Pacific Bluefin Tuna In Jeopardy

Lessons not learned equals a species in danger

November 11, 2016
Pacific bluefin tuna conservation
Scientists believe only about 100,000 or so of the popular Pacific bluefin remain. Antonio Varcasia

In A.D. 64, a massive fire ravaged Rome for six days, destroying some 70 percent of the city. During that time, it is said that reigning emperor Nero did nothing to address the problem — leading to the popular phrase: “Nero fiddled while Rome burned.”

Call me crazy, but I can’t help but think that we’re currently witnessing a similar situation with Pacific bluefin tuna.

There are three species of bluefin: Atlantic, southern and Pacific, and we’ve been reading about how two of them have been mismanaged one way or the other for at least the past three decades. Atlantic bluefin probably garnered the most press over the years following their precipitous decline, which began as early as the late 1960s. We learned this was an intricate situation with two distinct fish stocks (eastern and western), discrete spawning areas and a relatively late age to sexual maturity. This, coupled with a meteoric rise in global sushi lust, absurd prices paid for individual fish, under-reported commercial landings and a tuna “ranching” shell game, caused Atlantic bluefin to slide into the ditch big time.

Pacific bluefin tuna
Commercial-fishing efforts for Pacific bluefin leave small chance for recovery. Barry Brightenburg

Southern bluefin shared a similar experience. Intensively fished since the 1950s, and with a much lower virgin biomass than Atlantic bluefin, it was declared critically endangered by the International Union for the Conservation of Nature in 1996. When this species was reassessed by the IUCN in 2011, it was estimated that the spawning stock biomass had declined by 85 percent over the previous 36 years. Alas, like its northern cousin, southern bluefin had all the same life-history traits and gustatory attributes to create a perfect storm for overfishing and mismanagement.

But what about Pacific bluefin? All those years we were learning the hard way that Atlantic and southern bluefin tuna were complex critters and were being poorly managed, nobody really ever said boo about Pacific bluefin. That is, until the first publicly available stock assessment was published in 2012 by the International Science Committee for Tuna and Tuna-like Species in the North Pacific Ocean, which basically said: surprise! The stock is severely depleted, if not bordering on a complete collapse.

Yep, literally out of nowhere, it was unexpectedly reported that this species’ spawning stock biomass had been reduced by a whopping 96 percent. Inconceivably, after all those years of lamenting our poor decisions with the other bluefin species, no one had the bright idea to implement any type of regulations or management goals for this species. What’s worse is that upward of 95 percent of recent catches were juveniles that had not yet had the opportunity to spawn and contribute to the population. As such, it’s thought that only 100,000 or so Pacific bluefin remain and that the few adult cohorts responsible for the most spawning are reaching the end of their life span.


This chain of events has put regional fisheries bodies on their feet to halt overfishing and enact measures to begin rebuilding the stock. Unfortunately, the best they’ve been able to come up with is a plan to rebuild the stock to 6.4 percent of its virgin biomass by 2024. Even a 20 percent reduction in current harvest is estimated to give the population only a 35 percent chance of attaining a healthy biomass in 20 years.

Simply put, the current approach to fixing Pacific bluefin is untenable, and it is unconscionable that we’ve let this species reach this level of disrepair after the hard lessons learned with the other two. We need to put serious brakes on this fishery — perhaps even a complete moratorium on commercial harvest — until managers come up with a realistic and meaningful rebuilding plan.


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