Man vs. Sea Mammals
from the book, "Our Fascinating Earth"
Man vs. Sea Mammals
Throughout many of the fishing grounds of the world a perplexing problem has developed between man and seagoing mammals. The struggle has become acute, principally because seals, dolphins, and some related species of whales hunt very successfully for the same fish sought by commercial fishermen.
The struggle has existed for decades, but with increased demand for seafood by humans the rivalry has become critical. In 1979 a group of Japanese fishermen herded more than 1,000 dolphins onto the beach, where they clubbed them to death. They contended that a school of dolphins that large consumes over fifty tons of fish per day.
The competition for fish takes on many forms; along the Columbia River in Oregon fishermen closing their nets on salmon often find harbor seals darting in and grabbing their catch. Considering that a thirty—five—pound salmon is worth about $100 to the fishermen, this is quite a loss. The fishermen say the seals just relax in the sun, waiting for them to open the nets, and then in they go.
Punitive action such as that taken by the Japanese could result in mass extinctions of already threatened species. However, other forms of retaliation have begun, as numerous seal carcasses containing bullet holes have washed ashore in the Pacific Northwest.
In Antarctica several major fishing nations are planning to exploit the vast schools of krill, a two—inch shrimplike crustacean. This competition will inflict significant damage to some of the great whale populations which now subsist entirely on krill. Each year the great whales consume almost fifty million tons of krill, even at their present reduced numbers. Removal of their food supply, which they share with seals, penguins, and squid, could spell the end for the largest creature that ever lived on the planet — the gigantic blue whale.
Scientists have inaugurated several programs of study designed to solve the problem, but as might be expected, they are proceeding slowly — much too slowly!