Marine Heatwaves and Highly Migratory Species Hotspots of Change

The Fisheries and Climate Toolkit (FaCeT) is an ongoing project with funding from NASA’s Ecological Conservation program and the Northeast Regional Ocean Council (NROC). This work addresses a data gap for highly migratory species and pelagic ecosystems that had been identified and often discussed by researchers and other experts working with NROC and the Regional Wildlife Science Collaborative (RWSC). The FaCeT team is focused on co-developing a wide range of data products and their visualizations designed specifically with and for ocean managers based on an understanding of changing ocean conditions. The FaCeT team recently presented their work to the RWSC Habitat & Ecosystem Subcommittee (see December 11 2025 meeting materials).

Above: A map predicting the number of highly migratory species that will lose habitat in areas off the Mid-Atlantic coast in summer months.

These six map layers show the predicted gain or loss of habitat suitability for 12 highly migratory species under future ocean conditions during summer (monthly average of June, July, August), winter (monthly average of December, January, February), and annually (12-month average). The following can all be found in the Marine Life theme by clicking on the “Highly Migratory Species - Hotspots of Change” dropdown:

• Number of Species Gaining Habitat – Summer
• Number of Species Gaining Habitat – Winter
• Number of Species Gaining Habitat – Annual
• Number of Species Losing Habitat – Summer
• Number of Species Losing Habitat – Winter
• Number of Species Losing Habitat - Annual

The new products build on models added to the Portal in 2025 depicting past and future potential habitat suitability for bigeye tuna, bluefin tuna, blue shark, yellowfin tuna, shortfin mako, and swordfish. Six additional species used to derive the latest habitat suitability products will be soon added to the Portal: albacore tuna, skipjack tuna, porbeagle shark, white marlin, blue marlin, and sailfish.

Above: A map showing sea surface temperature anomalies in January of 2024.

Marine Heatwaves (MHWs) are short-term extreme warming events, typically reported as deviations or anomalies from average temperatures. Anomalous water temperatures from MHWs are leading to a wide range of impacts such as mass mortalities and strandings of marine species, shifts in species distributions, and alterations to ecosystem structure and function. MHW events vary in intensity, spatial extent, and duration as they are driven by a range of complex oceanographic and atmospheric processes.

The following maps, which can be accessed in the Oceanography theme, depict monthly MHWs for several example years that highlight the variability in heatwave conditions in the Atlantic Ocean. Users can automatically animate or manually toggle through the monthly views for each year using the slider tool in the Active tab.

• Sea Surface Temperature Anomaly, Monthly Slider 2024 (January - June)
• Sea Surface Temperature Anomaly, Monthly Sliders (2012, 2014, 2022, 2023)

The maps show a sea surface temperature anomaly contour that outlines the spatial area under marine heatwave conditions for each month. The MHW contour outlines pixels experiencing a monthly sea surface temperature anomaly above the 90th percentile of the seasonal threshold for that pixel (2000-2020 climatological baseline).

• Fisheries and Climate Toolkit
• Nima Farchadi et al., 2024. Marine heatwaves redistribute pelagic fishing fleets. Fish and Fisheries 25, 602–618. https://doi.org/10.1111/faf.12828
• Camrin D. Braun et al., 2023. Widespread habitat loss and redistribution of marine top predators in a changing ocean. Science Advances 9, eadi2718. https://doi.org/10.1126/sciadv.adi2718
• Nima Farchadi and Laura H. McDonnell et al., 2025. Marine heatwaves are in the eye of the beholder. Nature Climate Change 15, 236-239. https://doi.org/10.1038/s41558-025-02257-6