Sunday, November 9, 2014
BEATING UP ON BLUEFIN
Bluefin tuna have fascinated me since 1960 when, at the age of six, I walked the docks at Provincetown, Mass. with my parents, and saw giant tuna—fish that seemed impossibly large to a kid used to flounder and snapper blues, who thought that a codfish was big—bulking silver and huge in the cockpits of charter boats returning from sea.
As I grew older, and could (barely) afford my own trips on charters, bluefin were one of the first fish that I sought.
Once I bought my first (barely) offshore-capable boat, bluefin were always in my sights.
Years passed, and boats came and went. I caught plenty of bluefin, and killed at least my share. I fished tournaments, and put my anglers on tuna that won them first prize.
And the bluefin steadily dwindled.
At first you could write it off to water temperature, a lack of bait or to that conveniently mysterious “cycle.” But by the mid-1990s there was no way to doubt that the bluefin population was under serious stress.
So we stopped killing bluefin, but catch-and-release was still on the agenda. We beefed up our gear to prevent tuna “burnout,” but still pulled feathers and cedar jigs and various plastics through Long Island’s ocean, seeking and finding what remained of a once-robust stock.
But we even stopped that back in 2006, when the big 2003 year class became “school” bluefin big enough for anglers to target.
At first, we avidly joint the fleet of boats that ranged from flyfishing skiffs to big, rigged-out sportfishermen that jumped on the little tuna every time they turned up anywhere along the coast. That changed on one July morning that found us pulling lures a dozen miles south of my inlet, hooking up bluefin almost as fast as we could get our lures in the water.
All was going well until a fish blew up behind a Green Machine bar, coming in from straight behind the trailing lure and swallowing it so deep that not even the head poked out of the little bluefin’s mouth.
Catch-and-release wasn’t an option with that one.
So we bled the fish and put it on ice, pulled the lines and went in; the limit was one bluefin per boat, and we didn’t want to risk injuring another fish that would have to be returned to the water to die.
But whatever we did, a lot of bluefin got killed. Despite the restrictive bag limit, quite a few boats took plenty more and, when anyone mentioned the law, denied that the fish were bluefin at all. They said that taking three yellowfin per angler was legal, and “Look at the f***ing fish. They got yellow fins…”
And there were far too few enforcement folks around—working for the state or the feds—to tell such anglers that they were mistaken.
Maybe that’s why so many of the bluefin that those anglers caught ended up being sold at the back doors of sushi shops, markets and restaurants…
It was a pretty sad scene, and quite honestly, I had no desire to be a part of it. When that small bluefin died on the deck of my boat, I decided that it would be the last one, until the stock showed signs of recovery.
I knew that it was a futile gesture, and that one person’s actions would have no effect on the whole, but even so, sometimes doing what you think is the right thing is reason enough.
But, God, I was alone…
As the 2003s grew older and larger, anglers continued to kill them. Law enforcement didn’t get any better, and violations continued apace.
Even the simple requirement that anglers report their catch to federal managers was largely ignored; the National Marine Fisheries Service estimated that about 20% of anglers called in as required.
The sushi shops’ business continued to thrive…
Now, the 2003s have reached breeding size (generally believed to begin between 8 and 12 years old, although a recent paper argues for a younger age), which also makes them large enough for legal commercial harvest, and it appears that the International Commission for the Conservation of Atlantic Tunas may start piling on.
After all, who wants to have a bunch of old, fecund bluefin around..?
Up in Massachusetts, commercial tuna fishermen are having their most successful season in years. A lot of the fish that they’re catching are 2003s.
Current regulations let them kill quite a few. However, the ICCAT’s annual meeting begins tomorrow, and next year, they might get to kill more.
One of the goals of the United States’ delegation is to
“Adopt a two-year catch limit for western Atlantic bluefin tuna that is in line with the science advice and supports the goals of the rebuilding program by avoiding overfishing and allowing continued stock growth.”
That sounds good on paper, and we can only hope that it translates into maintaining quotas at moderate levels so that substantial numbers of the 2003 year class can survive and remain an important component of the spawning stock.
However, other nations have already made their intent to kill more tuna clear.
“the stock has grown substantially in recent years and could support a moderate quota increase.”
The fact that Stanek qualifies his statement by using the same sort of language embodied in the United States’ goals, saying
“Canada will continue to advocate for all management decisions to be based on the best available scientific information to ensure that these economically important fisheries remain sustainable,”
provides little comfort, and might even cause the U.S. statement to be viewed with suspicion.
That is particularly true given how U.S. commercial fishing groups are spinning a recent bluefin tuna stock assessment. For example, the American Bluefin Tuna Association has triumphantly declared that
“the best available science now indicates a stunning increase in abundance of [bluefin tuna] on both sides of the Atlantic…
“Consequently, the SCRS report stated that an increase in quota, up to 2,250 mt from its presently level of 1,750 mt, is consistent with ongoing ICCAT management objectives. The report states that spawning stock biomass is presently 2 ¼ times greater than necessary to sustain a quota of 3,050 mt each year, going forward…”
Congressman Walter Jones jumped on the “spin the bluefin” bandwagon, issuing a press release that said
“…last month ICCAT scientists released new data showing that western bluefin stocks are more than twice the size suggested in previous assessments and are now more than rebuilt. They also concluded that the western Atlantic quota could be increased from the existing 1,750 metric tons to up to 2,250 metric tons without hurting the stock. In a letter sent today, Jones urged U.S. fisheries administrators to “follow the science and do all you can at the November ICCAT meeting to secure an increase in the western bluefin quota to 2,200 metric tons.”
However, an objective reading of the facts doesn’t quite support such exuberance. Nor does it support the position of ABTA or Congressman Jones.
“A key factor in estimating [maximum sustainably yield]-related benchmarks is the highest level of recruitment that can be achieved in the long term. Assuming that average recruitment cannot reach the high levels from the 1970s, recent [fishing mortality] (2010-2013) is 36% of FMSY and SSB2013 is about 225% of SSBMSY… [emphasis added]”
Thus, the ABTA/Jones position is justifiable, but only if one makes the most pessimistic assumptions about future bluefin spawning success.
Addressing that very point, the assessment clearly states that
“In contrast, estimates of stock status are more pessimistic with respect to spawning biomass if a high recruitment potential scenario is considered, with F=88% of FMSY and SSB2013=48% of SSBMSY.”
That’s a pretty big difference.
The assessment notes that the low recruitment scenario results in an “improved fit of assessment outputs” in the population model, but that both the low-recruitment and high-recruitment scenarios are
“plausible (but not extreme) lower and upper bounds on rebuilding potential.”
If the quota is increased as proposed by low-recruitment advocates such as the ACTA and Jones, no long-term increase in population size is likely to occur. Instead, the population will decrease in the short term, but by 2019 should equal 2013 levels.
On the other hand, if the high-recruitment scenario is the more accurate of the two, and recruitment increases as the population grows larger, an increased quota will result in the population failing to meet the rebuilding target by the 2019 deadline.
In the end, the only way to find out which of the scenarios is correct is to keep quotas low, preserve as much of the 2003 year class as one practically can, and see what happens.
If populations continue to rebuild, the high-recruitment scenario will have justified itself, even if populations fall a little short of 1970 (the base year) levels.
On the other hand, if the population remains constant, even after the relatively strong 2011 and 2013 year classes enter the spawning stock, the low-recruitment advocates can justifiably say “We told you so” and quotas can be increased.
However, if we increase quotas now, before all of the evidence is in, we may never know just what we have missed, or how badly we’ve cheated ourselves.