Lobstermen in the Gulf of Maine have posted record harvests in recent years. But in the waters just south of Cape Cod, the situation is dramatically different. Lobster populations there crashed a decade ago and have not recovered, leaving lobstermen to face the potential closure of their fishery. In the second installment of our Cape Change series, we take a look at one of the most dramatic examples of how climate change is affecting New England’s fisheries.
Bob Usher / Flickr
Rising water temperatures are thought to be responsible for the collapse of lobster populations off the southern coast of New England.
Dick Allen was just a teenager when he dropped out of college to go lobstering with his brother-in-law nearly fifty years ago. They’d leave Westport and steam about 20 miles south to a place called Cox Ledge.
“You’d haul up a trap,” recalls Allen, “and there’d be these big lobsters that you’d have to struggle to get ‘em out of the traps.”
Over the decades, Allen watched those big lobsters disappear. By the late 80’s, he says, they were basically gone.
“It was like if you went into a town and you never saw anybody over 13 years old,” he says. “You’d say well something’s wrong here. And that’s the situation we had created in the lobster population in southern New England.”
Then, around 1998, the number of lobsters with an unsightly bacterial infection known as shell disease skyrocketed, and the population collapsed. Bob Glenn, Massachusetts’ chief lobster biologist, says shell disease is rarely fatal, so it probably didn’t cause the crash. But it does make it hard for lobstermen to sell their catch and, what’s more, it’s a symptom of a population under extreme stress. The question was what was causing the stress.
If you read
any of the news coverage of the recently released assessment of Gulf of Maine cod, you probably came away with three things.
Olga Caprotti / Flickr
- Fishermen are seriously questioning the new assessment (this was the focus of many mainstream media reports, not to mention a lot of political rhetoric).
- The 2011 assessment – which indicates that the stock has been overfished in recent years and stands no chance of reaching rebuilt status by 2014, as hoped – was a dramatic reversal from the previous (2008) assessment, which had suggested that Gulf of Maine cod was on the rebound. The discrepancy is one reason fishermen have greeted the report so skeptically.
- The revised assessment has put the fear of
God severe catch restrictions – if not this year, then in subsequent years – into New England fishermen. That’s another reason fishermen and politicians are subjecting the new numbers to such scrutiny.
What you probably didn’t get was a good explanation of why the two assessments were so different. Have cod stocks really evaporated in the past three years? Or was one of the assessments in error? And, if so, which one? A few articles referred to the fact that there were differences in the data and computer model used. But the details I crave were sorely lacking.
So I headed down to the other end of Woods Hole (it’s a grueling two-block walk) and spent a couple of hours with Liz Brooks and Mike Palmer, two of the scientists at the Northeast Fisheries Science Center who were involved in producing the 2011 Gulf of Maine cod stock assessment. Here’s what I learned.
A more nuanced assessment
There’s actually some good news to be found in the 2011 assessment. Both Brooks and Palmer are of the professional opinion that the actual status of the cod stock has not changed dramatically over the past three years, and that it definitely hasn’t crashed. In fact, they think it has been slowly rebuilding over the past several years – the latest three included.
This afternoon, the New England Fishery Management Council will hear first-hand about the dire 2011 Gulf of Maine cod assessment and take up the question of how to respond, specifically whether to recommend so-called ‘interim measures’ that might be more lenient than the dramatic cuts in catch limits mandated by federal law. In anticipation of that, 19 New England lawmakers have penned a letter to Secretary of Commerce John Bryson asking him to accept any recommended actions and to put serious effort into reviewing and improving the stock assessment process. In statements included in a press release about the letter, members of the Massachusetts congressional delegation also called for financial aid for fishermen if catch limits are slashed, and continued to criticize the catch shares management system and NOAA’s relationship with New England fishermen in general.
At the core of the debate over the new assessment is the fact that it contradicts two things: the previous (2008) assessment, and many fishermen’s sense of the stock’s health. Tension between fishery scientists, who like to rely on what’s known as fishery-independent data, and fishermen, who want their experience on the water to be given greater weight, is as old as fishery management itself (which isn’t really that old, in the big picture, but dates back a few decades anyway). The starkly contrasting assessments are more unusual – the result, it appears, of new data and some changes in the analysis process.
Both raise hard and valid questions: What is the best way to assess the size and health of a fish population? How close are we to that ideal? And how could we get closer?
While the Council is meeting in Portsmouth, NH this afternoon, those are the sorts of questions I’ll be taking up with two members of the cod assessment team here in Woods Hole.
NOAA Administrator Jane Lubchenco has denied a request for a new assessment of cod stocks.
Imagine you’ve been asked to redo three years worth of work in three months. Oh, and get a different result this time. I’m guessing you’d be grumpy. I know I would be.
Well, that’s basically what Senator Kerry and others pushing for a new assessment of Gulf of Maine cod were asking federal fishery scientists to do. So I can’t say that I was surprised to hear late last week that the request had been denied. Here’s the (extremely brief) AP story:
BOSTON (AP) _ The nation’s oceans chief has turned down a request made first by Sen. John Kerry for a new assessment of the health of Gulf of Maine cod.
New data indicates cod is badly overfished, and fishermen now face ruinous cuts in their catch. The data has drawn skepticism from fishermen because it’s a reversal of a recent, optimistic study.
In December, Kerry asked for a new cod assessment that fishermen can trust.
In a reply earlier this month, National Oceanic and Atmospheric Administration head Jane Lubchenco said a new assessment can’t be done in time for managers to make decisions for the May start of the fishing year.
She also said the agency doesn’t yet have new data needed to move ahead with further assessments. She assured Kerry she is committed to helping fishermen.
While I’m sure some will label Lubchenco’s comments stonewalling, the kicker is it’s true. Fishery scientists spend months at sea conducting surveys, then combine that with a multitude of other data sources to generate their best estimate of a given fish stock’s size and health. That process can’t possibly be crammed into the three months remaining before the start of the 2012 fishing season.
The alternative, I suppose, would be to reexamine the existing data. But consider this: if such a reassessment did produce a different answer, would what amounts to another reversal really be more trustworthy? Or simply more convenient?
Dave Bard, Pew Environment Group
In honor of the 35th anniversary of the Magnuson-Stevens Fishery Conservation and Management Act, the legislation that mandates federal fisheries oversight, Pew Environment Group has produced an interactive timeline of fisheries management milestones. The emphasis is definitely breadth, not depth (don’t look for a detailed history of your favorite fish stock). But a brief perusal left me with three very strong messages.
The first might be summed up as “holy rollercoaster, Batman!” Fish stocks are being declared disasters left and right while seafood consumption is skyrocketing; there’s certainly no shortage of drama. And while thirty five years may seem like a long time for individuals, this timeline emphasizes just how short a time it really is in the big picture.
Which brings me to my next point: just how new science-based fisheries management really is. The first comprehensive report on the status of U.S. fisheries was produced a mere fifteen years ago. And it’s only now that we’re reaching the milestone of having management plans and catch limits in place for all U.S. fisheries.
But for all the ups and downs, all the eye-opening, jaw-dropping “you mean we haven’t been doing that all along?!?” moments this whirlwind tour could elicit, it ends on a distinctly optimistic note: we’re on the right track. We are keeping track of our fish stocks, making efforts to rebuild them and plan for their sustainable use. It’s not a perfect or painless process, by any stretch of the imagination (and anyone involved in the process – fisherman, scientist, or otherwise – would tell you as much). But it’s something, and that’s a lot more than many fisheries around the world have.
What is it with outgoing heads of NOAA’s Fisheries Service declaring success on ending overfishing? Eric Schwab – currently assistant administrator for Fisheries, but soon to be assistant secretary for Commerce – has issued a statement confirming that all U.S. fisheries will have catch limits in place in time for the 2012 fishing season.
Everyone – commercial and recreational fishermen, NGOs, Councils, Congress and NOAA – knew it would be a heavy lift to put accountability measures and catch limits in place for all federally managed fisheries. Five years ago this week the Magnuson Stevens Fishery Conservation and Management Act reauthorization was signed into law and required just that – catch limits for all federally managed fisheries. Well, 2012 is here and we are almost fully over the goal line. Yes, there are a few stragglers, but I can report that all federal fisheries will have catch limits in place in time for the 2012 fishing season.
You can read the full statement here.
Olga Caprotti / Flickr
Last January started with announcement by the outgoing head of federal fisheries science, Steve Murawski, that 2011 would be the year overfishing was ended in U.S. waters. What he actually meant was that 2011 was supposed to be the year by which sustainable, science-based catch limits were set for each and every fishery taking place primarily in U.S. waters.
So did it happen? WaPo’s Juliet Eilperin reports federal fishery managers are close.
Although NOAA didn’t meet the law’s Dec. 31 deadline – it has finished 40 of the 46 fishery management plans that cover all federally managed stocks – officials said they are confident that they will have annual catch limits in place by the time the 2012 fishing year begins for all species. (The timing varies depending on the fish, with some seasons starting May 1 or later.) Some fish, such as mahi mahi and the prize game fish wahoo in the southeast Atlantic, will have catch limits for the first time.
Having science-based catch limits for all U.S. fisheries will be a world first – an undeniably historic milestone worth celebrating. But before we get carried away with champagne and confetti, it’s worth remembering that catch limits aren’t necessarily a guarantee of no overfishing, even if everybody stays within the limits. After all, science-based catch limits are only as good as the science upon which they’re based.
The science of counting fish is notoriously difficult. I recently saw it described as being just like counting trees, except that you can’t see the trees and they’re constantly moving. And it gets worse. Based on the number and size of fish around today (coupled with knowledge about growth and reproduction), scientists have to estimate how many and what sizes of fish will be available for harvest in future years.
Even when done as well as humanly possible, stock assessments are tricky – and the scientists who produce them are the first to admit that. That’s why federal officials will continue to list 40 stocks as actively overfished until new assessments confirm that current catch limits are actually appropriate. That’s why Gulf of Maine cod has been added back to the ranks of the overfished, even though the fishery has been operating within its catch limits. And that’s why scientists are constantly working to develop newer and better technologies for counting fish.
In reality, establishing catch limits for all U.S. stocks is neither the end nor the beginning of anything. It is simply one more step along the way to sustainable fisheries.
Mark Kasianowicz / Massachusetts State House Photographer
Massachusetts' 'sacred cod' may be hanging by a string, thanks to a legacy of overfishing and a future made uncertain by climate change.
As if a new assessment questioning the health of Gulf of Maine cod stocks weren’t enough bad news for New England’s fishermen, Nature News this week reports on two new studies that suggest fish may be more susceptible to climate change – particularly impacts on ocean chemistry – than previously thought.
It’s been obvious for some time that cod and other commercially important marine species are feeling the heat, literally. Surface water temperatures around New England have risen 2-4ºF in the past fifty years. Likewise, half of the three dozen marine species monitored by federal fishery scientists have shifted their distributions to match changing water temperatures. Most are moving northward and offshore, but others – like mackerel – have actually moved into shallower, near-shore waters.
The other carbon dioxide problem
Human-produced carbon dioxide emissions do more than raise ocean temperatures. They actually alter the fundamental chemistry of the ocean in a myriad of ways (scary thought, huh?). It all starts with one chemical reaction: water plus carbon dioxide makes carbonic acid. Add enough carbon dioxide, and the pH of the ocean starts to drop. So far we’ve added enough to shift the average pH of the ocean from 8.2 to 8.1 – a deceptively small numeric change that actually reflects a 30% increase in acidity. Thus, the term ‘ocean acidification.’
Sesame Street watchers may remember a little song that started “One of these things is not like the others …” Well, that’s Atlantic mackerel.
Atlantic mackerel are moving in response to rising ocean temperatures.
In 2009, researchers at the Northeast Fisheries Science Center in Woods Hole, MA announced that they were seeing the effects of rising ocean temperatures on commercial fish stocks. Half of the 36 commercially fished species routinely surveyed by fisheries scientists along the east coast were moving north/northeast and into deeper offshore waters to stay within their temperature comfort zones. Mainstays of New England fishermen, including cod and haddock, were on that list. Atlantic mackerel was one of just three species doing something different: moving northeast, yes, but moving into shallower inshore waters.
Mackerel doing its own thing
A new in-depth study of Atlantic mackerel distributions over the past forty years confirms that the species shifts with water temperatures – seasonally, annually, and over the long term. In fact, mackerel appear to be one of the species most sensitive to temperature changes.
Mackerel prefer waters between 5ºC and 13ºC. Those temperatures used to be found primarily off the mid-Atlantic coast, in a relatively thin strip of water along the edge of the continental shelf, wedged between cold coastal waters and the warm Gulf Stream. But the shallow waters atop the continental shelf aren’t as cold as they used to be. Atlantic mackerel can now be found ranging across the continental shelf from Maryland to southern New England.