The Northeast Shelf: A Changing Ecosystem

The U.S. Northeast Shelf large marine ecosystem supports a number of economically important fisheries and a wide variety of other important marine and coastal species, from river herring to marine mammals and sea turtles. The region has experienced rising ocean temperatures over the past several decades, along with shifts in the distribution of many fish stocks. Other expected climate-related changes include sea-level rise, acidification, and changing circulation patterns. These changes could impact marine resources, their habitats, their distribution and abundance, and the people, businesses, and communities that depend on them.  Understanding the impacts of climate change  is necessary to reduce these effects on marine life.

The Northeast U.S. Continental Shelf extends from Cape Hatteras, North Carolina to the Gulf of Maine and supports important and highly productive commercial and recreational fisheries. The coastal waters are strongly influenced by two major current systems: the Labrador Current flowing equatorward from the north and the Gulf Stream flowing poleward from the south.

Climate has a profound effect on life in the oceans. In the Northeast U.S. continental shelf ecosystem, drivers of climate change and variability are derived from both natural and human-related activities and contribute to physical, chemical, and biological variability in the ecosystem. The Northeast Fisheries Science Center has a variety of research and monitoring efforts that help track, understand, and forecast climate-related impacts on resources and resource-dependent communities. Over the last two decades, ocean temperatures in the Northeast have warmed faster than the global ocean. In particular, the Gulf of Maine has warmed faster than 99 percent of the global ocean.

Recent studies suggest that a large portion of this enhanced warming is caused by  human activity . The major component of human activity that contributes to climate change is the historical and continued emission of long-lived greenhouse gases: carbon dioxide, methane, and nitrous oxide. Since the beginning of the post-industrial era in 1750, atmospheric concentrations of these gases have increased substantially because of human activities. With such a dramatic change in the ocean environment, it is important to study the impacts in order to have a better understanding of the potential management needs of ocean resources.

NOAA has studied climate change for several decades. The majority of research on historical and projected climate change impacts to the Northeast U.S. continental shelf ecosystem has focused on species distributions. Most of these studies use the Northeast Fisheries Science Center’s fall and spring bottom trawl survey data to build species distribution models for fish, sharks, and invertebrates. 

Many species continue to shift northeast along the shelf and into deeper waters. This impacts what fish are available to catch, how much time and effort it takes to catch those fish, and who is responsible for managing human use of those species. In particular, fishery management measures based on historic distribution of a species may not have the expected outcomes if that species is changing when and where it occurs.

Although there are many different species that are affected by the changing climate there are three species of particular interest and concern-Atlantic cod, American lobster, and black seabass-as they are economically important species.  A study  using species distribution models from the Northeast Fisheries Science Center found that species ranges are projected to shift and contract within 60-80 years and were most extreme in Atlantic cod, American lobster, and black sea bass.

Changing ranges and species distribution is not the only thing changing in the northeast shelf ecosystem. The northeast shelf has had a significant change in thermal regime and extreme thermal events that have increased species diversity (moving species) and ocean productivity.  A study by Friedland et al . found that despite changes in niche overlap and rising temperatures, they observed an increase in productivity, and the only evidence of competition was the decline in body size principally among benthic species.

Regional action plans have been developed in each region by NOAA's science centers and regional offices. The plans respond to the growing demands for information on what’s changing, what’s at risk, and how to respond to climate-related changes in marine and coastal ecosystems. The plans are designed to increase the production, delivery, and use of scientific information needed to fulfill our mandates in a changing world.

The Northeast Regional Action Plan identifies priority needs and specific actions to implement the  NOAA Fisheries Climate Science Strategy  in the region over the next three to five years.

The Regional Action Plan’s goal is to increase the production, delivery, and use of climate-related information to help reduce impacts and increase resilience of the region’s marine life and resource-dependent communities.

A critical element of this Action Plan is partnerships. The challenges are great, the issues are complex, and resources are limited. Partnerships are essential. By working together, we can reduce the impacts of changing climate and ocean conditions on marine life and increase the resilience of these resources and the people, businesses, and communities that depend on them. NOAA Fisheries will work with partners to further develop regional action plans to identify strengths, weaknesses, priorities, and actions to implement the strategy in each region over the next several years.

Changes in the distribution and abundance of these and other species have affected where and when fishermen fish and what they catch, with economic impacts rippling into the coastal communities and seafood businesses. With better information on current and future shifts in fish stocks, fisheries managers and fishing industries can better plan for and respond to changing ocean conditions.

As southern fish species like black sea bass spread northward along the East Coast, they may provide opportunities for additional commercial or recreational fisheries. Changing conditions may also stimulate more opportunities for other marine-related businesses, such as fish and shellfish farming. Better information on when, where, and how marine resources are changing is critical to taking advantage of future opportunities and increasing the resilience of our fisheries and fishing communities.

By using partnerships and the best available science, we will be prepared for any changes that may happen to the northeast shelf.