Data Management Plan (Deprecated)

This data set contains sensitive biological resource data for marine mammals in Massachusetts and Rhode Island. Vector polygons in this data set represent known dolphin, whale, and pineped concentration areas and haul-out sites. Species-specific abundance, seasonality, status, life history, and source information are stored in associated data tables (described below) designed to be used in conjunction with this spatial data layer. This data set is a portion of the ESI data for Massachusetts and Rhode Island. As a whole, the ESI data characterize the marine and coastal environments and wildlife by their sensitivity to spilled oil, and include information for three main components: shoreline habitats, sensitive biological resources, and human-use resources. See also the M_MAMPT (Marine Mammal Point) data layer for additional seal information.

Process Steps:

• 2016-01-01 00:00:00 - Step 1. Developing ESI data for cetacean species. General distribution for whales, dolphins, and porpoises was mapped as large polygons based on NROC’s 2016 habitat-based density models, Atlantic Marine Assessment Program for Protected Species (AMAPPS) line transect survey data (2013-2014), and the 2010 report Marine Mammals and Sea Turtles of Narragansett Bay, Block Island Sound, Rhode Island Sound, and Nearby Waters: Analysis of Existing Data for the Rhode Island Ocean Special Area Management Plan (Kenney and Vigness-Raposa). Species distribution maps in the Rhode Island Ocean SAMP analysis were created using modeled seasonal relative abundance patterns generated from seasonal sightings per unit effort (SPUE) values, as well as aggregated sighting, stranding, and bycatch records. With the exception of Cape Cod Bay, survey data within bays and sounds is limited and often terminates at COLREGS Demarcation Lines. These lines and 20’ depth contours were used to define the boundary between inshore and offshore marine mammal distribution polygons in this atlas. Input from local resource experts at New England Aquarium, NEFSC, GARFO, and University of Rhode Island Coastal Institute informed inshore as well as offshore species presence and concentrations. Cetaceans mapped in Narragansett Bay are restricted to the harbor porpoise, a few species of dolphin, and pilot whales. A higher biodiversity of species can be found in Buzzards Bay, Nantucket Sound, and Cape Cod Bay, and includes fin, humpback, and North Atlantic right whales. All cetaceans are indicated as having a year-round presence, though seasonal concentrations vary among species and by location. Many species peak in offshore waters during the spring and summer and are rarest in winter, whereas Cape Cod Bay exhibits increased species presence during the colder months of the year due in part to mass stranding. A number of species including beluga and Bryde’s whales visit the atlas area but are not recorded with any consistency and are mostly anecdotal records. These species typically occur farther offshore and were not mapped due to their rarity in the AOI. Concentration areas for fin, humpback, and North Atlantic right whales were included in Massachusetts using 2015 Massachusetts Ocean Management Plan Core Habitat vector digital data (Mass CZM). This dataset is based on sightings from 1998-2014. These state and federally endangered species are considered a special, sensitive, or unique (SSU) resource and regularly use Massachusetts waters for feeding. Cape Cod Bay is particularly rich in nutrients and is a significant foraging area for other marine mammals as well.
• 2016-01-01 00:00:00 - Step 2. Developing ESI data for pinniped species. Harbor seals are the most common pinniped species in New England coastal waters and have increased significantly in abundance over the last few decades. They are present year-round off the coast of Massachusetts and Rhode Island, but are most common as a winter resident south of Cape Cod as they migrate from the Gulf of Maine in September to warmer waters in pursuit of abundant food resources (Raposa and Dapp, 2009). Harbor seal haulouts are most active October through May and are concentrated along the Cape and Islands, Block Island, and Narragansett Bay. Gray seals are present year-round as well and can regularly be seen hauling out with harbor seals at Monomoy Island, Chatham Harbor, Jeremy Point in Wellfeet, and Muskeget Island and Shoals off Nantucket. Most gray seals in Rhode Island are recently weaned pups in the spring and are spotted only occasionally with harbor seals, such as at the north end of Block Island (Kenney, personal communication). Breeding for gray seals occurs during the winter months (December through February) and has been noted at haulouts on Monomoy, Muskeget, and Nomans Islands. Harp and hooded seals are present in Massachusetts and Rhode Island waters as well November through May, but do not haul out regularly like harbors and grays. Known occurrences are either strandings or fishery bycatch records (Kenney, personal communication). Harbor and gray seal haulout locations, seasonality, and breeding activity in Massachusetts were provided by Beth Josephson, NEFSC. Harbor seal haulouts in Rhode Island were mapped according the 2009 report A Protocol for Long-term Monitoring of Harbor seals (Phoca Vitulina Concolor) in Narragansett Bay, Rhode Island (Raposa and Dapp) that is based on seal counts conducted in 2007-2008. This information was supplemented by vector point data from Cheryl Schroeder, Save the Bay (2005), and Wenley Ferguson, Save the Bay, who provided data for two sporadic haulout sites along the Sakonnet River. All digital data obtained from Massachusetts and Rhode Island for the Marine Mammals Layer were edited as necessary to match NOAA ESI Shoreline layer included in this atlas.

Data can be accessed by downloading the zipped ArcGIS geodatabase from the Download URL (see Distribution Information). Questions can be directed to the ESI Program Manager (Point Of Contact).