This article is provided courtesy of the High North Alliance.

White Sea Harp Seals Nearly Twice as Plentiful as Assumed

High North Web News, Nov. 12, 1998: While the harp seal population in the Eastern ice fields of the White Sea was assumed to number between 600,000 and 700,000, new estimates now put the figure in the range of 1.5 to 2 million animals. The International Council for the Exploration of the Sea (ICES) has on this basis increased its quota recommendation from 40,000 to 61,100, reports the Norwegian newspaper Aftenposten (Nov. 9).

The Russians have previously carried out counting surveys using methods and analyses that were considered unreliable. But last year the counts were carried out using the same methods as Canada and Norway, which are considered far more reliable, says Nils Øien of the Institute of Marine Research in Norway. Estimates of the seal stock are based on calculations of the number of young born each year.

The recommended harp seal quota for the Western ice fields (Jan Mayen area) has also been increased, from 13,100 to 17,500. This population is estimated at consisting of 400,000 animals of at least one year of age, writes Aftenposten.

Based on the 1997 surveys of the hooded seal population in the Western ice breeding patches, provisional analyses indicated that the quota should be reduced. As a result of this, and as a precautionary measure, the quota was reduced from 9,000 in 1997 to 5,000 in 1998. A comprehensive assessment of the stock has now been conducted and it is estimated to consist of 110,000 hooded seals at the age of one year or older. The quota recommendation has been increased to 11,200 adults, or 18,000 pups.

It is expected that the Joint Norwegian-Russian Fisheries Commission will follow the scientific recommendations when the catch quotas are decided.

When asked by the newspaper as to whether the large number of seals might provide an explanation for the decline of the fish stocks in the north, Nils Øien of the Institute of Marine Research replied that, "It is part of the picture, but by no means all of it."

Studies carried out by the Norwegian Institute of Fisheries and Aquaculture show that seals eat considerable amounts of fish and fish feed. For instance, the Eastern ice field population of harp seal consumes between 1.1 and 1.7 million tonnes of biomass annually, consisting of the following menu: 390,000 - 550,000 tonnes of marine crawfish, 260,000 - 410,000 tonnes of capelin, 190,000 - 430,000 tonnes of polar cod, 70,000 - 205,000 tonnes of herring and 30,000 - 150,000 tonnes of cod. It is worth noting that this consumption is based on the assumption that the stock size was 600,000, and not the most recent one of 1.5 to 2 million harp seals. Needless to say, the more seals, the higher the consumption.

The minke whale along the Norwegian coast and in the Barents Sea also has a considerable appetite, and annually eats about 1.8 million tonnes of biomass. Its 1996 menu consisted of 600,000 tonnes of krill, 630,000 tonnes of herring, 140,000 tonnes of capelin, 255,000 tonnes of cod, 130,000 tonnes of haddock and 55,000 tonnes of other species such as saithe and sand eels.

In other words, the harp seal and the minke whale together consume about the same amount of biomass as the Norwegian fishermen land, i.e. about 3 million tonnes. The consumption of other marine mammals in the region has not yet been calculated.

The relationship between seals and fishermen is understandably one of conflict as they are competing for the same resources. The maintenance of super-abundant marine mammal stocks untouchable by man (or subject only to a very limited catch) leads to an entire segment of the ocean food chain being inaccessible to fisheries. This reduces the possible sustainable yield of the marine ecosystem.

In the US, too, marine mammals help themselves to the fish stocks. Data from the National Marine Fisheries Service shows that seals and sea lions on the west coast now consume 285,000 tonnes of fish. This is an increase compared to the 1993 consumption of 217,000 tonnes. In the year 2004 their consumption is expected to reach 396,000 tonnes, i.e. approximately the same amount as caught by fishermen (Aftenposten, June 4, 1998, quoting Pacific Fishing Magazine).

The exact impact of marine mammals on fisheries remains to be settled, but that they have a considerable impact is beyond any doubt. In order to improve our knowledge of this issue, and to integrate it into a multi-species management approach, the North Atlantic Marine Mammal Commission (NAMMCO) instructed its scientific committee earlier this autumn to investigate further the economic aspects of marine mammal-fisheries interaction, and in particular to discuss the economic consequences of different catch-levels of marine mammals vs. no catch at all.

For further information from the site of the High North Alliance:

"Competitors" / Cod and Saithe Eaten by Invading Seals / EU Resolution on Seals/Fisheries Interaction / Sperm Whales Do Not Only Eat Squid

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