Habitats

Coastal habitats on Martha’s Vineyard, Gosnold (Elizabeth Islands), and Nantucket provide extraordinary ecological and economic value, with 68,600 acres that are home to many rare and threatened species. In the winter, snowy owls, mergansers, and bufflehead ducks frequent Norton Point. In the warmer months, Cape Poge Bay attracts striped bass and bluefish, and nests of piping plovers, least terns, and oystercatchers. Martha’s Vineyard has one of the only nesting colonies of black skimmers in Massachusetts — one of the latest species to expand their range north with the warmer climate.

Photo credit: Above Summit

Photo credit: Above Summit

We may worry about the future of our homes amid rising seas, but climate change poses no less a threat to natural habitats. Its impacts go beyond intensified storms, erosion, and sea level rise to include the ocean’s warming temperatures and acidification. These effects — compounded by pollution, disease, contamination, tidal restrictions, nutrient loading, and sedimentation — threaten to significantly degrade and destroy estuaries, including mudflats, eelgrass, shorebird nesting sites, and shellfish beds. 

WHAT THE DATA SHOWS 

  • THE FUTURE OF SHELLFISHING IS IN JEOPARDY. On Nantucket, the scallop harvest is down to 8,000 bushels this year, from about 100,000 bushels in the 1980s [CIT. 13]. Wild oysters also appear to be on the decline, though there has been growth in aquaculture and oyster farming [CIT. 11]. 

  • TOXIC ALGAE BLOOMS ARE OCCURRING WITH INCREASING FREQUENCY, including at the head of Nantucket Harbor [CIT. 11]. Algae can smother eelgrass, which impacts scallops. 

  • EELGRASS IS UNDER STRESS FROM HUMAN IMPACTS (scallop draggers, prop wash, and mooring scour, for example), warming waters, and decreased light due to sea level rise. The density of eelgrass meadows in Nantucket Harbor declined to 17% in 2020 from 36% in 2016 [CIT. 11], and restored eelgrass in Edgartown Great Pond continues to suffer from sedimentation. Eelgrass is critical, providing nursery habitat for commercially important shellfish (especially bay scallops) and fisheries. It also stabilizes sediments, removes pollutants, and sequesters carbon. 

  • HABITATS AND NESTING AREAS for migrating shorebirds and at-risk and protected species such as the roseate tern and American oystercatcher are likely to decline as nesting locations experience washover events, and some beaches narrow and grow steeper. 

  • WATER QUALITY is a major concern for island harbors and estuaries, though long-term monitoring is showing lower nitrogen levels in Nantucket Harbor, perhaps due to a recent fertilizer application by-law. 

  • SALT MARSHES can migrate in response to sea level rise, except where development or abrupt changes in elevation prevent this natural process, resulting in marsh loss. Also, as barrier beaches erode, the protection they provide to fringing salt marshes behind them will be lost. 

LOOKING AHEAD

Effective adaptation requires immediately developing and evaluating best practices and introducing innovative, at-scale solutions for the Vineyard and Nantucket. What is urgently needed now is active and collaborative work on a broad, Islands-wide strategy that discovers ways to provide habitat while sustaining its important functions. 

Based on the latest data, we propose strategically piloting scalable strategies and finding ways to strike a more sustainable balance between human recreation and shore-based activities (e.g. development, stormwater runoff, and fertilizers) and habitat conservation and restoration. 

CONSIDER 

ENACTING HABITAT-FRIENDLY REGULATIONS Where possible, applying conservation moorings or off-shore buoys that don’t drag along the seafloor or no-anchoring zones (as Tisbury did in Drew’s Cove) can help preserve eelgrass. Other remedies include addressing nutrient and septic system issues, regulating fertilizer use, and requiring green infrastructure for new development. 

COMMITTING TO NATURE-BASED SOLUTIONS Oysters cultivated at the Nantucket hatchery are growing at Shimmo Creek on a reef made from 100,000 pounds of recycled oyster and quahog shells. Martha’s Vineyard Shellfish Group is also spearheading shell recycling from homes and restaurants for oyster habitat and eelgrass restoration [CIT. 12]. Techniques such as snow-fencing and grass planting can help to stabilize eroding dunes, and restore salt marsh shorelines. 

MOVING OFFSHORE Coastal communities are increasingly using offshore reefs and reef-mimicking structures to provide habitat and reduce wave energy impacts on natural landscapes and harbors. Off the coast of Martha’s Vineyard, Cottage City Oysters established a 3D farm to produce eco-friendly oysters, clams, and seaweed. The state Division of Marine Fisheries also created an artificial reef program to provide additional fish habitat. 

GROWING BLUE ECONOMIES As threats to traditional industries grow, science and technology can help expand sustainable ocean-facing businesses. Low-cost aquaculture projects reduce reliance on fisheries and increase the diversity of food sources. For instance, Mook Sea Farm in Maine developed technology to grow microalgae for oyster larvae, among other innovations. 

LOBBY FOR TARGETED FUNDING Identifying coastal habitats as natural infrastructure would allow islands to rebuild natural spaces after storms, as they do with built infrastructure. FEMA also offers insurance incentives for the preservation of open space. These should be expanded to cover natural coastal defenses that provide values beyond protecting development and infrastructure. 

MANAGING PUBLIC ACCESS AND BEACH RESILIENCY The Trustees provides areas for walking and over-sand-vehicles, but limit access in areas to protect dune vegetation, intertidal shorelines, and allow natural dunes to rebuild — critical for beach resiliency. 

PRESERVE HABITAT MIGRATION CORRIDORS Conservation organizations island-wide can work together to make sure that corridors have ample space across diverse elevations and habitat types. 

SEEK OPPORTUNITIES What damages habitat for one species may create the right conditions for another. We don’t always need to resist change; sometimes, we can be ecological opportunists and use our collective efforts to make the most of it.