Data Management Plan

This data set contains sensitive biological resource data for marine, estuarine, and freshwater invertebrate species, as well as terrestrial insects in Chesapeake Bay and the Outer Coasts of Maryland and Virginia. Vector polygons in this data set represent invertebrate distribution and concentration areas. Vector points in this data set represent invertebrate occurrences. Species specific abundance, seasonality, status, life history, and source information are stored in relational data tables (described below) designed to be used in conjunction with this spatial data layer. This data set comprises a portion of the ESI data for Chesapeake Bay and the Outer Coasts of Maryland and Virginia. ESI data characterize the marine and coastal environments and wildlife by their sensitivity to spilled oil. The ESI data include information for three main components: shoreline habitats, sensitive biological resources, and human-use resources.

This reflects the extent of all land and water features included in the overall Chesapeake Bay and Outer Coasts of Maryland and Virginia 2016 ESI study region. The bounding box for this particular feature class may vary depending on occurrences identified and mapped.

Lineage Statement:
This atlas supersedes two separate first edition atlases, Virginia (2005, #25) and Maryland (2007, #47).

Process Steps:

• 2016-09-01 00:00:00 - INVERTEBRATE Polygons: Marine and estuarine distributions of brown shrimp, white shrimp, mantis shrimp, squid species and blue crab were mapped using fishery-independent data from the NEAMAP, ChesMMAP, VIMS Juvenile Fish and Blue Crab Trawl surveys and expert opinion from MD DNR and VIMS. General distributions of oysters and other shellfish species in Virginia were mapped using data from shellfish lease areas and expert knowledge by resource managers at VA MRC and from the Habitat Requirements for Chesapeake Bay Living Resources. Oyster reefs mapped in the coastal bays of Virginia came from digital data provided by VIMS from the Population Assessment of Eastern Oysters (Crassostrea virginica) in the Seaside Coastal Bays. Points were buffered by 25 meters and merged together based on input from VIMS scientists. In Maryland, shellfish species data comprise a combination of survey data, reports and expert knowledge provided by MD DNR shellfish researchers. These include Maryland's DNR Oyster Dredge Survey, Coastal Hard Clam Survey and Assessment of Chesapeake Bay Commercial softshell clams, Mya arenaria and Tagelus plebeius. Oyster reefs mapped in the ESI are not necessarily the only reefs in coastal areas, but represent current and potential oyster habitat in the bays. Additional invertebrate species were mapped into the coastal bays of Virginia and Maryland and in marine waters out to 12 NM based on survey data from NEAMAP and expert knowledge from resource managers and scientists at MD DNR, VA MRC and VIMS. All spatial and attribute data in this ESI were finalized through systematic review by scientists and resource experts from MD DNR, VA MRC and VIMS. Horseshoe crab spawning beaches came from three different sources. In the Coastal Bays of Maryland, spawning beaches represent expert knowledge provided by Steve Doctor. Spawning beaches in Tom's Cove were mapped from the Tom's Cove, Virginia Horseshoe Crab Tag Recovery Study Interim Report. Lastly, a number of small spawning sites within Chesapeake Bay were mapped using public sighting data provided by MD DNR. Horseshoe crabs utilize whatever appropriate habitat that is available inside Chesapeake Bay for spawning, and these areas can shift over time. Freshwater mussels represent VDGIF's Freshwater Mussel database, MD DNR's Ecologically Significant Areas database, and the Maryland Biological Stream Survey data. Species observations mapped from the VDGIF database were restricted to the dates 1995-2013, and only include records that fell within 1000m of ESI water bodies that are continuous to the ocean. Species mapped in Maryland have similar importance, but also include two endangered species: the dwarf wedgemussel (FE, MD SE) and the triangle floater (MD SE). Species mapped from MD DNR's Ecologically Significant Areas database are restricted based on date of last survey and include the years 1996 to 2016. A number of insects of conservation concern were mapped in Maryland using MD DNR's Ecologically Significant Areas database. Records were selected based upon date of last survey, and include data from 1996 to 2016. Northeastern beach tiger beetle (FT, MD SE, VA ST) occurrences in Virginia were mapped from a USFWS hard copy map. Northeastern beach tiger beetles were mapped in the study area according to expert knowledge.
• 2016-09-01 00:00:00 - INVERTEBRATE Points: Mussels mapped in Virginia represent rare species that are of conservation concern and are of significant ecological importance. Species observations mapped from the VDGIF database were restricted to the dates 1995-2013. Data mapped in Maryland includes only one species of fresh water mussel, the Eastern elliptio, and date ranges for this data spans 1995-2014. Both data sets were mapped only with a 1000 meter buffer extending from the ESI water polygon layer, in an effort to restrict the occurrences to those likely to be impacted during a spill response scenario.
• 2016-09-01 00:00:00 - Data from the above sources were compiled by the project biologist to create the INVERTEBRATE POLYS and POINTS data layers. Three general approaches are used for compiling the data layer: 1) information gathered during initial interviews and from hardcopy sources are compiled onto U.S. Geological Survey 1:24,000 topographic quadrangles and digitized; 2) hardcopy maps are digitized at their source scale; 3) digital data layers are evaluated and used "as is" or integrated with the hardcopy data sources. See the Lineage section for additional information. Once the ESI, biology, and human-use data are compiled into the standard ESI digital data format, a second set of interviews with participating resource experts are conducted to review the compiled data. If necessary, edits to the INVERTEBRATE POLYS and POINTS data layers were made based on the recommendations of the resource experts, and final hardcopy maps and digital data are created.

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).