Environmental Drivers of Adult Atlantic Sturgeon Movement and Residency in the Delaware Bay

Abstract

Animals utilize various habitats throughout their life to optimize growth, fitness, and survival. Identifying environmental conditions and locations where animals exhibit different movement behaviors can be used to infer the relative importance of habitat types. In the case of threatened and endangered species, such as the Atlantic Sturgeon Acipenser oxyrinchus oxyrinchus, critical habitat designations are a tool used to promote conservation and recovery. We utilized an extensive passive acoustic telemetry array, observed atmospheric conditions and river flow, modeled seawater conditions, and used generalized additive mixed modeling to determine environmental predictors of Atlantic Sturgeon movement and residency in the Delaware Bay on the U.S. East Coast. Our results suggested that shallower waters, warmer bottom temperatures, and areas toward the eastern portion of the Delaware Bay were predictive of residency, while movement was predicted by increased depth, cooler bottom temperatures, and areas toward the western portion of the bay. Our findings add to a growing body of evidence highlighting habitats at the Delaware Bay mouth, where Atlantic Sturgeon occur at heightened concentrations from late spring through fall. The Delaware River estuary once supported the largest population of Atlantic Sturgeon in North America, but that population is now critically imperiled (or endangered). Atlantic Sturgeon spend the vast majority of their life in marine, polyhaline waters, and without enhanced protection for these habitats, their recovery may never be realized.

Endangered Atlantic Sturgeon in the New York Wind Energy Area: implications of future development in an offshore wind energy site

“…High incidences of Atlantic Sturgeon during the winter were observed in both years, with a marked increase in unique counts and total detections in November and December. The absence of Atlantic Sturgeon in the NY WEA during the summer months, particularly from June through September, suggests a putative shift to nearshore habitat and corresponds with periods of known-residence in shallow, coastal waters that are associated with juvenile and sub-adult aggregations as well as adult spawning migrations 29,55,63–65 .…”

“…Periods of residency and movement were calculated using the behavioral event qualifier in the R package “V-Track” 53–55 . A residence event was defined as a minimum of two successive detections of an individual at a single transceiver station over a minimum period of two hrs.…”

A satellite‐based mobile warning system to reduce interactions with an endangered species

“…After MODIS and VIIRS data were gap-filled, they were used as inputs for the projection of ASOM (Breece et al 2018) over the entire study area for each day of 2013, the only full year with overlapping coverage from MODIS, VIIRS, and Atlantic Sturgeon telemetry data. Additionally, one, two, and three-day probability forecasts, as well as daily climatologies based on the DINEOF gapfilled data as inputs to the ASOM, were made every day for each platform.…”

Comparative migration ecology of striped bass and Atlantic sturgeon in the US Southern mid-Atlantic bight flyway

“…Residency was calculated using daily incidence data and the V-Track package in R ( [67]; c/o Franklin Ecolab, The University of Queensland, St Lucia, Qld, Australia). The RunResidenceExtraction function was used to determine when tagged striped bass and Atlantic sturgeon were within the detection field of a given receiver [47,68]. Each detection event for a tagged fish was initiated when the individual first moved into the detection field and was recorded two times.…”