The Gulf of Maine Predicted to Experience Cooler Bottom Water Temperatures in 2025

The Gulf of Maine, known for being one of the fastest-warming ocean regions in the world, is set to undergo a significant shift in bottom water temperatures this spring and summer. A new experimental outlook developed by NOAA scientists indicates that the region will experience cooler bottom water temperatures compared to previous years.

Initial observations of this cooling trend were reported by NOAA’s Northeast Fisheries Science Center and detailed in the NOAA Fisheries 2025 New England State of the Ecosystem Report. Data suggests that since late 2023, the Northwest Atlantic has witnessed a decrease in bottom water temperatures due to the southward movement of the eastern portion of the Gulf Stream and a potential increase in Labrador Slope and Scotian Shelf water entering the system.

Researchers anticipate that the Gulf of Maine could be 0.9-1.8 degrees Fahrenheit cooler this summer, which may have implications for marine life in the region. Bottom water temperatures play a crucial role in the productivity of groundfish species like cod, haddock, and pollock, as well as lobster, a key fishery in the northeast.

The commercial fishing industry in New England, which contributes significantly to the regional economy, is likely to be impacted by these changing ocean conditions. With over 280,000 jobs supported by the industry and $1.4 billion in revenue generated in 2022, any shifts in marine ecosystems can have far-reaching economic and social consequences.

NOAA scientists have developed a companion longer-term outlook that suggests the influx of cooler deep waters may continue to moderate warming in the Gulf of Maine for the next few years. Ongoing monitoring is essential to validate this prediction and understand the long-term implications for marine species and fisheries.

Through the Changing Ecosystems and Fisheries Initiative (CEFI), NOAA Research is working on developing regional ocean prediction systems for all U.S. coastal regions and the Great Lakes. These systems will provide valuable information on ocean chemistry, plankton populations, and ecosystem changes to support sustainable fisheries management and coastal community planning.

The outlook for the U.S. East Coast, from the Gulf of Maine to the Southeast U.S. and Caribbean Islands, is based on predictive models like SPEAR and MOM6, which offer insights into ocean temperature forecasts and ecosystem dynamics. While the Gulf of Maine is expected to experience cooler temperatures, the Southeast U.S. and Caribbean regions are predicted to have moderately above-normal surface temperatures this spring and summer.

Overall, the evolving ocean conditions in the Gulf of Maine underscore the interconnectedness of marine ecosystems and the need for proactive monitoring and management strategies to ensure the sustainability of fisheries and coastal communities.

This illustration depicts predicted ocean temperature forecasts for 2025 for the northwest Atlantic issued by the Changing Ecosystems and Fishery Initiative. Credit: NOAA GFDL