Heat map showing warming waters in the Gulf of Maine over time. Credit: Pershing et al.
Climate change is preventing cod from rebuilding in New England. Many scientists and fishermen believe this, and a study released last week in Science by Dr. Andrew Pershing from the Gulf of Maine Research Institute and his co-authors provides new evidence to support this claim.
A brief history
Cod, an iconic species and a mainstay of New England fisheries, were overfished for decades, with catch levels peaking during the 1980s. In 2010, the fishery transitioned to the current quota-based management system under an Annual Catch Limit (ACL). Bringing cod under a fixed quota system should have ended overfishing and brought about recovery of the stock, but in recent years the biomass of Gulf of Maine cod has continued to decline, and was estimated in 2014 to be at just 3-4% of sustainable levels. Fishermen are catching fewer cod every year, and the quota is now so low that most fishermen actively try to avoid catching them. Yet despite these very strict catch limits, Gulf of Maine cod have not rebounded and the region’s fishermen are suffering devastating economic consequences. Read More
Fishing boats in Chatham, MA. Photo: Tim Connor
What every fishing port in New England has long feared has now come true: the iconic cod fish is disappearing in our waters. If our shared goal is to rebuild a sustainable fishery for years to come, then we need to better understand what is happening to the fish stocks. This calls for better science, which has been the subject of discussion for years.
A key foundation of better science is better catch monitoring. Inadequate catch data is the Achilles heel of the groundfish fishery in New England – particularly with cod – and the only way to improve this in a cost-effective way is through a comprehensive monitoring system that uses video technology. Read More
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. Read More
Recently, the impacts of climate change on fisheries have been in the news. The emphasis has been on the inability of scientists to explain how climate change is affecting fisheries or to fix the problems it seems to be causing. These include shifting distribution and abundance patterns of commercially valuable fish stocks – shifts that may leave fishermen stranded with very restrictive catch limits, even when they have been doing everything possible to protect and restore their stocks. These problems are being felt acutely in New England, where catch of some valuable stocks has been highly restricted to rebuild stocks depleted by overfishing – but they face even more restrictions as scientists find less fish in the water, possibly due to migrations induced by climate change.
A better scientific understanding of how climate change influences the distribution and abundance of fish is certainly needed, but that may be less important than the need for more flexible human institutions that can rapidly adjust to those changes. Read More
A number of scientific studies indicate that warming waters are affecting fish populations globally—and often in unpredictable ways. This finding is significant for fisheries management because as fish populations shift, whole ecosystems are changed. A recent study covering 40 years of data illuminates these changes in fish distributions and a Huffington Post article examines the research conducted to date and highlights the uncertain implications of this knowledge. The article extensively quotes our own scientist and Director of Spatial Initiatives, Jake Kritzer. Jake comments on the difficulty of making management predications without a complete understanding of how complex underwater ecosystems are shifting:
“It's an immensely complicated situation. You have climate change overlaying everything, and it seems to be changing the way everything works, which means we have a lot of problems. It's getting harder and harder to assess the stocks, to model them and understand their dynamics and predict what's going to happen. Because those models are based on years and years of experience reading fish stocks and studying them, they have been tested over a long time and they rely on a certain set of assumptions and conditions that now seem to be rapidly changing. Tools that have been fairly well established and worked well in the past just don't seem to be working as well anymore."
Read the full Huffington Post article: http://www.huffingtonpost.com/2013/05/17/ocean-climate-change-fishing-industry_n_3275505.html
Access the recent study published in Nature from researchers in British Columbia: http://www.nature.com/nature/journal/v497/n7449/full/497320a.html
Photo Credit: Natacha Hardy.
Alex Koeberle and Scituate Fisherman Frank Mirarchi
By: Alex Koeberle and Jake Kritzer
Following the hottest summer ever on record, the Atlantic coast was rocked recently by super storm Sandy, both stark reminders that climate change is increasing the frequency and severity of extreme weather events. This year had already seen effects of climate change take on a more prominent place in marine conservation debates. In July, renowned Australian ecologist Dr. Roger Bradbury argued that the fate of coral reefs is essentially sealed due to warming waters, rising seas, acidification and extreme weather (although other prominent voices were quick to counter such doomsday predictions). Closer to home, an effort to restore Atlantic salmon to the Connecticut River was ended after nearly a half-century, in part because changing ocean currents, temperature regimes and plankton production might be impairing the ability of salmon to survive at sea and migrate back to spawn.
It is not only salmon that are contending with effects of climate change in New England. The region is seeing sea levels rising faster than many other places around the globe, which threatens to drown salt marshes already struggling with excessive nutrient loads. Marshes help buffer coastal areas against storm surge, and provide vital nursery and feeding grounds for many important fish species. Ocean waters are not only rising but warming as well, one consequence of which has been a dramatic shift in the distribution of cod north of the primary fishing grounds in the western Gulf of Maine. Also, rainfall patterns are becoming increasingly erratic, altering salinity profiles and plankton production, which hampers productivity of species throughout the food web. Read More