Purse-Seining Affects Traditional Fishers of Japan

Since the introduction of purse-seining (a purse-shaped net for encircling surface dwelling fish)in 1949, things have never been quite the same for Japan’s fisheries. Not only have stocks of diverse fish species dwindled, but Japan’s artisanal pole-and-line (a fishing method using pole and line)fishermen have been put to immense misery. Japan’s small-scale fishermen also use trolling (dragging multiple hooks from a boat to harvest surface dwelling fish)and small gill nets (walls of netting set in particular patterns to trap fish)to catch migratory species like mackerels and skipjack tunas as well as non-migratory species like alfonsino.

Traditionally, their fishery has been open for anyone to enter but some degree of self-regulation to control resources has existed. For instance, to protect the alfonsino fish during its breeding season, the fishermen themselves declare a four-month closure.

No such compunctions bother purse-seiners. Usually, four to five of them make up a fleet, which casts the net over 500 metres deep, catching a vast diversity of fish. About 80 per cent of tuna landings are by purse-seiners. A purse-seiner can catch over 400 tonnes of fish at one time. In contrast, small-scale vessels catch just 40 to 100 kg per day.

Purse-seining is a licensed activity allowed only in the three seas of the Northern Pacific, Central Japan and Western Japan. Initially, Japanese purse-seiners operated only in the northern end of the Northern Pacific area to catch yellow-fin and skipjack tunas. But once these stocks got depleted, they moved southwards for other species.

This trend, which began around 1965, directly encroached into the area and activity of small-scale fishermen. When it reached Chiba Prefecture in 1973, for instance, the competition completely wiped out pole-and-line fishing in a couple of years.

Many of the 2,000 small-scale fishing boats of Chiba were forced to idle as their catches were priced out of the market. This was because purse-seiners dumped large quantities of catch, pushing prices down.

Purse-seining has led to indiscriminate overfishing. Purse-seiners are said to catch even juvenile skipjack tunas, each weighing under a kilogram and measuring less than 50 cm. long. One indication of the drop in catches of mackerels, for instance, is the increasing amounts of imports from Norway of this once cheap and popular species.

A fisherman from Kochi Prefecture, traditionally a rich ground for pole-and-line fishing for skipjack tuna, told Greenpeace Japan, "When I first started working for pole-and-line boats back in the 1960s, the catch was so good that you only had to operate from March to September in the offshore of Kochi, up to about 1,000 km to Hachijo Island south of Tokyo. One boats catch of 200 to 300 tonnes was enough to balance costs".

"Today," he continued, "I start operating the boat in January, chase the stock as it moves, as far up as to the north of Hokkaido, which is more than 3,000 km of travel, until December. Some among the 140 pole-and-line fishing boats can only catch 200 tonnes by operating all year".

The problem is compounded by the diverse methods for fisheries management used and the absence of scientific estimates of even the major fish stocks in Japanese waters. Another obstacle is the compartmentalisation among the various government fisheries agencies.

The failure to manage the fisheries has already led to open conflicts. In some prefectures, there have been demonstrations by 3,000 to 5,000 fishermen. A purse-seiner was surrounded by 300 small boats, that were protesting against its operation in their closed area.

In a letter of appeal last year to the Minister of Agriculture, Forestry and Fisheries, 120 small-scale fishermen from Kozushima Island, Tokyo pointed out that: "We have chosen intentionally inefficient methods, thankful for being allowed to take part of the fish, hoping that enough is left for future generations".