The U.S. pamphlet says "As a whole, whales do not eat large
quantities of fish as food" however, a recent study presented to the
International Whaling Commission’s Scientific Committee (Tamura and
Ohsumi, 2000) conservatively estimates that annual fish consumption by
cetaceans in the Southern Hemisphere is 18 to 32 million tons. In the case
of the North Pacific, fish consumption was estimated to be 21-30 million
tons and in the North Atlantic, 15-25 million tons. Much of this fish is
comprised of species subject to commercial fishing. Clearly, scientific
facts contradict the statements of the U.S. Department of Commerce.
The U.S. pamphlet uses simple "facts" such as "humans are
primarily responsible for fisheries declines", "predatory and
cannibalistic fishes consume vastly greater amounts of commercially
valuable fish than do marine mammals", and "many whales feed on
krill and fish species not used by humans" to dismiss the significance
of fish consumption by whales. Presentation of these simple
"facts" ignores scientific findings that clearly show fish
consumption is important and often in direct competition with fisheries for
human food.
Clearly, fisheries management organizations must address issues such as
excess fishing capacity, illegal and unregulated fishing and other problems
(indeed Japan has responded to the FAO by significantly reducing its tuna
longline fleet) but at the same time, more effective management of marine
resources means that we cannot ignore the issue of fish consumption by
marine mammals when there is a growing demand by humans for fish and when
whale populations are increasing.
Similarly, while predatory and cannibalistic fishes do consume large
amounts of commercially valuable fish, most of this consumption is
comprised of larval or juvenile fish in their first year. This predation is
part of "natural mortality" and has remained relatively stable.
However, since the moratorium on commercial whaling was imposed, whales are
increasing and their corresponding increasing consumption of fish
represents a new factor that can’t be ignored.