Data Management Plan

This data set contains sensitive biological resource data for terrestrial, marine, and estuarine invertebrate species in Delaware Bay and nearby areas of Delaware, New Jersey, and Pennsylvania. Vector polygons in this data set represent invertebrate distribution and concentration areas. 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 Delaware/New Jersey/Pennsylvania. 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 Delaware Bay (Delaware, New Jersey, Pennsylvania) 2014 ESI study region. The bounding box for this particular feature class may vary depending on occurrences identified and mapped.

Lineage Statement:
For each species, the mapping extent was dependent upon information availability and location of mapped coastal habitats and shorelines. Invertebrates depicted in this atlas include select terrestrial, marine, and estuarine species of commercial, ecological, and/or conservation interest.

Process Steps:

• 2014-03-01 00:00:00 - Horseshoe crab, blue crab, eastern oyster, knobbed and channeled whelk, Atlantic surfclam, and northern quahog support highly valuable commercial shellfisheries in the Delaware Bay region. Horseshoe crab spawning beaches were mapped using data from the 2013 report "Horseshoe crab spawning in Delaware Bay: 1999-2012" to the Atlantic States Marine Fisheries Commission's Horseshoe Crab Technical Committee. In Indian River Bay and Rehoboth Bay, spawning beaches were mapped using data from the Center for Inland Bays. Horseshoe crab distributions within Delaware Bay were mapped based upon catches in fishery independent trawl sampling data from Delaware Department of Natural Resources and Environmental Control (DNREC) and New Jersey Department of Environmental Protection Bureau of Shellfisheries (NJDEP BS). Distributions in the Atlantic Ocean were based mainly on published literature and expert knowledge. Data on eastern oyster distributions was provided by DNREC and NJDEP BS/Rutgers University. DNREC provided polygonal and point spatial data on oyster reef locations on the western side of Delaware Bay and its tributaries and NJDEP BS and Rutgers provided polygonal data for the larger oyster reef complexes on the New Jersey side of Delaware Bay. The timing of life history stages and seasonalities for all eastern oyster records were based on Estuarine Living Marine Resources (ELMR) data and expert review. Rare and endangered species of insects and other invertebrates from Delaware were mapped in part by using element occurrence data provided by DNREC. Species names were obscured to protect sensitive resources. Polygons in element occurrence records with a diameter greater than 100 meters (m) were mapped as is, and all other polygons were mapped after applying a polygonal buffer and a randomized geographic shift. Blue crab distributions were mapped in Delaware Bay based on expert knowledge from DNREC staff, and data from the fishery independent sampling surveys conducted by DNREC and NJDEP BS. Seasonality and life history stages were drafted from published literature and refined during reviews with DNREC staff. In the Inland Bays of Delaware and New Jersey, blue crab distributions, concentrations, and seasonalities were based upon mid-Atlantic ELMR data. Freshwater mussels were mapped in the Delaware River and small water bodies in Delaware and New Jersey based on data provided by DNREC, NJDEP Endangered and Nongame Species Program (ENSP), and Partnership for the Delaware Estuary (PDE). In the case of DNREC and PDE data, species names were masked to protect rare mussels. DNREC element occurrence polygons were buffered and randomly shifted when they were less than 100 m in diameter. Northern quahog was mapped in New Jersey based upon NJDEP BS hard copy documents. Additional records for northern quahog were mapped in New Jersey and Delaware from the mid-Atlantic ELMR report, in which data on occurrence and abundance of a species is generalized to much larger areas. Data on Atlantic surfclam distributions in NJ coastal waters was provided by NJDEP BS as a report on stock inventories. Report data was used to create three geographic regions with separate concentrations along the NJ coast. Mid-Atlantic ELMR data was used to fill in information about species or regions that are not directly sampled by DNREC or NJDEP BS staff. Presence/absence, concentrations, and life history stages were all incorporated as is for select geographies. These geographies include Barnegat Bay, inland bays of NJ, Delaware Bay, and the inland bays of DE. Species mapped from mid-Atlantic ELMR data include American lobster, blue crab, blue mussel, northern quahog, and softshell clam.
• 2014-03-01 00:00:00 - The above digital and/or hardcopy sources were compiled by the project biologist to create the INVERTEBRATES data layer. Depending on the type of source data, 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 1:45,000 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 on the type of source data for this data layer. 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 INVERTEBRATES data layer are 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).