title: Understanding water column and streambed thermal refugia for endangered mussels in the Delaware River.
abstract: Groundwater discharge locations along the upper Delaware River, both discrete bank seeps and diffuse streambed upwelling, may create thermal niche environments that benefit the endangered dwarf wedgemussel (Alasmidonta heterodon). We seek to identify whether discrete or diffuse groundwater inflow is the dominant control on refugia. Numerous springs and seeps were identified at all locations where dwarf wedgemussels still can be found. Infrared imagery and custom high spatial resolution fiber-optic distributed temperature sensors reveal complex thermal dynamics at one of the seeps with a relatively stable, cold groundwater plume extending along the streambed/water-column interface during midsummer. This plume, primarily fed by a discrete bank seep, was shown through analytical and numerical heat-transport modeling to dominate temperature dynamics in the region of potential habitation by the adult dwarf wedgemussel.
authors.affiliation: Office of Groundwater, Branch of Geophysics, U.S. Geological Survey , 11 Sherman Place, Unit 5015, Storrs, Connecticut 06269, United States.
authors.forename: Martin A
authors.initials: MA
authors.lastname: Briggs
authors.forename: Emily B
authors.initials: EB
authors.lastname: Voytek
authors.forename: Frederick D
authors.initials: FD
authors.lastname: Day-Lewis
authors.forename: Donald O
authors.initials: DO
authors.lastname: Rosenberry
authors.forename: John W
authors.initials: JW
authors.lastname: Lane
mesh_terms: D000818:Animals; D049872:Bivalvia / Q000502:physiology*; D003691:Delaware; D017753:Ecosystem; D056727:Endangered Species; D005843:Geography; D060587:Groundwater; D010414:Pennsylvania; D045483:Rivers; D013696:Temperature; D013997:Time Factors; D014867:Water
chemical_list: D014867:Water