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Port Republic, NJ, United States

Able K.W.,Rutgers University | Grothues T.M.,Rutgers University | Turnure J.T.,Rutgers University | Byrne D.M.,Nacote Creek Research Station | Clerkin P.,Rutgers University
Fishery Bulletin

Distribution, movements, and habitat use of small (<46 cm, juveniles and individuals of unknown maturity) striped bass (Morone saxatilis) were investigated with multiple techniques and at multiple spatial scales (surveys and tag-recapture in the estuary and ocean, and telemetry in the estuary) over multiple years to determine the frequency and duration of use of non-natal estuaries. These unique comparisons suggest, at least in New Jersey, that smaller individuals (<20 cm) may disperse from natal estuaries and arrive in non-natal estuaries early in life and take up residence for several years. During this period of estuarine residence, individuals spend all seasons primarily in the low salinity portions of the estuary. At larger sizes, they then leave these non-natal estuaries to begin coastal migrations with those individuals from nurseries in natal estuaries. These composite observations of frequency and duration of habitat use indicate that non-natal estuaries may provide important habitat for a portion of the striped bass population. Source

Guerena K.B.,University of Delaware | Castelli P.M.,Nacote Creek Research Station | Nichols T.C.,201 County Route 631 | Williams C.K.,University of Delaware
Wildlife Society Bulletin

Disruption associated with nest visits during the hatch period of waterfowl can cause partial abandonment of hatchlings, potentially causing bias in the survival of marked birds. We evaluated the use of a mesh clutch-containment bag to capture and mark entire broods of 151 resident Canada goose (Branta canadensis) nests, prior to hatch, while minimizing observer-caused disruption during brooding. The study was conducted in New Jersey, USA, from April to June 2010. No differences were found in hatch success or the number of hatchlings marked between contained clutches and the control group. Although this technique was not beneficial in studying gosling survival in temperate nesting populations, it may be effective in subArctic nesting conditions where nest visits are conducted using a more invasive approach such as a helicopter. © 2012 The Wildlife Society. Source

Garrison L.P.,National Oceanic and Atmospheric Administration | Link J.S.,National Oceanic and Atmospheric Administration | Kilduff D.P.,University of California at Davis | Cieri M.D.,West Marine | And 5 more authors.
ICES Journal of Marine Science

Ecosystem-based fisheries management requires tools to place fish-stock dynamics in the broader context of fishery, predator, and competitive removals. Multispecies virtual population analysis (MSVPA) is an approach to quantifying predator-prey interactions and estimating the rates of predation mortality for exploited fish populations. Here, an extended MSVPA (MSVPA-X) is presented as an alternative to existing MSVPA approaches. Notably, MSVPA-X uses index-tuned VPA methods, applies a more flexible feeding model, and includes an alternative functional feeding response. The MSVPA-X model is applied to a western Atlantic fish community, focusing on Atlantic menhaden and its major fish predators, and a sensitivity analysis of major model parameters is presented. The sensitivity analysis highlights the need for adequate diet sampling. The MSVPA-X represents an improvement over previous approaches by increasing the flexibility to model seasonal and interannual dynamics in the strength of predator-prey interactions. Model results demonstrate that, for menhaden in particular, and forage fish in general, quantifying predation mortality is an important part of effective assessments of forage fish, their predators, and the fisheries of both. © 2009 International Council for the Exploration of the Sea. Published by Oxford Journals. All rights reserved. Source

Cramer D.M.,University of Delaware | Castelli P.M.,Nacote Creek Research Station | Yerkes T.,Ducks Unlimited Inc. | Williams C.K.,University of Delaware
Journal of Wildlife Management

Midwinter waterfowl survey data indicates a long-term decline in the number of wintering American black ducks (Anas rubripes), potentially due to habitat limitations. In order for future estimates of carrying capacity to be determined, it is critical that regional food availability is estimated. We collected pairs of habitat core samples (n = 510) from 5 habitat types in southern New Jersey, USA, during October, January, and April 2006-2008 to estimate resource availability and variability. We collected upper gastrointestinal tracts from hunter-killed birds (n = 45) and late season collections (n = 19) to identify food items and limited our estimates of resource availability to only winter food items; thereby reducing the availability of seed foods found in our core samples by 38% and animal foods by 96%. We did not detect differences in years or sampling period, but did between habitat types. Mudflat habitat had the greatest availability of invertebrate and vertebrate food items and appeared to supply the bulk of energy to black ducks wintering in southern New Jersey. We suggest conservation efforts to be focused on restoring or enhancing mudflat habitat as an integral component of an ecologically functioning salt marsh to increase food availability. © 2011 The Wildlife Society. Copyright © The Wildlife Society, 2011. Source

Wuenschel M.J.,Rutgers University | Able K.W.,Rutgers University | Vasslides J.M.,Rutgers University | Byrne D.M.,Nacote Creek Research Station
Fishery Bulletin

Piscivorous fishes, many of which are economically valuable, play an important role in marine ecosystems and have the potential to affect fish and invertebrate populations at lower trophic levels. Therefore, a quantitative understanding of the foraging ecology of piscivores is needed for ecosystem-based fishery management plans to be successful. Abundance and stomach contents of seasonally co-occurring piscivores were examined to determine overlap in resource use for Summer Flounder (Paralichthys dentatus; 206-670 mm total length [TL]), Weakfish (Cynoscion regalis; 80-565 mm TL), Bluefish (Pomatomus saltatrix; 55-732 mm fork length [FL]), and Striped Bass (Morone saxatilis; 422- 920 mm FL). We collected samples from monthly, fishery-independent trawl surveys conducted on the inner continental shelf (5-27 m) off New Jersey from June to October 2005. Fish abundances and overlaps in diet and habitat varied over this study period. A wide range of fish and invertebrate prey was consumed by each species. Diet composition (determined from 1997 stomachs with identifiable contents) varied with ontogeny (size) and indicated limited overlap between most of the species size classes examined. Although many prey categories were shared by the piscivores examined, different temporal and spatial patterns in habitat use seemed to alleviate potential competition for prey. Nevertheless, the degree of overlap in both fish distributions and diets increased severalfold in the fall as species left estuaries and migrated across and along the study area. Therefore, the transitional period of fall migration, when fish densities are higher than at other times of the year, may be critical for unraveling resource overlap for these seasonally migrant predators. Source

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