Casting our nets too wide: should tuna farming practices be more strictly regulated?

Japan, Inc., Feb, 2005 by Bonnie Lee La Madeleine

An early morning trip to the famous Tsukiji fish market is a standard part of any tourist's visit to Tokyo. This market has been an integral part of Japan's identity for decades and was until recently a critical player in the distribution of Japan's daily supply of fish. It is also an important keystone for several industries. One is the lucrative, if problematic, tuna fishing industry. Tsukiji market auctions off a significant portion of the sashimi grade tuna (toro).

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Behind the veil of this quaint market can be found a complex web of interests supporting the acquisition and distribution of sashimi grade tuna.

We like tuna. Tuna--fresh, frozen or canned--is a staple in diets around the world and, thanks to recent, overly optimistic findings on the health benefits of the Omega-3 fatty acids found in fish like salmon and tuna, these fish are becoming increasingly integral to the diets of people in developed nations. The popularity of tuna loin and sashimi is growing internationally and has nearly doubled in the United States over the past few years. In 2004 over 100,000 tons of tuna loin was shipped Stateside. Even our pets are developing finicky preferences for better quality tuna--a preference we freely indulge.

Therefore, fisheries love tuna. With annual revenues for canned tuna alone exceeding $2 billion, this infatuation is understandable. Bluefin is the largest of the various tuna species caught and marketed annually. Bigeye, skipjack, yellowfin, and abalcore enjoy large and growing markets, but bluefin, which can reach three meters and weight over 650 kilograms, still has the most appeal. A single live bluefin of high meat quality averages [yen]250,000 but, depending on the marbling of fat and market demand, could be significantly higher.

Drawn by those potential profits, an increasing number of nations, companies and researchers are developing more efficient technologies to improve catch quality and size. Yields and profits have increased with advances in longline fishing and tuna-ranching technologies. Tuna has become a billion-dollar industry with successful synergies on either side of the tuna value chain--so successful that some experts predict the tuna market's collapse and the Atlantic bluefin's commercial extinction within a few years.

A meeting to determine the true state of bluefin tuna stock and develop better management strategies of that species will be held this April in Fukuoka. Members of the ICCAT (International Commission for the Conservation of Atlantic Tuna) will meet from April 20 to 23 to air concerns about the overfishing of tuna that led to the current oversupply in Japan. They also hope to set an agenda for farming management to protect both the ocean and the tuna.

The stakes are clear. If bluefin tuna is in jeopardy because of farming practices, then farming will need stricter regulations to ensure that other tuna species do not suffer the same fate. But can this meeting accurately access these questions and develop a solution that all stakeholders will abide by?

The False Promise of Aquaculture

Tuna farming, under the guise of "aquaculture," arose from efforts to increase tuna supply to the Japanese market. Aquacultural practices seek to find ways to domesticate the production of marine resources in order to increase yields without further depleting the wild marine resources--an eco-friendly way to get fish and seafood to market. More than 220 species of finfish and shellfish, including shrimp, sardines, and smaller species, have successfully been transformed into viable industries, predominantly in Asian nations. China is the current leader in aquaculture. Farming salmon is also possible. However, aquaculture has begun to raise concerns, especially with regard to practices involving carnivorous species that are higher on the food chain and cannot be fully domesticated.

"All aquaculture causes some pollution of the water," says Dr. Peter Miyake, the leading expert in tuna farming. "Tuna is no exception."

In fact, several reports issued last fall reflect increasing concerns about aquaculture-induced pollution, contamination, and risks of disease. Rex Dalton, writing in the September 2004 issue of Nature, cited pollution-related issues at salmon pens in Canada and diseases stemming from tuna farming in Mexico. Increased farming of tuna feed has also led to the rapid viral infection of sardines in Mexican waters. A rapid die-off of sardines could put increased pressures on these tuna farms. In September, the Advanced Tuna Ranching Technologies (ATRT), a fisheries trade organization based in Spain, cited pollution, waste management and disease as increasing concerns for tuna farming.

Tuna fishing and farming

Traditionally, tuna has been harvested using longline, pole-and-line and purse-seine fishing. The last traps a school of tuna and hauls the entire group into the boat, alive. While all have commercial markets, purse seine farming is best for toro because the tuna can remain alive for longer periods and be delivered to market fresh.