The story of Atlantic bluefin tuna is a cautionary tale of explosive growth, management neglect, ignored science, falling populations, and an uncertain future. Involving an international cast of characters stretching across the Atlantic and Mediterranean Sea, from the earliest fishermen in ancient Greece to the scientists and advocates fighting today to ensure a sustainable future, it is an illustration of what happens when big money and sustainability go head to head.
At the centre of the story is an apex predator that grows to the size of a small car, out-swims almost every other fish in the ocean, and brings bids of tens of thousands of dollars at fish markets around the world. It is an amazing species, commanding the awe of nature lovers, the dollars of sushi lovers, and the respect of fishermen. It also generates political and diplomatic controversy among some of the world’s richest and most powerful countries.
In the Atlantic Ocean, bluefin tuna are born into one of two populations – the eastern population that breeds in the Mediterranean Sea and the western population born in the Gulf of Mexico.
While the eastern and western stocks of the tuna have their own unique story and history, both have been affected by intense fishing pressure, declining numbers and large gaps in scientific understanding – and both will be greatly affected by upcoming management decisions.
In October 2012, the International Commission for the Conservation of Atlantic Tunas (ICCAT), the organization charged with managing Atlantic bluefin tuna, finalized new stock assessments showing an increase in both the eastern and western populations. Recognising the high degree of uncertainty in the models, ICCAT’s scientific committee (SCRS) recommended that quotas remain the same to allow bluefin populations to continue to grow. While this is good news, the story is far from over and bluefin managers must carefully nurture this fragile recovery and not undermine improvements before they can take hold.
In November 2012, ICCAT member governments must now apply these recommendations from the ICCAT scientific committee to their decision-making. Governments must look to the future: before considering increasing quotas they should ensure that the scientific models used to determine the status of the population and for setting appropriate fishing levels are sound and that illegal fishing is accounted for and addressed.
Key discussions among ICCAT members are taking place right now in conjunction with the new stock assessments. Decisions are being made behind closed doors that will determine these quotas. ICCAT members must now apply the recommendations from ICCAT’s own scientific committee to their decision making.
The Eastern Bluefin Population: Big Catches, Big Problems
While bluefin tuna have been part of Mediterranean cultures for thousands of years, the 1990s marked the beginning of the industrial scale fishery in the eastern Atlantic. That decade witnessed a significant increase in the size of the purse seine fleet – fishing boats that use large nets to surround entire schools of bluefin. Rising Japanese demand for fatty tuna to supply the increasing appetite for high-quality sushi also led to the development of tuna ‘ranching’, where smaller, wild-caught fish are placed in floating pens and fattened for months or years before being sold. Although quotas were introduced in 1998, illegal fishing, the rising price of bluefin, and government subsidies led to a significant increase in catch. By 2007, fishing fleets were catching up to an estimated 60,000 metric tons (mt) of bluefin annually, more than double the quota for that year. Most of this tuna went to Japan, which consumes close to 80 percent of the bluefin caught each year; the majority of this comes from the eastern Atlantic stock.
These elevated catch levels continued throughout the 2000s as government managers set quotas well above the scientifically-recommended level for a sustainable fishery. An independent review commissioned by ICCAT in 2008 called ICCAT’s eastern bluefin policies a “travesty of fisheries management” and “an international disgrace”, but even this did not motivate governments to act in the interest of a long-term, profitable and sustainable fishery. In 2008 an ICCAT stock assessment showed that the eastern bluefin population had fallen to 60 percent below the 1970 level. In 2009 many governments and environmental organizations called for a suspension of international trade of bluefin; ICCAT finally responded by reducing quotas to scientifically-recommended levels. The story of eastern bluefin tuna does not end there, however.
Although governments implemented stricter quotas in early 2010, there has not been a similar reduction in the fishing fleet. Despite an ICCAT programme to reduce fishing capacity, the number of vessels remaining still has the collective capacity to catch three times the allowable limit. This overcapacity, which occurs when governments increase capacity or prevent a reduction in the number of vessels, facilitates increased illegal fishing. The most recent bluefin trade studies show that illegal catch in the east continues today, even as ICCAT has instituted stricter enforcement measures. A new scientific study estimated that between 2005 and 2011 actual catch exceeded the total allowable quota by 62 percent and the difference increased to 77 percent between 2008 and 2011.
Added to the overcapacity and under-reporting is the ongoing problem of the illegal use of driftnets to catch bluefin. Although the European Union and ICCAT both banned their use for catching large open-water species nearly a decade ago, driftnets continue to be used by Italian vessels to catch Atlantic bluefin in one of the most well-known and destructive cases of illegal fishing by European vessels. Current regulations, enforcement and sanctions have failed to stem the use of these nets to catch bluefin, one of the most sought-after fish in the sea.
Despite strong evidence of continued illegal activity, the eastern bluefin stock assessment uses reported catch instead of the total numbers of fish removed from the sea, ignoring any recent illegal catch.
The Western Bluefin Population: Will the Promised Recovery Ever Happen?
Prior to 1950, fishermen in the western Atlantic had little interest in catching bluefin tuna. But in 1964, drawn by increasing demand for bluefin, longline vessels fishing off the coast of Brazil and purse seine vessels targeting small juvenile fish in New England waters caught approximately 18,000 mt of bluefin tuna. This intense fishing pressure soon took its toll on the smaller western bluefin population, causing catch to fall by 80 percent at the end of the decade. It remains low today.
In 1998, recognising that the population was at a historic low, at 28 percent of the 1970 level, ICCAT implemented a recovery plan that set quotas and instituted a minimum size limit. Unfortunately, the plan proved unsuccessful and the population in the western Atlantic is now at 36 percent of historic levels or virtually the same today as it was 15 years ago when recovery efforts first began.
There are several reasons why the recovery plan has not worked as designed. For the western Atlantic, ICCAT scientists use two contrasting scenarios when they estimate the number of young bluefin that survive each year. The ‘high recruitment scenario’ assumes that the number of new offspring is directly related to the number of adults, while the ‘low recruitment scenario’ assumes there is a cap on the number of young born each year, regardless of the number of adult or spawning fish. These scenarios provide very different outcomes and hence recommendations for managers, which can range from shutting down the fishery to increasing the quota. As a result, managers have been forced to make decisions using two conflicting sets of information. So far, the decisions have completely failed to produce a meaningful rebound in the population.
Complicating the situation even further is the significant number of eastern bluefin that migrate from the Mediterranean Sea to feed in the western Atlantic. For many years, scientists believed that these two populations were entirely separate, staying on their own sides of the ocean basin. However, recent scientific studies show evidence of high levels of mixing between these two populations, with eastern bluefin travelling to western waters in search of food.
It is now estimated that 72 percent of the bluefin caught off the east coast of the United States come from Mediterranean stock. Since this migration is not accounted for in ICCAT’s model, the eastern fish are counted as western, leading to an inflated estimation of the number of western bluefin. These higher counts cause the assessment to provide an overly optimistic picture of the health of the western population. To improve the accuracy of the scientific projections, this information must be incorporated into any future stock assessment.
The Future of Bluefin
According to the 2012 stock assessment, the eastern Atlantic bluefin population has increased in recent years, but ICCAT scientists acknowledge the large amount of uncertainty surrounding the magnitude of the growth. The western Atlantic bluefin stock assessment suggested a slight increase but, again, ICCAT scientists recognised the uncertainty of the results. Since the stock assessment models are admittedly flawed and fail to take into account all the best available information and science, the results must be treated with caution and must not be used as a rationale for increasing quotas.
Instead, governments should heed the scientific advice to not increase the current quotas and allow both populations to grow while ICCAT works on updating its outdated stock assessment models. If anything, the 2012 results are a positive sign that the stronger management measures taken since 2009 are beginning to yield results and should be reinforced.
ICCAT members must now apply the recommendations from ICCAT’s own scientific committee to their decision making.
A future for bluefin depends upon governments heeding scientific advice to exercise caution and not increase the current fishing quotas in the east and west until the following critical steps occur:
The bluefin stock assessments are revised and updated to include all available reliable science and data in order to make them a solid basis upon which government managers can set meaningful quotas;
- ICCAT addresses illegal fishing in the east, which includes holding illegal fishing vessels and the governments that flag them accountable, as well as swift implementation of an electronic catch document system to track bluefin tuna.
ICCAT took important steps in 2009 when, for the first time, it set quotas for eastern bluefin tuna in accordance with scientific advice, and again in 2011 when it launched a pilot programme to help combat illegal fishing by electronically tracking bluefin from sea to sale. Now, when there are signs that the bluefin populations may be slowly increasing, the actions detailed above are critical in driving real recovery for this important species.