9. Mid-Atlantic Bight Region Acidification Research Christopher Kinkade¹, Shannon L
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9. Mid-Atlantic Bight Region Acidification Research Christopher Kinkade¹, Shannon L. Meseck², R. vertically resolved carbonate dynamics Christopher Chambers³, Dwight K. Gledhill4, Kim- with an increased emphasis at reactive berly J. W. Hyde5, Chris Melrose5, Beth Phelan³, interfaces (e.g., sediment boundary, Matthew E. Poach², Elizabeth Turner6 land-ocean, etc.) in context with other environmental change; ¹NOAA/NOS, Office for Coastal Management, Woods Hole, MA • Determine how OA in concert with other ²NOAA/NMFS, Northeast Fisheries Science Center, Milford stressors impact ecologically and/or Laboratory, Milford, CT economically important marine species, ³NOAA/NMFS, James J. Howard Marine Laboratory, Highlands, with a focus on understanding impacts to NJ aquaculture stocks; 4NOAA/OAR, Ocean Acidification Program, Silver Spring, MD • Evaluate costs and benefits of mitigation 5NOAA/NMFS, Northeast Fisheries Science Center, Narragansett and adaptation strategies for communities, Laboratory, Narragansett, RI ecosystems and economies; and 6NOAA/NOS, National Centers for Coastal Ocean Science, Durham, NH • Promote integration of OA understanding into regional planning and management. Abstract Acidification in the Mid-Atlantic Bight The Mid-Atlantic Bight Region includes the east- Region ern United States continental shelf area extending Presented in this chapter are the mid-term priorities from Cape Hatteras, NC to Cape Cod, MA. Ocean and objectives of NOAA’s OA research, modeling, acidification (OA) in the region is modified by ocean and monitoring interests specific to the waters of circulation patterns, particularly influenced by the the Middle Atlantic Bight (MAB; Figure 9.1). The Labrador Sea water that forms the cold pool, nat- MAB extends from Cape Hatteras, NC, to the south- ural seasonal and decadal variability, and eutrophi- ern coast of Cape Cod, MA, and is part of the North- cation. The Mid-Atlantic Bight is home to important east U.S. Continental Shelf Large Marine Ecosystem commercial shellfisheries and finfish, which have (LME). For information on the northern region of the shown some sensitivity to OA. NOAA’s Mid-Atlantic Northeast LME, please refer to Chapter 10, New En- Bight Region research goals are to: gland Region Acidification Research Plan. • Improve OA forecasts across daily to The MAB is characterized by a large continental decadal timescales informed through a shelf, multiple shelf break canyons, five geographi- modified regional observing system that cally distint estuarine ecosystems (Chesapeake Bay, better quantifies the primary drivers of NOAA Ocean, Coastal, and Great Lakes Acidification Research Plan | 83 Figure 9.1. The Mid-Atlantic Bight region with depth, from Southern Massachusetts to Cape Hatteras, NC. Water from the Gulf Stream comes in from the south, while the Shelf Break Jet brings water from the North. Warm and cold core rings can be found along the Gulf Stream. Credit: NOAA Delaware Bay, Long Island Sound, the coastal bays cies in this region (Powell et al., 2020; Weinberg, in Maryland and Virginia, and the Albemarle-Pamli- 2005). The MAB is also characterized by regions of co Estuarine System), and barrier islands that en- upwelling along the shelf break (Benthuysen et al., close shallow coastal bays (e.g., Great South Bay 2015; Brooke et al., 2017). Along the coast, south- (NY), Barnegat Bay-Little Egg Harbor Estuary (NJ), west winds associated with the Bermuda High and Assawoman Bay (DE), and Chincoteague Bay (MD). Ekman forcing can also result in upwelling regions Polar water from the Labrador Current and warm- (Glenn et al., 2004). Upwelling areas in the MAB are er water from the Gulf Stream meet in this region, characterized with enhanced primary productivity, resulting in dynamic distributions of temperature, intense fishing activity, and low dissolved oxygen salinity, and density over vertical and lateral scales. concentrations. During the fall, storms (i.e., hurricanes, Nor’easters) bring strong winds, which lead to a well-mixed wa- Key physical and biogeochemical drivers, such as ter column (Lentz, 2003; Rasmussen et al., 2005). seasonal changes in net-community production, However, during the late spring/early summer temperature, salinity, physical mixing, and nutrient strong surface heating and weakening winds lead loading, in addition to air-sea gas exchange influ- to the development of a thermocline about 20 me- ence acidification in the MAB region. For example, ters deep, spread across the entire shelf, creating a Gulf Stream waters along the southern portion of the MAB have elevated aragonite saturation (Ω ). continuous mid-shelf “cold pool” (Figure 9.2; Gold- arag smith et al., 2019; Wang, 2016). The “cold pool” has In contrast the less buffered northern region of the been linked to the distribution and recruitment of MAB is influenced by colder southward coastal cur- commercial and recreational fin and shellfish spe- rents fed by Labrador Sea (Wanninkhof et al., 2015) and Gulf of Maine (Wang et al., 2013) water result- NOAA Ocean, Coastal, and Great Lakes Acidification Research Plan | 84 Figure 9.2. Bottom temperatures for part of the Mid-Atlantic region, showing the Cold Pool. Courtesy of: MARACOOS/Rutgers University ing in comparatively lower Ωarag. Closer to the coast, the Northeast (NE) region, marine aquaculture is ex- biological activity and eutrophication can affect panding in every state with the potential of offshore temporal and spatial variability in carbonate param- aquaculture throughout the coastal zone, highlight- eters (Cai et al., 2011; Wanninkhof et al., 2015; Xu ing the importance of characterizing the drivers of et al., 2017). Because the MAB supports a diverse OA in the MAB. With 5 major estuaries and many assemblage of commercially and recreationally coastal barrier island bays, eutrophication may important finfish (bony and cartilaginous) species contribute substantially to OA in this region (Gold- (Gates, 2009; Sherman et al., 1996), and critical smith et al., 2019; Kennish et al., 2007, 2016; Saba shellfish fishing grounds, hatcheries, aquaculture et al., 2019) affecting growth, survival, and calcifi- beds, and oyster restoration areas, it may prove to cation of several larval shellfish species (Clements be an area uniquely vulnerable economically to both & Chopin, 2017; Clements & Hunt, 2014; Gobler & ocean and coastal acidification. Talmage, 2014; Hattenrath‐Lehmann et al., 2015), finfish species (Chambers et al., 2014; Perry et al., The MAB has a diverse assemblage of flora and 2015), and crustaceans (Giltz & Taylor, 2017; Glan- fauna including commercially and recreationally im- don et al., 2018; Glandon & Miller, 2016). Conse- portant shellfish and finfish, deep water hard corals, quently, many coastal communities in the MAB have soft corals and sea fans, as well as shellfish hatch- a medium-high to high vulnerability risk to OA, with eries, aquaculture leases, and oyster restoration ar- anticipated effects by 2071 (Ekstrom et al., 2015). eas (Dubik et al., 2019; McManus et al., 2018; Mun- Understanding the physical and biogeochemical roe et al., 2016; Narváez et al., 2015; Powell et al., drivers of OA, organism responses to these drivers, 2020; Schweitzer & Stevens, 2019; Waldbusser et and the socioeconomic effects on the fishing and al., 2013). Fisheries in the MAB region totaled $800 aquaculture industries, recreational fisheries, and million in 2016 with sea scallops, blue crab, and the tourism will help determine if mitigation strategies eastern oyster accounting for 56% of the total reve- need to be implemented in some communities to nues (NEFSC, 2018; NOAA Fisheries, 2019b). As in reduce the effects of OA. NOAA Ocean, Coastal, and Great Lakes Acidification Research Plan | 85 Environmental Change in the Mid- demands simultaneous observations of physical, Atlantic Bight Region biological, and chemical parameters within the re- gion to better inform OA forecasts and projections. Surveys of surface carbonate chemistry in the MAB conducted by NOAA and other research institutions Improved biogeochemical models that describe have shown large natural variability on decadal OA conditions and interactions with environmental timescales (Boehme et al., 1998; Wang et al., 2017, conditions are necessary to develop decision sup- 2013). Regional satellite-derived surface pCO2 algo- port tools. These models should focus on creating rithms depict strong seasonal variability with lower accurate short- and long-term projections that aid efforts to better evaluate species sensitivity and po- pCO2 values in winter and spring and higher pCO2 values during the summer and fall primarily driven tential Blue Economy vulnerability. Specifically, us- by seasonal temperature dynamics. Repeated ship- ing down-scaled Global Circulation Models (GCMs) board campaigns have shown relatively low pH, to hindcast historical changes in carbonate chemis- try would help assess the evolution of acidification Ωarag, and buffering capacity of waters of the north- eastern U.S. shelves, which indicates elevated risk through time beyond the limited domain of the ob- to continued acidification compared to southern serving system. Further refinement of down-scaled counterparts (Figure 9.3; Wang et al., 2013). Limit- GCMs may then be used to project future long-term ed MAB bottom water CO2SYS surveys have shown changes with respect to OA. Because tempera- enhanced seasonal stratification relative to surface ture, oxygen levels, and eutrophication change on conditions, as respiratory