Understanding Climate Hazards

Climate hazards to fisheries systems.

Climate change poses a range of hazards to fisheries systems in the Northeast US, leading to challenges affecting fish stocks, fishery operations and shoreside infrastructure both now and in the future. Understanding current trends as well as potential future changes can help to prepare fisheries and communities.

In brief:

  • Climate change is altering the physical and chemical—and, consequently, ecological—characteristics of our oceans.
  • Warming, sea level rise, and ocean acidification are key challenges to fisheries, affecting species productivity and availability as well as threatening important waterfront infrastructure.
  • Below are some of the key current and future regional trends in these hazards, and links to additional helpful further resources.

Hazards and exposure

Natural or human-caused physical events can impact lives, livelihoods, ecosystems, and society. Climate change is altering the frequency and severity of these events, and some places or groups of people may experience impacts differently from others.

Climate science uncertainty and scenarios

Projecting future climate trends is challenging and inherently involves some uncertainty. This uncertainty can stem from data collection and the methods, analyses and models used to interpret data and make projections. Additionally, human choices about greenhouse gas (GHG) emission reduction levels and timelines will affect future climate conditions. Different scenarios are therefore used to represent possible futures, and projections based on these scenarios often have a range (derived from various computer models) provided to help quantify the levels of associated uncertainty. Importantly, uncertainty should not prevent us from preparing for future impacts.

The Intergovernmental Panel on Climate Change (IPCC) uses scenarios, which are representations of potential futures. IPCC scenarios combine Shared Socioeconomic Pathways (SSPs) and Representative Concentration Pathways (RCPs). SSPs describe different global social and economic development patterns and trends and RCPs detail different atmospheric GHG concentration levels (driven by different emissions levels), land use patterns, and other climate drivers. The IPCC 2021 report (section 1.6) includes more details about SSPs and RCPs.

Modeling results that we present later on this site use the SSP5-8.5 scenario. This scenario represents a future with continued rapid economic growth, which limits GHG emissions reductions yet facilitates adaptation, resulting in a 3.2°C (5.8°F) increase in median global sea surface temperature by 2100 relative to pre-industrial (1850-1900) (IPCC WG1 Interactive Atlas).

Climate Hazards

A range of climate hazards affect fisheries, and we outline some of these hazards below.

Ocean warming

The waters on the Northeast Shelf are warming rapidly–nearly three times faster than the world’s oceans since 1982. Along with this warming trend, marine heatwaves have become more frequent and intense. For the Northeast Shelf, by 2050 under SSP5-8.5, sea surface temperatures are projected to increase 1.0 - 3.5℃ (1.8 - 6.3℉) above those experienced during 1976-2005. Under the same scenario, temperatures are projected to warm 3.0 - 5.5℃ (5.4 - 9.9℉) by the end of the century.

Warming projections for this area under different climate scenarios are available via NOAA’s Climate Change Web Portal. You can find seasonal and annual warming updates for the Gulf of Maine here.

A timeseries that shows the continued increase in SST from 1982 to 2023.
A timeseries of annual average sea surface temperature anomalies for the Northeast US (solid black line) from 1982 through 2023. Long-term trendlines for the Northeast Shelf (blue) and the entire globe (green) show how much more quickly the Northeast Shelf is warming compared to the rest of the world.

Sea level rise

Northeast US sea level has risen about 10 inches over the past 100 years (1920 – 2020), with about half of this rise occurring in the past 40 years due to thermal expansion from warming water and growing meltwater contributions from glaciers and ice sheets. If sea level rise continues along its current trajectory, 2050 sea level will be 1.3 ft (0.39 m) higher than the sea level in 2000, with a possible range of 0.9 – 2.3 ft (0.27 – 0.69 m). By 2100, sea level could rise from 1.5 – 8.1 ft (0.45 – 2.47 m). This large range is due to uncertainty in human greenhouse gas emissions and the response of ice sheets to warming. These scenarios are from the 2022 U.S. Interagency Task Force sea level technical report, which are consistent with IPCC projections.

A graphic that shows how much sea levels have been rising.
Sea level change for the Northeast from observed (red line) data, and projected median and likely range for future scenarios (colored lines). Graphic and information derived from NASA Interagency Sea Level Rise Scenario Tool.

Ocean acidification

Ocean waters in the Northeast US, particularly in the Gulf of Maine, are also sensitive to acidification, which occurs as they absorb atmospheric carbon dioxide. Changes in carbon dioxide uptake alter the seawater chemistry, ultimately resulting in lower pH levels. The acidification effect is compounded in coastal waters, where freshwater inputs and nutrient loading further exacerbate the effects of acidification.

Ocean acidification is a concern for shell-forming organisms, such as clams, scallops and oysters, which absorb calcium and carbonate from seawater to build their shells. Aragonite is a specific form of calcium carbonate that is needed in this process. Much of the Northeast US is experiencing suboptimal aragonite saturation levels – meaning they are below 1.5 Ωar for at least a portion of the year. Future projections indicate continued declines in aragonite saturation and suboptimal saturation levels for a longer portion of the year. These effects will be most severe in nearshore coastal waters, but they are projected to expand to offshore waters, including most of the Gulf of Maine surface waters, by mid- to late-century.

This is a map of ocean acidification conditions in the northwest Atlantic.
Map showing minimum monthly averaged sea surface aragonite saturation state. Map obtained from NECAN (linked in the useful resources section), based on data from Signorini et al 2013. Read the associated study by Gledhill et al 2015.

Impacts on fisheries

Ocean warming, rising sea levels, and ocean acidification will have a variety of impacts on fisheries.

  • Warming can influence the geographic distribution and population abundance of target species. Acute heat events may threaten the survival of animals that live in shallow waters; these same areas are threatened by deoxygenation, as warm waters cannot hold as much oxygen as cooler waters.
  • Warmer oceans enable storms to intensify and last longer, which curtails fishing opportunities, threatens safety at sea, and can damage vessels and shoreside infrastructure.
  • Sea level rise and higher storm surges pose risks to land-based infrastructure that supports marine fisheries, such as docks, shoreside businesses, and roads.
  • Acidification threatens shell-forming organisms, whose shells may dissolve in more acidic waters. This may result in changes in availability of these species for harvesting.

Useful resources and tools

Understanding Climate Impacts on Fisheries

Understanding how climate hazards impact fisheries systems is critical for adaptation planning.

Staff Contact

If you have any questions or concerns, please contact Dr. Kathy Mills.

Kathy Mills, Ph.D.
Kathy Mills, Ph.D. Senior Scientist (207) 228-1657 [email protected]

Project Sponsor

The information within this site was funded and supported by the NOAA Climate Program Office through the Coastal and Ocean Climate Applications program under awards NA15OAR3410120 and NA19OAR4310384.

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