Landscape Project Version 3.1 - State of New Jersey

24 | Landscape Project Version 3.1 | CONSERVING IMPERILED WILDLIFE OF NEW JERSEYFRESHWATER MUSSEL HABITATDEP maintains a Stream Network data layer that is a subset of the USGS 1:24,000 high-resolution National HydrographyDataset (NHD). In Version 3.1 of the Landscape Project, stream and water body centerlines from theNHD Streams 2002 data layer are used to represent freshwatermussel habitat.The Eastern Pondmussel (Threatened) can be found in the lowerhalf of the Delaware River and several of its tributaries.Water body centerline and stream centerline data are valuedexclusively by freshwater mussel species occurrence areaswhile other aquatic species habitats are represented withpolygons from the Species-Based Habitat layer. In order toform representative “patches” of habitat from the NHDStreams 2002 layer, centerlines were broken at the confluenceof two or more streams or the inflow/outflow of awater body.Stretches of stream intersected by a mussel SOA are valued as habitat. All valued streams are buffered by 0.75 kilometersupstream and downstream. e 0.75 kilometer distance is chosen as a conservative buffer estimate becausescientific literature based largely upon larval transport by host fishes, indicates that if there are two occurrenceswithin two kilometers of each other (assuming unsuitable habitat between), these occurrences should be consideredas part of the same local population (NatureServe 2011). In the cases where stream buffers of separate occurrences ofthe same species meet, either upstream or downstream, the stream segments between those occurrences are also valuedfor that species. In addition, in cases where dams are barriers the extent of stream valued was limited.The tidewaters of Pompeston Creek in Burlington Countyprovide ideal habitat for the Eastern Pondmussel.Stream centerlines are used to represent freshwater musselhabitat in Version 3.1 of the Landscape Project.