Browsing by Author "Jivoff, Paul"
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Item Assessment of Fish and Crab Responses to Human Alteration in Barnegat Bay(Trenton, N.J. : New Jersey Department of Environmental Protection, Division of Science, Research and Environmental Health, 2013) Able, Ken; Jivoff, Paul; Grothues, Thomas M.; Hagan, Roland; Belton, Thomas; Ferko, Marc; Ruppel, Bruce; Buchanan, Gary; Muffley, BrandonItem Assessment of Fish and Crab Responses to Human Alteration in Barnegat Bay(Trenton, N.J. : New Jersey Department of Environmental Protection, Division of Science, Research and Environmental Health, 2014-03-28) Able, Ken; Jivoff, Paul; Grothues, Thomas M.; Hagan, Roland; Belton, Thomas; Ferko, Marc; Ruppel, Bruce; Buchanan, Gary; Muffley, BrandonItem Assessment of Fish and Crab Responses to Human Alteration in Barnegat Bay : Barnegat Bay Final Report(Trenton, N.J. : New Jersey Department of Environmental Protection, Division of Science, Research and Environmental Health, 2015-09-29) Able, Ken; Jivoff, Paul; Grothues, Thomas M.; Hagan, Roland; Belton, Thomas; Ferko, Marc; Ruppel, Bruce; Buchanan, Gary; Muffley, BrandonItem Ecological Evaluation of Sedge Island Marine Conservation Area in Barnegat Bay : Final Report, 2013(Trenton, N.J. : New Jersey Department of Environmental Protection, Division of Science, Research and Environmental Health, 2013-08-21) Jivoff, Paul; Bilinski, Joseph; Belton, Thomas; Ferko, MarcConservation zones are important for maintaining the sustainability of ecosystems and populations of economically important species. The relative ecological value, especially for economically important species, of the Sedge Island Marine Conservation Zone (SIMCZ) in Barnegat Bay, NJ was assessed by comparing the following inside the SIMCZ with areas outside the conservation zone: (1) abundance and species diversity of fish and select decapod crustaceans in three habitats (seagrass, macroalgae, and unvegetated) using throw traps, (2) population structure of adult blue crabs using commercial-style traps, and (3) brood production of adult female blue crabs. Throw trap sampling indicates that blue crabs are most abundant in seagrass as compared to unvegetated habitats. Overall, blue crabs are more abundant outside the SIMCZ than inside but the difference does not apply to each habitat, suggesting the habitats inside and outside the SIMCZ are at least equivalent. Inside and outside the conservation area, species diversity is enhanced in both structured habitats as compared to unvegetated areas and is similar inside the SIMCZ as compared to outside. Again, this suggests the SIMCZ is at least equivalent to a comparative area outside the conservation zone. The SIMCZ has greater abundance of adult blue crabs, a sex ratio that is more skewed towards males, and a greater proportion of ovigerous females that are about to spawn and show signs of recent spawning. This suggests that the SIMCZ may provide refuge from fishing, particularly for male blue crabs, and may be an important area for spawning females.Item Ecological evaluation of Sedge Island Marine Conservation Area in Barnegat Bay : Final Report, 2014(Trenton, N.J. : New Jersey Department of Environmental Protection, Division of Science, Research and Environmental Health, 2014-08-29) Jivoff, Paul; Bilinski, Joseph; Belton, Thomas; Ferko, MarcConservation zones are important for maintaining the sustainability of ecosystems and populations of economically important species. The relative ecological value, especially for economically important species, of the Sedge Island Marine Conservation Zone (SIMCZ) in Barnegat Bay, NJ was assessed by comparing the following inside the SIMCZ with areas outside the conservation zone: (1) population structure of adult blue crabs using commercial-style traps, (2) reproductive potential of both sexes and brood production of adult female blue crabs, and (3) species diversity and abundance of fish and select decapod crustaceans, particularly blue crabs, in three habitats (seagrass, macroalgae, and unvegetated) using throw traps. Commercial-style trap sampling indicates that the SIMCZ had greater abundance of male blue crabs, a sex ratio that is more skewed towards males, and a greater proportion of ovigerous females than mid and western-bay locations outside the SIMCZ. There was no evidence that reproductive potential (e.g., sperm stores) or female brood production differed among the locations. Using a complementary data set from a co-occurring project; as compared with physically similar areas, the SIMCZ contained: (1) more adult blue crabs than other SAV-dominated areas along the north-south axis of Barnegat Bay, (2) more adult females, especially egg-bearing females, than adjacent, SAV-dominated areas with similar access to Barnegat Inlet, and (3) more male blue crabs than open bay habitats within an east-west zone of the Bay. Taken together, these results suggest that the SIMCZ is an important area for both male and female blue crabs, particularly females that are spawning. Throw trap sampling indicates that species diversity, the total abundance of organisms and the abundance of juvenile blue crabs were similar inside the SIMCZ as compared to outside the SIMCZ. In contrast, juveniles of two economically important fish species (winter and summer flounder) were more abundant inside the SIMCZ than outside the SIMCZ. Habitat was far more important than location in accounting for the variation in species diversity, total abundance and the abundance of blue crabs. In general, structured habitats (SAV and algae) contained more species, individual organisms and blue crabs than open areas. Sampling for this project occurred before and after “Superstorm” Sandy, thus annual differences may reflect potential Sandy effects. Annual differences in blue crab abundance between and within locations suggest that the SIMCZ provided a buffer against the potentially negative effects of Sandy. Throw trap sampling suggests that the SIMCZ contains habitats that are ecologically valuable and are helping to sustain valuable species.Item Ecological Evaluation of Sedge Island Marine Conservation Area in Barnegat Bay : Final Report, 2017(Trenton, N.J. : New Jersey Department of Environmental Protection, Division of Science, Research and Environmental Health, 2017-06-09) Jivoff, Paul; Bilinski, Joseph; Ferko, MarcConservation zones are important for maintaining the sustainability of ecosystems and populations of economically important species. In the third year of a three year study, the relative ecological value of the Sedge Island Marine Conservation Zone (SIMCZ) in Barnegat Bay, NJ was again assessed by comparing species diversity and abundance of fish and selected decapod crustaceans in three habitats (seagrass, algae, and unvegetated) inside the SIMCZ with an area outside the conservation zone. Long-term data sets are required to adequately assess the ecological value of conservation zones, thus, NJ-DEP staff and volunteers were trained in the field techniques to insure continued data collection in the future. Finally, based on results from previous years, the relative importance of the SIMCZ as a refuge against fishing pressure for adult blue crabs was tested using tag-recapture techniques. As in previous years, cylinder (i.e., throw trap) sampling indicates that species diversity, the total abundance of organisms and the abundance of juvenile blue crabs were similar inside the SIMCZ as compared to outside the SIMCZ. The few differences in abundance between the SIMCZ and outside the conservation zone may be attributed in part to relative proximity to the inlet. Habitat was far more important than location in accounting for the differences in species diversity and total abundance of organisms. In general, vegetated habitats (SAV and algae) contained more species, total organisms and several individual species than unvegetated areas. Evidence suggests that the SIMCZ contains habitats that are ecologically valuable and are helping to sustain valuable species. Finally, tagged crabs in the SIMCZ exhibited recapture rates higher than expected and days-at-large times shorter than expected suggesting the recreational fishing effort inside the SIMCZ may be higher than a comparable area with very little recreational (or commercial) fishing. Thus it may be prudent to collect information on recreational fishing activities occurring in the SIMCZ.Item Generator Cooling Water Effluent Restriction Effects of Oyster Creek Generating Station Closure on the Barnegat Bay Fish, Crab, and Infaunal Invertebrate Community(Trenton, N.J. : Department of Environmental Protection, Division of Science and Research, 2023-10-31) Grothues, Thomas; Jivoff, Paul; Piper, Sophia; Petrecca, Rose; Taghon, Gary; Able, KennethClosure of the Oyster Creek Nuclear Power Generating Station in Forked River, Lacey Township, NJ, in September of 2018 resulted in a 95% reduction of cooling water flow. Since cooling water was drawn from and discharged back into the Barnegat Bay near Barnegat Inlet, the historical effluent plume heated water with the potential to affect the thermal ecology of cold-blooded fish and invertebrates. The cooling water pumps also entrained larval fish and crabs directly and thus potentially affected the mortality of select species in the bay’s larval source pool. The effluent plume secondarily affected stratification and flow in the area through production of a warm, low-density, plume . Closure allowed a retrospective examination of these potential effects as well as provided a model for the sensitivity of the local fish and invertebrate community to climate change. This study leveraged previously collected samples of fish, crabs, and invertebrates from as far back as 2012 for comparison with recent sampling (2018-2021) in a Before/After Control/Impact design (for fishes and crabs) or a Before/After/Gradient design (for benthic infauna) to challenge the null hypothesis that there was no effect of closure and to quantify any noted effects relative to natural variation. Measures included abundance/distribution (for fishes, crabs and benthic infauna), assemblage change/beta diversity (for fishes and invertebrates), and size (for fishes) at different life stages as sampled by plankton net, otter trawl, crab traps, and gillnets. The strength of effects and the confidence in their measure was dependent on species and life stage, and for some there were no measurable effects. In all cases, BACI/BAG interactions (effects measured as different after closure in the Impact sites relative to their measure in the Control sites) were secondary to other sources of variation, including habitat, seasonal, and interannual variation, and spatial variation among the control sites. It is apparent that control site choice, as a function of measurement scale, affects the answer, pointing to a recognized and fundamental challenge in ecology. In retrospect, the plant was well sited because the spatial extent and persistence of the plume effects were dampened by regular tidal exchange with the ocean through Barnegat Inlet. Measured effects on sex-specific crab distribution and benthic invertebrate distribution and abundance decreased rapidly with distance from the discharge. Abundance was never seriously depressed (and was increased for adult fish) during operation in the Impact site, most likely because it was never source limited. Fish, benthic infauna, and many of the crabs utilizing the bay arrive from distant spawning sites as larvae, and many of the adult stages arrive as migrants; thus, local consumption by the plant was mitigated. Further, the life history of these species are adapted to and experience, individually and as populations, a greater annual and range-wide thermal variation than that produced by the generating station. This is a function of the station’s location near the apex of the Middle Atlantic Bight, and should be expected to differ from similar power-plant cooling water disturbances elsewhere in the country or world.