Data Management Plan

This data set contains sensitive biological resource data for benthic species in Massachusetts and Rhode Island. Vector polygons in this data set represent a few different species of submerged aquatic vegetation (SAV) and macroalgae. 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 BENTHICPT (Benthic Points) data layer for additional benthic information.

Process Steps:

• 2016-01-01 00:00:00 - Developing ESI data for Submerged Aquatic Vegetation (SAV). The most common SAV species in Massachusetts and Rhode Island is eelgrass (Zostera marina), but widgeon grass (Ruppia maritima) can be found as well in areas of less salinity. All SAV were assigned the mapping qualifier of “High Ecological Value”. Polygons depicting SAV in Rhode Island are primarily based on the 2012 dataset developed by the Rhode Island Eelgrass Mapping Task Force that utilized aerial survey and ground truthing as production methods. These areas of SAV were mapped with a concentration value of “Present”. Two SAV datasets produced by the URI Environmental Data Center in 2006 and 2009 were also used where they did not overlap the 2012 data, and these polygons were mapped with a concentration value of “Potential” based on local resource expert input. Jim Turenne, USDA-NRCS, provided input for additional widgeon grass coverage in coastal ponds in Little Compton and Sachem Pond on Block Island. Polygons depicting SAV in Massachusetts are based on datasets developed by the MassDEP Wetlands Conservancy Program Eelgrass Mapping Project in 2010, 2012, and 2013, all three layers of which together cover the entire Massachusetts coastline. MassDEP has been surveying since 1995 and relies on remote sensing of aerial imagery supplemented by underwater video data to acquire SAV extents. Additional eelgrass coverage was provided by Kathryn Ford, MDMF, for the Town of Sandwich, and by Todd Callaghan, Mass CZM for Boston Harbor and Salem Sound. All of these areas of SAV were mapped with a concentration value of either “Present”, “Patchy”, or “Dense”. Mass CZM produced a dataset for the 2015 Massachusetts Ocean Management Plan that augmented the MassDEP data by adding eelgrass patches from state and federal divers, and also historic and buffer data to include areas that might not have eelgrass currently but should be protected. Where these latter data did not overlap existing eelgrass polygons, they were mapped with a concentration of “Potential”. Two rare freshwater plants species, cutleaf watermilfoil (Myriophyllum pinnatum)(state threatened) and hornleaf riverweed (Podostemum ceratophyllum)(state species of concern) were also mapped as SAV in Rhode Island with a mapping qualifier of “Vulnerable Occurrence” and a concentration of “Present” using the 2016 RI DEM Natural Heritage Areas data. MADFW NHESP provided a single dataset for ten coastal and estuarine plant species that depend on the dynamic interface of land and water that changes on the coast with regularity. The areas of these data located in water were mapped as “Rare aquatic/wetland plant” (SAV) with the mapping qualifier “High Ecological Value” and a concentration of “Present”. (Citation: MASSDEP 2013 EELGRASS MAPPING)
• 2016-01-01 00:00:00 - Developing ESI data for Macroalgae. Macroalgae mapped for Rhode Island includes both red (Rhodophyta) and green (Chlorophyta). Both species have a year-round presence, but green algae have a strong seasonal component and are only present in large abundances in the summer and fall (Green and Deacutis, personal communication). Distribution polygons in Narragansett Bay based on data from summer and fall aerial surveys conducted by RI DFW between 2007 and 2012, and along coastal ponds and rocky shores by expert input from Lindsay Green and Carol Thornber, URI. Only high density accumulations were mapped with a concentration value of either 41-70% or 71-100% of total cover. Macroalgae depicted in Massachusetts consist of aquatic vegetation beds mapped as points using three data layers developed by Mass CZM for the 2015 Massachusetts Ocean Management Plan: Attached Mussel Beds, Canopy-forming Algal Beds (Kelps), and Soft Corals. These datasets indicate locations where benthic biota was observed in analyzed seafloor photographs from 2013, and the biological information was classified according to a modified version of the Coastal and Marine Ecological Classification Standard (CMECS), Version 4.0, Benthic Biotic Component (Federal Geographic Data Committee, January 2012). The biotic subclass of macroalgae were extracted from these data and mapped with a concentration value of “Medium” based on density of cover. All digital data received from MA and RI for the Benthic Layer were edited as necessary to match NOAA ESI Shoreline layer included in this atlas. (Citation: NARRAGANSETT BAY MACROALGAE FALL AND SUMMER HIGH DENSITY 2007-12)

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).