Patterns of Hatchery-Produced Returns of American Shad in the James River, Virginia

American Shad Alosa sapidissima is an anadromous clupeid that once supported a robust fishery but has declined drastically throughout its native range due to overfishing, dam proliferation, and poor water quality. A hatchery program on the James River in Virginia was introduced in 1992 to support the recovery of stocks. Following a moratorium of the fishery enacted in 1994, a fisheries-independent survey was initiated in 1998 to monitor the population recovery efforts and status of American Shad stocks in Virginia. This paper examined 22 years of monitoring data for the James River and determined the effect of hatchery inputs on the James River stock of American Shad. The spawning stock index increased from 2.57 in 1998 to a peak of 9.33 in 2003 but has generally been declining since and has been at very low levels in most recent years. The hatchery prevalence for female American Shad (i.e., the percentage of fish derived from the hatchery) ranged between 3.6% and 60.5%. Years with higher spawning stock index values were significantly correlated to higher percentages of hatchery fish returning to spawn. The stock–recruitment relationship was best explained by the Ricker model, which had the lowest residual standard error and Akaike information criterion value. A threshold level of hatchery-released individuals (approximately 4 million larvae) was necessary to achieve the highest numbers of returning spawners, but stocking above 7 million larvae correlated with declining returns. Long-term monitoring of the James River American Shad spawning population allowed for the critical examination of the contribution of hatchery individuals to the yearly spawning run and the relative success rate of each hatchery year-class. From these data, we consider that the James River spawning stock of American Shad was dependent upon hatchery inputs, with ideal hatchery returns occurring during years of moderate levels of hatchery stocking

Monitoring the Abundance of American Shad and River Herring in Virginia’s Rivers 2020 Annual Report

This report describes the results of the twenty-third year of a continuing study to estimate the relative abundance and assess the status of American shad (Alosa sapidissima) stocks in Virginia by monitoring the spawning runs in the James, York and Rappahannock rivers in spring 2020, evaluating hatchery programs, and contributing to coast-wide assessments (ASMFC 2007, ASMFC 2020). We also report on two fisheryindependent monitoring programs using anchor gillnets in the Rappahannock River (year 3) and the Chickahominy River (year 6; a major tributary of the James River), to determine relative abundance and stock structure for the adult spawning run of river herring (A. pseudoharengus, and A. aestivalis). Further, we report on the year 5 of a monitoring program for juvenile alosines by using nighttime surface trawls in the Chickahominy River and present an index of juvenile abundance from this survey. Additional objectives were to monitor bycatch of American shad in a permitted gill-net fishery and American shad and river herring in pound-net fisheries

Monitoring the Abundance of American Shad and River Herring in Virginia’s Rivers 2022 Annual Report

This report describes the results of a continuing study to estimate the relative abundance and assess the status of American shad (Alosa sapidissima) stocks in Virginia by monitoring the spawning runs in the James, York and Rappahannock rivers in spring 2022, evaluating hatchery programs and contributing to coast-wide assessments (ASMFC 2007a; ASMFC 2020). We also report on a fishery-independent monitoring program to determine abundance and stock structure of river herring (A. pseudoharengus, and A. aestivalis) in Virginia by evaluating the adult spawning runs in the Chickahominy River, a major tributary of the James River, and the Rappahannock River. Further, a recently added objective of this study was to complement the monitoring of the adult spawning population of American shad and river herring in the James River system by monitoring juvenile alosines by using nighttime surface trawls in the Chickahominy River and calculate an index of juvenile abundance. Additional objectives were to monitor bycatch of American shad in a permitted gillnet fishery and American shad and river herring in pound net fisheries

Monitoring the Abundance of American Shad and River Herring in Virginia’s Rivers 2021 Annual Report

This report describes the results of the twenty-fourth year of a continuing study to estimate the relative abundance and assess the status of American shad (Alosa sapidissima) stocks in Virginia by monitoring the spawning runs in the James, York and Rappahannock rivers in spring 2021, evaluating hatchery programs, and contributing to coast-wide assessments (ASMFC 2007, ASMFC 2020). We also report on two fishery independent monitoring programs using anchor gillnets in the Rappahannock River (year 4) and the Chickahominy River (year 7; a major tributary of the James River), to determine relative abundance and stock structure for the adult spawning run of river herring (A. pseudoharengus, and A. aestivalis). Further, we report on the year 6 of a monitoring program for juvenile alosines by using nighttime surface trawls in the Chickahominy River and present an index of juvenile abundance from this survey. Additional objectives were to monitor bycatch of American shad in a permitted gill-net fishery and American shad and river herring in pound-net fisheries

Monitoring Relative Abundance of American Shad and River Herring in Virginia Rivers 2015 Annual Report

Concern about the decline in landings of American shad (Alosa sapidissima) along the Atlantic coast prompted the development of an interstate fisheries management plan (FMP) under the auspices of the Atlantic States Marine Fisheries Management Program (ASMFC 1999). Legislation enables imposition of federal sanctions on fishing in those states that fail to comply with the FMP. To be in compliance, coastal states are required to implement and maintain fishery-dependent and fishery-independent monitoring programs as specified by the FMP. For Virginia, these requirements include spawning stock assessments, the collection of biological data on the spawning run (e.g., age-structure, sex ratio, and spawning history), estimation of total mortality, indices of juvenile abundance, biological characterization of permitted by-catch and evaluation of restoration programs by detection and enumeration of hatchery-released fish. This annual report documents continued compliance with Federal law. Since 1998, scientists at the Virginia Institute of Marine Science have monitored the spawning run of American shad in the James, York and Rappahannock rivers. The information resulting from this program is reported annually to the ASMFC, has formed the basis for a significant number of technical papers published in the professional literature, formed the basis for a recent coast-wide stock assessment and peer review for American shad (ASMFC 2007a, 2007b) and is contributing substantially to our understanding of the status and conservation of this important species

Monitoring the Abundance of American Shad and River Herring in Virginia\u27s Rivers - 2016 Annual Report

This report describes the results of the nineteenth year of a continuing study to estimate the relative abundance and assess the status of American shad (Alosa sapidissima) stocks in Virginia by monitoring the spawning runs in the James, York and Rappahannock rivers in spring 2016, evaluating hatchery programs, and contributing to coast-wide assessments (ASMFC 2007). We also report on a new fishery-independent monitoring program using staked gillnets to determine relative abundance and stock structure for the adult spawning run of river herring (A. pseudoharengus, and A. aestivalis) in the Rappahannock River. Data are also reported from two separate fishery-independent monitoring programs using a drift gillnet (year 3) and anchor gillnets (year 2) to assess the status of the spawning run of river herring in the Chickahominy River, a major tributary of the James River. Further, we report on the second year of a monitoring program for juvenile alosines by using nighttime surface trawls in the Chickahominy River and calculate an index of juvenile abundance. Additional objectives were to monitor bycatch of American shad in a permitted gill-net fishery and American shad and river herring in pound-net fisheries

Monitoring the Abundance of American Shad and River Herring in Virginia\u27s Rivers - 2019 Annual Report

This report describes the results of the twenty-second year of a continuing study to estimate the relative abundance and assess the status of American shad (Alosa sapidissima) stocks in Virginia by monitoring the spawning runs in the James, York and Rappahannock rivers in spring 2019, evaluating hatchery programs, and contributing to coast-wide assessments (ASMFC 2007). We also report on two fishery-independent monitoring programs using anchor gillnets in the Rappahannock River (year 2) and the Chickahominy River (year 5; a major tributary of the James River), to determine relative abundance and stock structure for the adult spawning run of river herring (A. pseudoharengus, and A. aestivalis). Further, we report on the fourth year of a monitoring program for juvenile alosines by using nighttime surface trawls in the Chickahominy River and calculate an index of juvenile abundance. Additional objectives were to monitor bycatch of American shad in a permitted gill-net fishery and American shad and river herring in pound-net fisheries

Monitoring the Abundance of American Shad and River Herring in Virginia\u27s Rivers - 2018 Annual Report

This report describes the results of the twenty-first year of a continuing study to estimate the relative abundance and assess the status of American shad (Alosa sapidissima) stocks in Virginia by monitoring the spawning runs in the James, York and Rappahannock rivers in spring 2018, evaluating hatchery programs, and contributing to coast-wide assessments (ASMFC 2007). We also report on two fishery-independent monitoring programs using anchor gillnets in the Rappahannock River (year 1) and the Chickahominy River (year 4; a major tributary of the James River), to determine relative abundance and stock structure for the adult spawning run of river herring (A. pseudoharengus, and A. aestivalis). Further, we report on the third year of a monitoring program for juvenile alosines by using nighttime surface trawls in the Chickahominy River and calculate an index of juvenile abundance. Additional objectives were to monitor bycatch of American shad in a permitted gill-net fishery and American shad and river herring in pound-net fisheries

Developing Optimized Trajectories Derived from Mission and Thermo-Structural Constraints

In conjunction with NASA and the Department of Defense, the Johns Hopkins University Applied Physics Laboratory (JHU/APL) has been investigating analytical techniques to address many of the fundamental issues associated with solar exploration spacecraft and high-speed atmospheric vehicle systems. These issues include: thermo-structural response including the effects of thermal management via the use of surface optical properties for high-temperature composite structures; aerodynamics with the effects of non-equilibrium chemistry and gas radiation; and aero-thermodynamics with the effects of material ablation for a wide range of thermal protection system (TPS) materials. The need exists to integrate these discrete tools into a common framework that enables the investigation of interdisciplinary interactions (including analysis tool, applied load, and environment uncertainties) to provide high fidelity solutions. In addition to developing robust tools for the coupling of aerodynamically induced thermal and mechanical loads, JHU/APL has been studying the optimal design of high-speed vehicles as a function of their trajectory. Under traditional design methodology the optimization of system level mission parameters such as range and time of flight is performed independently of the optimization for thermal and mechanical constraints such as stress and temperature. A truly optimal trajectory should optimize over the entire range of mission and thermo-mechanical constraints. Under this research, a framework for the robust analysis of high-speed spacecraft and atmospheric vehicle systems has been developed. It has been built around a generic, loosely coupled framework such that a variety of readily available analysis tools can be used. The methodology immediately addresses many of the current analysis inadequacies and allows for future extension in order to handle more complex problems

Low-speed longitudinal aerodynamic characteristics of a flat-plate planform model of an advanced fighter configuration

A flat-plate wind tunnel model of an advanced fighter configuration was tested in the NASA LaRC Subsonic Basic Research Tunnel and the 16- by 24-inch Water Tunnel. The test objectives were to obtain and evaluate the low-speed longitudinal aerodynamic characteristics of a candidate configuration for the integration of several new innovative wing designs. The flat plate test allowed for the initial evaluation of the candidate planform and was designated as the baseline planform for the innovative wing design study. Low-speed longitudinal aerodynamic data were obtained over a range of freestream dynamic pressures from 7.5 psf to 30 psf (M = 0.07 to M = 0.14) and angles-of-attack from 0 to 40 deg. The aerodynamic data are presented in coefficient form for the lift, induced drag, and pitching moment. Flow-visualization results obtained were photographs of the flow pattern over the flat plate model in the water tunnel for angles-of-attack from 10 to 40 deg. The force and moment coefficients and the flow-visualization photographs showed the linear and nonlinear aerodynamic characteristics due to attached flow and vortical flow over the flat plate model. Comparison between experiment and linear theory showed good agreement for the lift and induced drag; however, the agreement was poor for the pitching moment