not as great as it was
a hundred years ago. So, even though grays have attained a stable
population, the size of that population may not be as great as it was
historically.

Receiving protection does not necessarily assure the recovery of a
species. Right whales have had protection for nearly as long as
grays, but they have not recovered. In fact, the North Atlantic
population is still declining from its present number of around 300
individuals. This does not bode well for the species. The problem for
right whales appears to be a polluted environment that diminishes
their food supply and vessel traffic in important whale gathering
areas.

The important point is that the environment must be healthy for the
various organisms to survive and prosper. We cannot save a species
without also saving its environment.

7. There are mathematical formulas that have determined how much of
a stable population can be "culled" before the stock becomes
depleated or "reproductively stressed" and the environment affected.
This "recruitment" varies depending on the species. For example,
seals have many more pups than are expected to survive. Many (if not
most) of these pups become food for other species such as sharks and
killer whales. More of these can be culled commercially without
affecting the health of the system. Toothed whales, on the other
hand, have very few offspring, as is common for intelligent species
that "invest" more into their calves. Commercial exploitation cannot
be sustained for very long with toothed whales, if at all.

I hope that I've answered your questions sufficiently.

Cheers,

Pieter Folkens

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