Selected tags: Cod

Closed areas can decrease uncertainty in effects of climate change on New England Fisheries

Gulf of Maine Map

Photo Credit: New England Coastal Wildlife Alliance

As fishermen around New England will be the first to point out, this summer, much like last year, has been abnormal. The ocean waters were warmer and cod, haddock, and flounders—the mainstay of our fishing industry for centuries—are increasingly elusive. There’s plenty of blame to go around, including decades of mismanagement and overfishing, inexact science and a mismatch in abundance of certain predatory species. Looking beyond these factors, the impact of climate change on fisheries is another factor driving fish abundance that’s worth a hard look.

The level of carbon dioxide in the Earth’s atmosphere has now exceeded 400 parts per million, contributing to rising ocean temperatures. Some of the fastest increases in the last few decades have occurred in the Northwest Atlantic, and 2012 registered the largest annual increase in mean sea surface temperature for the Northwest Atlantic in the last 30 years.  

It is clear that climate change is disrupting New England’s fisheries right now; it is no longer an abstract, future scenario.

In the face of this evidence, fisheries managers need to factor in climate change alongside fishing effort and other elements when determining how to manage and rebuild fish stocks. The impacts of climate change can prevent fisheries management inactions from rebuilding fish populations, and conversely, excess fishing pressure can hinder the ability of a fish population to adapt to changes in climate. As I have written recently, a network of well-designed closed areas represents a promising management strategy to address the effect of climate change on fisheries.

Warming waters, shifting populations:

The mechanisms by which shifts in water temperature affect fish populations are not completely understood, but temperature driven changes have been observed in various species. Species’ response to climate change may be manifested as a shift in geographical distribution of the species, an expansion or contraction of the species’ range, or a change in depth distribution. Shifts in abundance are likely to be most apparent for species on the southern end of their range, and indeed shifts in fisheries distribution caused by warming waters are already taking place in the Northwest Atlantic. One study found a number of fish stocks in New England have shifted their center of biomass northward over the past 40 years.

Climate-driven shifts have been documented for cod in particular, one of the most economically, ecologically, and culturally important fish species in New England. Cod stocks on Georges Bank and in the Gulf of Maine are at the southern end of their range in the Northwest Atlantic. Temperature influences the distribution of cod in the region, and warmer water temperature has also been linked to a decline in productivity in the Gulf of Maine.

While climate change may be affecting iconic species in New England fisheries, other species may also be shifting their distribution north to areas where they are not typically found. Several news articles in local media outlets this summer featured fishermen who described the changes they’ve witnessed in the distribution of fish species. Fishermen in Maine have seen increasing numbers of black sea bass and longfin squid – species not traditionally seen in the Gulf of Maine – while fishermen in Rhode Island are catching warm water species like cobia and Atlantic croaker.

Finding management solutions to uncertain changes:

The New England Fishery Management Council is currently working to design a new network of closed areas in the region, which would build resilience in the fishery by providing protection for fish, as they shift their distribution and as they adapt to a changing ecosystem, thereby protecting fishermen’s businesses in the long-term.

Closed areas can protect the territory most critical to the productivity of target fish species, including important but vulnerable habitats, areas important for foraging and areas that harbor critical life stages like large spawners and juveniles. Refuges from fishing pressure can provide further resilience for fish species faced with a changing environment and a well-designed network of closed areas provides important stepping stones for fish species shifting their distribution in response to warming waters.

One way to increase resilience to climate change is to rebuild the population structure for overexploited fish stocks. Fishing pressure typically targets the largest (and oldest) fish. However, large, old females are typically more successful breeders, producing a much larger number of healthy larvae, and spawning more frequently than their smaller counterparts. Closed areas designed around known spawning grounds or other areas where these large females congregate can preserve a population of older, larger fish within the stock, reducing their exposure to fishing pressure and allowing them to reproduce and contribute to stock rebuilding.

Climate change needs to be considered when designing properly functioning closed areas, understanding that both fish and fishing effort may shift as a result of environmental change.

Uncertainty is inherent in both the marine ecosystem and our management of fisheries, and creating closed areas can ensure some level of insurance against this uncertainty.  A closed area network for New England’s fisheries should be broadly distributed throughout the region to provide refuges to fish, particularly as stocks shift northward from their traditional areas of abundance. A well-designed network of linked closed areas can allow species distribution to shift in response to climate change, but remain at least partially protected. This will be important not only to fish but to fishermen, creating the resiliency needed in a healthy fishery to support the long-term interests of the fishing industry.

This closed area network can provide resilience to climate change in the near term, and can be adapted to meet changing conditions as species shift.  The Council needs to consider climate change when making decisions about developing this closed area network.  They should not miss the opportunity to take a positive step in the direction of managing for a changing climate.

Dr. Sarah Smith is a member of EDF Ocean's Spatial and Ecosystems Initiatives team

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Disaster Funds and Cod Problems: Setting the Record Straight about Fisheries in New England

Cod

Photo from NOAA

New England has received a lot of media attention recently about the fisheries disaster declared by President Barack Obama. The precipitous decline in groundfish in New England waters has created an imminent need to help fishermen and fishing communities that depend on stable healthy fish populations.

It is important to dispense with false rumors and to set the record straight.  There is an effort on the part of some to claim that catch shares are somehow responsible for the New England groundfish population declines. To claim this is to suggest that fishermen have exceeded their catch limits and are not following the rules. This is simply not true. In fact, sector fishermen have been working hard to stay under their catch limits, and in some cases remain well below these limits.

In reality, the disaster declaration was based on the fact that there are changes happening in the ecosystem that are impeding the rebuilding of fish populations.  We are forced to confront the frightening reality that fishing is changing in part because our oceans are changing.  We are dealing with a resource problem, not a management problem. Read More »

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Charting a Course for Gulf of Maine Cod: Part II

Atlantic cod

Atlantic Cod; Photo Credit: NOAA

Yesterday, I recounted the recent history of assessments of the Gulf of Maine (GOM) cod stock that has led to a looming crisis for many New England fishermen, and the management response underway in the form of emergency action.  Today, I discuss two major goals that will most effectively use the time before us to potentially change our understanding of cod status, and avoid or minimize socio-economic hardship.

Expand our scientific perspective
Before the 2011 assessment had even been reviewed, a barrage of criticisms began to be levied.  To be sure, many decisions made during the assessment could have gone a different direction, including data to include or exclude, values for key parameters, and determination of reference points.  Renowned ecologist E.O. Wilson once observed that ecology is far more complex than physics, and fisheries science is a close cousin of ecology.  There are few universal rules for how to assess fish stocks, and the discipline relies heavily on experience, professional judgment, vigorous debate, peer review, and trial and error.  The GOM cod assessment was not lacking in any of those elements.  In my view, the assessment was done right, was done well, and should be commended for achieving what it set out to do.  Gerrymandering the assessment to get a more favorable outcome is both bad practice and bad policy. Read More »

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Charting a Course for Gulf of Maine Cod: Part I

Atlantic cod

Atlantic Cod; Photo Credit: NOAA

By now, most people concerned with fisheries management in New England, and in fact many others across the country, are aware of the difficult situation unfolding around the Gulf of Maine (GOM) cod stock.  For those who are not, a stock assessment completed late in 2011 drastically altered our perception of the stock from the last assessment completed in 2008, and suggests that the resource is in much worse shape than we previously thought.

Actually, in many ways the 2011 assessment tells a story similar to the 2008 assessment:  Biomass reached all-time lows during the 1990s, but then approximately doubled by 2001.  Thereafter, biomass dipped again to another low point in the mid-2000s, before climbing again toward the end of the 2000s.

The critical difference between the two assessments lies in the pace of rebuilding since the recent low in the mid-2000s.  The 2008 assessment suggested that the population was increasing extremely rapidly, with growth of more than 200% from 2005 to 2007.   In doing so, it had exceeded the overfishing threshold, and was well on its way toward the rebuilding target biomass that would produce the maximum sustainable yield on a continuing basis. Read More »

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First Woman Recipient of Nobel Prize for Economics, A Key Player in Ending the Race for Fish

Elinor Ostrom, who shares this year's Nobel Prize for Economics, laid much of the intellectual foundation for EDF's current work with fishery cooperatives. Catch shares evolved from common property theory and empirical observations that, under certain conditions, resources such as fish, water, or pasture land tend to be overexploited when property rights are not clearly delineated. Ostrom's research shows that resource users can develop cooperative methods to avoid overexploiting resources and dissipating wealth through competition. 

While some say that this idea "challenges" the conventional wisdom, research conducted by EDF's Ocean Innovations suggests that competitive and cooperative dynamics depend on scale and the attributes of the communities themselves. Our results will soon be published in the Bulletin of Marine Science. This research and our experience with fishermen on the water motivates our work with the Cape Cod Commercial Hook Fishermen's Association and the Morro Bay Community Based Fishing Association, two pioneering efforts to cooperatively manage fisheries. 

We believe that cooperative approaches can complement catch shares, which often apply at larger scales and to more industrial, less socially cohesive fishing communities. Such approaches are also broadly applicable in many developing countries, where social values are emphasized over individualism and economic gain, and where legal and political structures facilitate the delegation of resource use privileges to groups.

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