- Effectiveness of Venting and Recompression for Increasing Postrelease Survival of Barotraumatized Black Sea Bass across a Range of Depths , NORTH AMERICAN JOURNAL OF FISHERIES MANAGEMENT (2023)
- Identification of important forage fish and implications of increased predator demand through Ecopath modeling , ESTUARINE COASTAL AND SHELF SCIENCE (2023)
- Total mercury, methylmercury, and selenium concentrations in blue marlin Makaira nigricans from a long-term dataset in the western north Atlantic , SCIENCE OF THE TOTAL ENVIRONMENT (2023)
- Depredation of Demersal Reef Fishes Released with Descender Devices Is Uncommon off North Carolina, USA , NORTH AMERICAN JOURNAL OF FISHERIES MANAGEMENT (2022)
- Evaluation of six methods for external attachment of electronic tags to fish: assessment of tag retention, growth and fish welfare , JOURNAL OF FISH BIOLOGY (2022)
- Fine-scale behavior of red snapper (Lutjanus campechanus) around bait: approach distances, bait plume dynamics, and effective fishing area , CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES (2022)
- Computed Tomographic Assessment of Hooking-Related Injuries in Recreationally Angled Blue Marlin , JOURNAL OF AQUATIC ANIMAL HEALTH (2021)
- Discard Mortality of Red Snapper Released with Descender Devices in the US South Atlantic , MARINE AND COASTAL FISHERIES (2021)
- Environmental conditions, diel period, and fish size influence the horizontal and vertical movements of red snapper , SCIENTIFIC REPORTS (2021)
- Estimating discard mortality using meta-analysis and fishery-dependent sampling , FISHERIES RESEARCH (2021)
Previously collected trap and video data, along with ROV survey data, will be used to estimate red snapper abundance within an integrated population modeling framework. Population models require spatial replication over the study area of interest and temporal replicates that are independent but close enough in time to ensure population closure. The proposed study would use trap and video count data to estimate detection probability and abundance of red snapper within an integrated population model fitted in a Bayesian framework. Covariates that influence red snapper detection probability and abundance will be used to predict abundance (with associated uncertainty) at habitats that are similar to SEFIS sampling sites but not sampled. We will conduct workshops with reef fishery stakeholders to assist with identification of non-sampled hard bottom habitats. Based on past work, covariates important to red snapper abundance are likely to include bottom temperature, depth, latitude, and substrate type. A key question with this work is the spatial area that an individual SEFIS trap and video station effectively samples. The proposed project would address this question by estimating local abudance through a mark and resight approach using acoustic telemetry tags. Red snapper densities derived from ROV surveys will also be estimated at habitat types generally not sampled by SEFIS. Spatial maps of important covariates and habitat type will be used to generate abundance by area across the study region. These individual abundance values would be summed to estimate abundance of red snapper (with associated uncertainty) in the US Atlantic.
Development of a seasonal state-space, tag-integrated, size-structured assessment model with application to spotted seatrout stock in North Carolina and Virginia
This proposal is for a project that will evaluate fine- and broad- scale patterns in fish connectivity between and assemblages on artificial reefs and nearby natural hard-bottom reefs by harnessing advanced technologies.
Previously collected trap and video data, along with ROV survey data, will be used to estimate red snapper abundance within an integrated population modeling framework. Population models require spatial replication over the study area of interest and temporal replicates that are independent but close enough in time to ensure population closure. The proposed study would use trap and video count data to estimate detection probability and abundance of red snapper with an integrated populaiton model fitted in a Bayesian framework. Covariates that influence red snapper detection probability and abundance will be used to predict abundance (with associated uncertainty) at habitats that are similar to SEFIS sampling sites but not sampled. We will conduct workshops with reef fishery stakeholders to assist with identification of non-sampled hard bottom habitats. Based on past work, covariates important to red snapper abundance are likely to include bottom temperature, depth, latitude, and substrate type. A key question with this work is the spatial area that an individual SEFIS trap and video station effectively samples. Recently, project collaborators measured the response of red snapper around baited traps using fine spatial scale telemetry data, and response distance information will be used to estimate the sampled area at trap stations. Red snapper densities derived from ROV surveys will also be estimated at habitat types generally not sampled by SEFIS. Spatial maps of important covariates and habitat type will be used to generate abundance by area across the study region. These individual abundance values would be summed to estimate abundance of red snapper (with associated uncertainty) in the US Atlantic.
We have limited knowledge of the seasonal movements, stock structure (connectivity between Atlantic and Gulf of Mexico), and survival of greater amberjack. We propose to use acoustic telemetry to determine movement and stock structure of greater amberjack on the US Atlantic coast to aid in an estimation of abundance. Additionally, we would use a Cormack-Jolly-Seber mark-resight model to estimate survival of telemetry-tagged greater amberjack from detection histories gleaned from the large number and extensive geographic range of acoustic receivers in the US southeast. Greater amberjack (n=50 in each state) would be telemetry tagged in North Carolina, South Carolina, and Florida; acoustic receivers operated by the co-PIs in each of these regions as well as other regions would detect these telemetry-tagged amberjack. Our findings on greater amberjack movement, stock structure, mixing zones (Gulf of Mexico and Atlantic), and survival will be important for the next greater amberjack stock assessments.
This is a proposal to fund the North Carolina Marine Fisheries Fellowship Program. The Marine Fisheries Fellow program is currently sponsored by the North Carolina Division of Marine Fisheries (NCDMF) and North Carolina Sea Grant (NCSG). The program pairs M.S. or Ph.D. students or recent graduates with biologists within the NCDMF. The fellows that have taken part in this program have gained valuable experience working ÃƒÂ¢Ã¢â€šÂ¬Ã…â€œon the frontlinesÃƒÂ¢Ã¢â€šÂ¬Ã‚Â at a state fishery management agency. At the same time, NCDMF has benefited from results that are immediately applicable to management needs. Additionally, fellows have gone on to work with state and federal fishery management agencies or as university faculty. Results from past recipients provide examples of the success of this program and the benefits that the state would receive from continued support. Many results have had immediate impacts on habitat and fishery management plans. Specific examples include: an analysis of tagging data to estimate survival rates of striped mullet; juvenile abundance indices for white perch and yellow perch with an analysis of density-dependent loss; selectivity of red drum by gear type in the NC fishery; larval abundance indices for several winter-spawning estuarine-dependent species (e.g., southern flounder); identification of strategic habitat areas in the Albemarle sound and Pamlico Sound using fishery-independent sampling data; and an analysis of tagging data to estimate survival rates of stocked striped bass and migration strategies of wild striped bass.
Cobia are a large pelagic fish whose landings have increased in recent years due to its popularity with recreational anglers. Recent management issues with cobia have led to a call for more research on (1) subpopulations of cobia within the southeastern US (e.g. inshore-offshore migrations vs north-south migrations) and (2) the geographic boundary for southeastern US and Gulf of Mexico cobia stocks. Current research in Florida, Georgia, and South Carolina is using telemetry tagging and population genetics to address these questions. Our study would use similar methods to address questions about stock structure and philopatry in North Carolina and Virginia. Additionally, we would use a Cormack-Jolly-Seber mark-resight model to estimate survival of telemetry-tagged cobia from detection histories gleaned from the large number and extensive geographic range of acoustic receivers in the US southeast. This project would provide acoustic receivers in continental shelf waters of North Carolina to detect our telemetry-tagged cobia as well as telemetry-tagged cobia released in other states to our south. Our findings on cobia stock structure, mixing zones, and survival will be important for the next southeastern US cobia stock assessment.
Sheepshead (Archosargus probatocephalus) is an economically important species for North Carolina and around three quarters of annual landings come from recreational fishers. The management of sheepshead has recently been transferred from federal to individual state-level jurisdiction, because the fishery primarily operates nearshore. There has been no formal stock assessment of this species and NC lacks a fishery management plan. Currently, catch regulations are based on landings data because no index of abundance that is based on fishery independent data has been developed. Further complicating sheepshead management is a lack of life history information. In particular, the location and seasonality of spawning has not been identified in NC, and none of the state-run estuarine surveys effectively catch young-of-the-year sheepshead. Thus, understanding the dynamics of the spawning stock and annual recruitment are severely inhibited. The proposed research has two major components that will fill critical data gaps towards effective sheepshead management. The first step will be to analyze existing survey data from NC to characterize trends in sheepshead distribution and abundance. Two indices of annual abundance for adult sheepshead will be developed from long-term surveys that sampled both the nearshore continental shelf and estuarine habitats of NC. Further, habitat use of juvenile sheepshead will be characterized from multiple data sets from state and university conducted surveys from across NC. The second component of this work would be to identify two major spawning areas for sheepshead and determine the seasonality of reproduction. Previous coastal trawl surveys have identified two regions of sheepshead aggregation during spring when spawning is thought to occur. Based on the locations and timing from these surveys, we will sample possible sheepshead spawning locations by bottom trawl and take gonad samples from collected fish. These gonad samples will be processed for histological analysis to determine maturity stage and batch fecundity. Results from this work will provide two independent assessments of annual sheepshead abundance to help inform catch regulations. Further, the description of both spawning and nursery habitats will aid future efforts to monitor stock and recruitment trends of sheepshead in NC.
We will use capture-mark-recapture to provide data to determine whether release tools increase rates of post-release survival of black sea bass caught from deepwater habitats in the U.S. South Atlantic. There is high uncertainty regarding the effectiveness of different release tools (venting vs. descending) and we are not aware of work that has compared different venting tools. Existing literature recommends species-specific research to determine the effectiveness of these devices. It is logical that we work on black sea bass given the high percentage of releases (relative to fish captured) in the U.S. South Atlantic recreational fishery. The release tools that will be compared are a venting needle (16 g), venting tool (11 g), and a descender device. Tag return rates will be compared among these three release treatments and a control (untreated) group. Mark-recapture has been effective at informing robust statistical models of black sea bass survival in this region. We will catch, tag and release black sea bass over all seasons. Our work will occur over discrete depths and reefs where this species is found off North Carolina: ~20, 30, and 40 m deep. Black sea bass will be tagged in the dorsal musculature so they are not incidentally vented. Tag rewards will be offered for reported tags in order to increase return rates. Our analyses will focus on how experimental treatment type influences relative survival but will also estimate the effects of environmental, biological and researcher factors. We will do this by fitting Cox proportional hazards models, which allow one to evaluate the probability of occurrence of recapture and time to recapture for each marked fish. Our work will take place on both a charter vessel and a headboat; the former maximizes numbers of bass captured and recaptured while the latter maximizes opportunities to interact with the public and demonstrate the devices. Presentations will be given to the American Fisheries Society and the South Atlantic Fisheries Management Council to extend our results to research and management agencies. We will host a workshop (open to the public) where we will present results of our work and distribute experimental devices for use on private fishing operations.
Marine Protected Areas (MPAs) are thought of as a viable strategy for rebuilding stocks of reef fishes. However, little work has been done to validate the effectiveness of MPAs in the US southeast. The Snowy Wreck MPA (SWMPA) in North Carolina was designated as a closed area in 2009. Prior to closure (2007-08) the PIs of the proposed work performed a study in the SWMPA and an adjacent ÃƒÂ¢Ã¢â€šÂ¬Ã…â€œcontrolÃƒÂ¢Ã¢â€šÂ¬Ã‚Â area to evaluate the reef fish populations with fisheries acoustics and traditional gear (hook and line and chevron traps). The proposed work would repeat the prior study in both the SWMPA and the control area to examine whether the spatial closure substantially enhanced reef fish populations.