Ensuring a Sustainable Future for the Bluefin Tuna Fishing Industry

Image of Tuna swimming

(Credit: Unsplash)

by | Jul 12, 2011

This article is included in these additional categories:

A study released on April 19, 2011 by the International Union for Conservation of Nature (IUCN) offers a dire prediction: More than 40 species of marine fish currently found in the Mediterranean Sea could disappear in the next few years. According to the report, commercial species, including the Bluefin Tuna, are considered threatened or near threatened with extinction at the regional level, mainly due to overfishing.

“The Mediterranean and Eastern Atlantic population of the Atlantic Bluefin Tuna (Thunnus thynnus) is of particular concern,” wrote Kent Carpenter, IUCN Global Marine Species Assessment Coordinator, in the study.  “There has been an estimated 50% decline in this species’ reproduction potential over the past 40 years due to intensive overfishing.  The lack of compliance with current quotas combined with widespread underreporting of the catch may have undermined conservation efforts for this species in the Mediterranean.”

This statement is baffling given the best available information on the issues of the Mediterranean and Eastern Atlantic Bluefin stock. The “widespread underreporting” and “lack of compliance with current quotas” may refer to incidents before the 2008-2010 reform of the International Commission for the Conservation of Atlantic Tunas (ICCAT), as no reports of illegal fishing have been filed since 2009, according to ICCAT’s illegal vessel list, in spite of much strengthened policing of the waters and tighter control of the fishing. The study also contradicts the result of ICCAT’s scientific body, SCRS, which published a report in autumn 2010, the most comprehensive assessment of the status of the stock ever made.

With the exception of the Atlantic Bluefin over the past two years, the Atlantic Bluefin stocks did suffer from a lack of coordinated management over the last few decades. However, there are practices that seafood companies can adopt to ensure the sustainable use of the world’s Bluefin stock.

As concerns over depleting the natural stock of Bluefin Tuna have increased in recent years, ICCAT has reduced the total available catch for the Eastern Atlantic Bluefin Tuna (NBT) from 32,000 metric tons in 2006 to 13,500 tons in 2010 and 12,900 in 2011.  A stock assessment conducted by SCRS in October 2010 calculated the Mediterranean stock of Atlantic Bluefin Tuna at approximately 175,000 metric tons, a significant improvement over a 2007 estimate of 78,000 metric tons, 57% of the historical highpoint of the stock in 1955-1957.  Management measures put in place by ICCAT have outlawed illegal unreported catches and set the stock on a track to regain its former prominence. According to SCRS, the scientific body of ICCAT, the stock is expected to reach equilibrium in 2022, given the current quota of 12,900 metric tons.

Any viable sustainable tuna fishing strategy will be built around a set of objectives.  For example, it is vital that the company strictly adhere to the catch levels scientifically required to permit the replenishment of Bluefin and other overfished species in particular regions.  Also, farming tuna in cages will help to increase biomass and to decrease the need to overfish wild stocks.  It may also be practical to spawn the farmed fish and fertilized eggs, and release those eggs back into the natural environment.

It is equally important that there be no predators, such as sea otters, sea lions or sharks, in the waters that might attack the fish in captivity.  The waters where a company’s farming sites are located ought to be as pristine as possible, preferably with no cases of red or blue tide caused by the damaging build-up of algae, and with no industrial production nearby.  Islands surrounding a farm site can offer natural shelter against most storms; in addition, the salt and oxygen levels and the water temperature must conform to conditions favorable for sustainable growth of the tuna.

In a best-case scenario, Bluefin tuna would be fed only whole, small pelagic fish, with no chemicals, drugs or additives included. In this way, it may be possible to maintain a feed-conversion ratio measurably lower than the 25-30:1 ratio required in the wild.  In this way, the company can potentially sustain its stock of tuna with considerably less feed than what even Mother Nature can manage.

Sexually mature fish in captivity will spawn in their cages, releasing fertilized eggs into the wild. A propagation program involving the commercially viable breeding of the northern Bluefin Tuna could eliminate the need for wild catch and perhaps eventually close the life cycle of the species in captivity.

All fishing should be subject to quota, based on a scientific assessment of maximum annual yield.  The following key operational highlights form an integral part of any sustainability platform and would justify its characterization as an environmental or green technology investment.

The fundamental platform of the business should be to produce a high-quality and sustainable protein food source with minimal impact on the ecological environment in which the company operates, and among other goals, to help restore balance in the global stocks of Bluefin Tuna by supporting the continual reduction of international catch quotas and the continued development of more effective farming methods.

A company should be aware of the efforts made by both the ICCAT and CITES organizations in lobbying for reduced international quotas for Bluefin.  Quota reduction and international cooperation among key Bluefin producers in the Mediterranean and elsewhere is the only sensible way to stabilize and restore stocks to sustainable levels.

Farming, as opposed to “catch and kill,” is the only real alternative to ensure sustainability of this highly important component of the marine food chain.  A continuous investment in the development of feed technology and organic farming methods for Bluefin may result in superior food-conversion ratios.  This stands to increases both the size and growth rates of the fish, resulting in higher production and reduced reliance on catching quota allocation.

As with the salmon industry 20 years ago, the farmed component of the Bluefin market may very well increase over the next 10 years.  As demand for high-quality protein and low-environmental-impact food sources increases with global population growth and increased distribution of wealth, there is increased incentive for companies to occupy the forefront of the global trend to sustainable seafood.

Significant and continuous investment in the development of “closed cycle” farming technology will ultimately result in an economically viable Bluefin farming business built around an in-house breeding program.  Any company striving to be a global leader in this process will reduce reliance on wild-caught Bluefin and commercialize the market from its current highly niche status, much in the same way as closed-cycle salmon farming was able to incrementally increase the global supply and consumption of salmon.

The ideal farming process will have minimal impact on a company’s operating environment, being non-pollutive.  No pesticides, hormones, fertilizer or other non-organic products should be used at any time in the farming process, including feed, which generally consists of sardines, anchovies or other pelagic fish.

No fresh water should be consumed in the farming process; all operations should be seawater-based.  This strategy will wind up comparing very favorably with protein alternatives such as beef, where high levels of water and grain consumption per kilo, together with collateral use of non-organic chemicals such as fertilizer, constitute a heavy environmental impact.

Ideally, the feedstock requirement will be caught by the company’s own vessels; if sourced from outside the company, the feedstock should be purchased only from recognized sustainably managed resources.  The company’s catching methods for juvenile fish for the farming process should be based on a system such as purse seining, which ensures no collateral impact on the marine environment and no bycatch losses.

A sustainable fish farm must create no non-organic waste products, and fish should be reared in areas known for clean, natural seawater with negligible levels of toxic chemicals such as mercury or lead.  It is advisable that most of the small pelagic fish not used by the company will end up in feed formulas after having been dried first, through a contaminating rendering process.

If the sustainable business practices outlined above are adopted on a sufficiently wide scale, everyone will be able to enjoy a piece of sustainably grown sashimi on their plate.  Sustainability practices represent a major step in keeping the prized Bluefin Tuna thriving—and on our tables as well.

Oli Valur Steindorsson is Chief Executive Officer of Umami Sustainable Seafood, a holding company of fish farms supplying sashimi-grade Northern Bluefin Tuna to the global market.  He can be reached at [email protected].

Additional articles you will be interested in.

Stay Informed

Get E+E Leader Articles delivered via Newsletter right to your inbox!

This field is for validation purposes and should be left unchanged.
Share This