Marine ecosystems are subject to a variety of stressors in the Greater Atlantic region, which includes the coastal states of Maine, New Hampshire, Massachusetts, Rhode Island, Connecticut, New York, New Jersey, Delaware, Maryland, and Virginia. Some of the strongest impacts on fisheries will be from warming air and sea temperatures, prompting shifts in the ranges of many commercially important species. For example, warming waters off the coasts and the continental shelf of the Northeast have been associated with redistributions and shifts in the ranges of many traditionally fished species (EAP 2009). Of the 82 fish and invertebrate species analyzed in the Northeast Fish and Shellfish Climate Vulnerability Assessment (NOAA 2016), over 60% exhibit high to very high potential for future changes in distribution, including shifts into and out of the Northeast shelf ecosystem (Hare et al. 2016). For species at the southern end of their range, increased ocean temperatures may lead to range contraction and/or mortality (Nye et al. 2009).

Warming oceans are also likely to lead to disruptions in spawning activity and recruitment for many fish species, as well as increases in toxic shellfish parasites (Najjar et al. 2000). In areas such as the Chesapeake Bay, some species (e.g., blue crab [Callinectes sapidus], oysters, Atlantic croaker [Micropogonias undulates]) may benefit from warmer temperatures due to increases in overwintering survival, though these benefits may be offset by increases in invasive predators and pathogens (Najjar et al. 2010).

Sea level rise and ocean acidification will also stress fisheries in the Greater Atlantic. The Northeast has experienced higher rates of sea level rise than the global average over the past decades, which has led to greater coastal flooding (Horton et al. 2014). Flooding and freshwater runoff events have become more frequent due to increases in extreme precipitation, which is expected to continue, particularly in the winter (Horton et al. 2014). Degradation of coastal habitats will prompt declines in fish and shellfish populations, particularly in enclosed bays and estuaries, which serve as important nursery and foraging habitats for fish and shellfish (Najjar et al. 2010). In New England, red crab (Chaceon quinquedens) may experience declines in growth due to acidification and scallop (Placopecten magellanicus) populations may also be vulnerable, though there is limited research on their vulnerability to acidification (NEFMC 2014). Shellfish in the Gulf of Maine will be particularly susceptible to ocean acidification due to cold waters and nutrient-rich freshwater runoff (Island Institute 2013).

Impacts on Commercial Fisheries

Commercial fishing is a cornerstone of the regional economy, particularly in New England. Northeast fish stocks have already been subject to declines, with observed decreases in total landings of major species over the last four decades (EAP 2009). Redistribution of traditionally fished commercially valuable stocks (e.g., cod, yellowtail flounder [Pleuronectes ferruginea]) will be one of the greatest effects felt by regional commercial fishermen and operators. Some species have already shifted, including red hake (Urophycis chuss), moving from the Mid-Atlantic Bight north to the Gulf of Maine (EAP 2009; Pinsky and Fogarty 2012), and Atlantic surfclam (Spisula solidissima), shifting northward and to deeper waters (McCay et al. 2011).

Commercial fishing operations have tracked distribution for both species (McCay et al. 2011; Pinsky and Fogarty 2012). In a historical analysis of spatial distribution of Northeast fish stocks, Nye et al. (2009) found statistically significant northward and mean-depth shifts for many commercially valuable stocks. For species such as silver hake (Merluccius bilinearis) that have a distinct northern and southern stock, northward shifts of the southern stock may lead to merging of two previously distinct stocks that were managed separately (Link et al. 2010). The potential for the merging of two previously distinct stocks highlights the need for managers to re-evaluate existing management policies (Nye et al. 2009; Link et al. 2010).

The New England cod (Gadus morhua) fishery is vulnerable to multiple stressors. For instance, the Gulf of Maine and Georges Bank cod stocks are likely to experience disruptions in spawning activity, egg development, and recruitment, and mismatches with prey availability (NEFMC 2014), though Gulf of Maine stocks will be less vulnerable due to smaller predicted increases in temperature (Fogarty et al. 2008). Given that the Gulf of Maine stock is low relative to historic levels and the Georges Bank stock is still considered overfished, these stocks are highly sensitive to climate stressors and on the verge of collapse (Pershing et al. 2015).

At the southern end of the Northeast region, there are also species with a variety of anticipated responses. In Chesapeake Bay, for instance, warmer-water species such as southern flounder (Paralichthys lethostigma) and tarpon (Megalops atlanticus) are likely to benefit from warming temperatures (Najjar et al. 2010). Atlantic croaker likewise responds favorably to warm conditions and may exhibit 60-100% increases in biomass by 2100 (Hare et al. 2010). Species at the upper end of their thermal tolerance such as black sea bass (Centropristis striata) may migrate northward or deeper and experience reduced production (Najjar et al. 2010).

New England red crab will be vulnerable to declines in growth and survival due to ocean acidification, though they are able to tolerate a wide thermal range and are unlikely to be vulnerable to temperature shifts (NEFMC 2014). American lobster (Homarus americanus) populations may also experience declines due to acidification (Island Institute 2013), though increasing temperatures and earlier shoreward migration may provide opportunities for an extended lobster fishing season (Mills et al. 2013). In the Mid-Atlantic, shellfish such as soft-shell clams (Mya arenaria) and blue crabs will be vulnerable to the compounding stressors of hypoxia, ocean acidification, and rising temperatures, and may experience decreased survival and reproductive success (Najjar et al. 2010).

Impacts on Recreational Fisheries

There is limited literature regarding the impacts of climate change on recreational fishing in the Greater Atlantic. Recreational fishing revenue, including trip-related expenses and fishing goods, totaled $4.6 billion from Maine to Virginia in 2011 (NOAA 2014). Declines in species targeted by recreational fishermen have the potential to have large cascading economic effects. Several of the species targeted by commercial fishermen, such as cod, flounder, and skates, are also targeted by recreational anglers, and are subject to various climate-driven stressors (NOAA 2014). Although declines in fish species may limit recreational fishing opportunities, traditional recreational species may be replaced by new species that migrate northward.

Impacts on Subsistence & Traditional Fisheries

There is limited information available regarding climate impacts on subsistence and traditional fisheries in the region; however, ocean acidification will likely be a primary impact of concern for shellfish fisheries. Tribal communities in New England depend on harvest of lobsters and shellfish, which may decline due to increasingly acidic ocean conditions (NAU 2014). In the Mid-Atlantic, tribal communities collect and use hard clam or Northern quahog (Mercenaria mercenaria), whelk, and conch shells to create wampum beads (MAROA 2015); these species will also be vulnerable to acidification. The Shinnecock, Pamunkey, and Seneca tribes in the Mid-Atlantic operate finfish and shellfish hatcheries, which are vulnerable to ocean acidification and sea level rise (MAROA 2015).

Impacts on Aquaculture

Shellfish aquaculture is a widespread multimillion-dollar industry (Lapointe 2013), which is rapidly growing in the Greater Atlantic region. Finfish aquaculture operations include facilities for salmon, halibut, and black sea bass (Lapointe 2013). Other popular species cultured in the region include Northern quahog, Atlantic oyster (Crassostrea virginica), blue mussel (Mytilus edulis), soft-shell clam or steamer (Mya arenaria), Atlantic salmon (Salmo salar), and nori seaweed (Porphyra spp.) and other macroalgae (Buttner et al. 2008). Potential changes in water quality and conditions due to rising sea temperature, increasing ocean acidification and hypoxia, and rising sea levels could cause declines in the production of farmed finfish and shellfish species. However, rising sea temperatures may actually benefit aquaculture in some cases; in Chesapeake Bay, for instance, decreased freezing of shoreline habitat could lead to the formation of new oyster reefs and open new areas for aquaculture facility development (Najjar et al. 2010).