30 July 2022

Seals vs. Cod

From Cod, by Mark Kurlansky (Penguin, 1998), pp. 200-202:

Marine ecology is complex and tightly interwoven. When large factory ships in the North Sea overfish sand eels and other small fish that are ground into fish meal for heating fuel in Denmark, not only cod but seabirds go hungry. In 1986, seal herds ranged south in the North Sea and ate the coastal fish off of Norway because they were famished from the overfishing of capelin. Fishermen were calling for a seal hunt to save the North Sea fisheries from the seal. In 1995, both Norway and Canada rescinded their ban on seal hunting because the populations were growing and they eat cod.

In the late 1950s, Canada’s seal hunt had become a target of environmentalists when high prices for seal pelts and a huge herd had drawn packs of ruthless, unskilled amateur hunters with helicopters to the Newfoundland and Labrador coasts. In 1964, the anger of animal lovers throughout the world was stirred by a film made by Artek, a Montreal film company, that depicted a seal being skinned alive. The international protest did not abate when it was revealed that the skinner had been paid by the film company and that two of the other “hunters” turned out to be part of the film crew. In 1983, after intensive pressure from environmental groups culminated with a European Community boycott of seal products, Canada finally banned seal hunting, a traditional activity in Newfoundland and Labrador.

Not surprisingly, the 1995 reopening of the seal hunt met with national and international condemnation from environmentalist and animal-rights groups. The seal defenders claimed that there was no scientific basis for the seal hunt. Some even denied that seals eat cod. Before protecting the seal became a cause célèbre, everyone in Newfoundland knew that seals ate cod. The familiar label of the leading Newfoundland soft-drink company, G. H. Gaden, is a seal on an ice floe with the words keep cool. But in the less politically correct nineteenth century, a cod was in the seal’s mouth.

According to the Canadian government, the seal-hunting ban caused the harp seal population to double to 4.8 million, and if the ban had not been rescinded, it would be expected to be at 6 million by 2000. Seals eat enormous quantities of fish and are particularly disliked by fishermen because they are wasteful. Like the average North American consumer, gray, harbor, and harp seals do not like to deal with fish bones. They tear into the soft belly of the cod and leave most of the rest. “Seals don’t have to eat a lot of cod to have a big impact,” said George Rose. “It doesn’t mean we have to declare war on the seal. But we have to control the seal population.” One Canadian journalist, recalling Brigitte Bardot’s 1977 campaign in which she posed on an ice floe with a stuffed baby seal, suggested that the French actress pose hugging a codfish.

Given the interdependence of species, the fundamental question is whether other species—not just the seals but the phytoplankton, the zooplankton, the capelin, the seabirds, and the whales—will wait fifteen years for cod to return. Nature may have even less patience than politicians. “Whatever will work is going to work. It will not necessarily come out the same way,” said Rose. If the species that were eaten by cod become plentiful because the cod are not there to prey on them, other species may move in, and if the intruders are successful, there might not be enough food to support a large cod population again. Some biologists worry that rays, skates, and dogfish, which are small sharks, may already be moving in.

In addition, an unwanted relative has already shown up: the arctic cod (Boreogadus saida). This may not be bad for the marine ecology, but it is very bad news for fishermen. Arctic cod are about eight inches long and until now have been deemed of little commercial value. Because they are a much smaller fish, the adults do not compete with the Atlantic cod for food, but the young do. Even worse, arctic cod eat Atlantic cod eggs and larvae.

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