A herring fishery shows that the big picture can be elusive

by Hillel Wright

Nearly all the herring roe now used to make the Japanese new-year delicacy kazunoko comes from North America’s west coast. The ocean-living herring go there in huge numbers to spawn in March, and are met by ranks of predators, including cormorants, terns and gulls, bald eagles, ospreys, dogfish sharks, salmon, seals, sea lions and, not least, fishermen.

As herring-roe prices tend to be extremely high, competition among fishermen can become fierce. However, there is not only competition between one boat crew and another, but also between fishermen and predators — especially sea lions.

In March 1995, Canadian newspapers carried screaming headlines: “Slaughter at Sea!”; “Slaughter on the Beaches!”; “Good Riddance to Fishermen!” These outpourings were a reaction to the discovery of a number of enormous sea lion carcasses along the beaches of Denman Island, which lies adjacent to the herring spawning and fishing grounds. Witnesses reported many sightings of herring fishermen gunning down the huge marine mammals with high-powered hunting rifles.

Concerned islanders then convened a town-hall meeting and invited Marine Mammal Specialist Peter Olesiuk from Vancouver Island’s Pacific Biological Station to address them on the issue. Olesiuk acknowledged that government policy toward marine mammals is influenced by public opinion. While in the 1930s, ’40s and ’50s, sea lions were routinely machine-gunned, public opinion changed in the ’60s and marine mammals became protected by law.

Olesiuk also defined the term “endangered” as being closer to extinction than the term “threatened,” and he pointed out that while the sea lion population was threatened, 95 percent of those around the east coast of Vancouver Island’s herring grounds were males who will never mate. That, he explained, was because sea lion family dynamics produce a few dominant males with harems averaging 20 females. Those sea lions are either on the west coast of the island, or on the California coast in March, so shooting the “bachelors” on the east coast was more a moral or ethical issue than a biological or genetic one in terms of survival of the species in that area.

Olesiuk also explained that protecting all marine mammals may be counterproductively dangerous to the health and stability of the stock itself, which otherwise may become too numerous for its environment and lead to epidemics of disease. And most germane to the controversy is the fact that herring make up just a small amount of the sea lion diet, the bulk of which comprises hake, a relatively valueless fish both commercially and nutritionally — but a major predator of herring.

So, from an ecological point of view, the more sea lions, the less hake and the more herring. This, according to Dr. Olesiuk, is seeing the big picture.