UMaine leads $3 million study on how warming Arctic affects lobsters in New England
Richard Wahle, director of the university’s Lobster Institute and professor in the School of Marine Sciences, is spearheading the project, dubbed the NNA Lobster Network, joined by 18 other researchers from UMaine, the Gulf of Maine Research Institute, Columbia University, Florida State University and Memorial University of Newfoundland.
Building on long-standing partnerships
with the fishing industry, government and academic organizations, the team will
investigate how climate-induced Arctic change alters lobster abundance and
distribution from coastal Rhode Island to Newfoundland.
NSF funded the study not only as part of its NNA initiative, but also as one of its 10 Big Ideas. The NNA Lobster Network will support investigations into the influence of past and future climate and management scenarios on various physical, biological and socio-economic conditions at different scales; all through cross-sector and cross-border partnerships.
The results of this project could help improve models for lobster population distribution forecasts, as well as an understanding of the economic dependence of coastal communities on this fishery and, therefore, their vulnerability to future change.
Researchers hope that new data on Arctic ice melt trends will give the team unprecedented lead time to anticipate ocean ecosystem changes that influence lobster distribution and abundance.
Resulting
forecasts and scenario analysis tools will provide crucial information for
fishermen and other stakeholders in this iconic fishing industry that netted
$725 million in 2021 in Maine alone, according to Maine’s Department of Marine
Resources.
“The project is well timed to meet the urgent need to understand
the increasingly apparent links between a rapidly warming Arctic and the rapid
ecosystem changes in the Gulf of Maine, the Gulf of St. Lawrence, their
fisheries and communities that, in some cases, are perilously reliant on the American
lobster,” Wahle says.
Arctic warming poses several threats to the world’s oceans. Melting glaciers, icebergs and ice sheets are increasing sea levels and altering ocean circulation, a crucial driver of heat movement around the globe that, when disrupted, can increase or decrease water temperatures and cause unpredictable weather and climatic changes. Additionally, thawing permafrost in the Arctic is releasing more carbon into the atmosphere.
The NNA Lobster Network aims to use the latest information and models of changing Arctic conditions to generate forecasts on how ocean circulation and the lower latitude coastal marine ecosystem of the Northwest Atlantic will change in future decades out to 2050.
In turn, this information will be used to update and geographically expand existing larval lobster transport and population dynamic models initially developed for the Gulf of Maine. In the end-to-end analysis, economists will use this information to evaluate impacts of changes in the lobster resource on fishing fleet dynamics, operations and economic outcomes for the fishery.
Project social scientists will build on quantitative climate resilience indicators that are already under development for Maine and expand their reach to lobster communities in other parts of New England and Atlantic Canada.
Long-standing partnerships with the
fishing industry and government agencies will help provide the ground truth data
and feedback needed to both validate model products and make them useful to
stakeholders.
Previous research by scientists from UMaine and other institutions have discovered that when it comes to the lobster fishery, there are winners and losers in a warming ocean, Wahle says.
For example, rising temperatures across the Gulf of Maine, which is warming faster than the vast majority of the world’s oceans, caused lobsters to shift farther north over the years to keep pace with their northerly migrating cold-water habitat.
As a result, lobster
fisheries in southern New England have experienced significant die-offs and
financial loss. At the same time, rising temperatures have had favorable
effects on the Gulf of Maine’s lobster fishery over the past decades, although
continued warming now may threaten its viability.
Just as the influence of the cold, nutrient-rich Labrador Current from the north is diminishing, the warm, salty and nutrient-poor Gulf Stream waters are being felt more strongly, dramatically altering the productivity of the Gulf of Maine ecosystem.
Researchers hypothesized that these climate-induced ecosystem changes, along with the adverse effects of stressfully warm summer temperatures, have caused a decline in larval lobster survival that ultimately results in smaller harvests.
This work is also
relevant to understanding the changing abundance and distribution of members of
the ecosystem other than the lobster, from the tiniest plankton to the iconic
Atlantic cod, herring and even the endangered North Atlantic right whale.
To determine how changes in the Arctic affect lobster populations in the Northwest Atlantic, Wahle and his team plan to create a climate vulnerability assessment that focuses on the lobster fishery’s northward range shift as the ocean warms.
They also will develop a coupled
atmosphere-ice-ocean-ecosystem model to examine how changes in ocean
circulation and the Arctic cryosphere, the frozen parts of the region, affect
fishery and ecosystem productivity in New England and Atlantic Canada.
Researchers will use existing field datasets, including some co-produced with
the fishing industry, to validate their model.
“The lobster fishery is a heritage industry that is essential to
the island and coastal communities of Maine,” says Marianne LaCroix, executive
director of the Maine Lobster Marketing Collaborative. “Knowing more about
future climate conditions in the Gulf of Maine will allow the fishery to adapt
practices so that they can see continued success.”
“A unique aspect of the NNA Lobster Network is that it capitalizes
on long-standing cross-border collaborations among scientists, fishers and
government agencies in the U.S. and Canada to develop tools to analyze likely
scenarios and forecast future climate impacts on our coastal communities that
are now so economically dependent on the lobster fishery,” says project partner
professor Rémy Rochette of the University of New Brunswick.
Wahle has been conducting lobster and other marine science-related research in the Gulf of Maine since the late 1980s. He joined UMaine faculty in 2009 after 15 years as a research scientist at Bigelow Laboratory for Ocean Sciences. He became director of the Lobster Institute in 2018.
In 1989, Wahle
founded the American Lobster Settlement Index, a scientist-industry
collaborative that monitors the annual pulse of juvenile lobsters that settle
in coastal nurseries at over 80 sampling sites from Rhode Island to Atlantic
Canada.
Wahle is one of many UMaine faculty members conducting research involving the Arctic and the implications of its climate-induced warming. In 2018, the UMaine Arctic Initiative was formed to build on their work and enhance collaboration in the campus community and with outside stakeholders. The Lobster Institute’s mission is to foster research and communication toward a sustainable and profitable lobster fishery in the U.S. and Canada.