Monitoring Relative Abundance of American Shad in Virginia’s Rivers 2000 Annual Report

Since the moratorium, there have been no monitoring programs that provided direct assessment of stock recovery until this project began in 1998. The ban on in-river fishing in Virginia remained in effect, creating a dilemma for managers who needed reliable information in order to make a rational decision on when the in-river ban could safely be lifted. To address this deficiency, we proposed a method of scientific monitoring to estimate catch rates relative to those recorded before the prohibition of in-river fishing in 1994. This monitoring program began in 1998 and consisted of sampling techniques and locations that were consistent with, and directly comparable to, those that generated historical logbook data collected by VIMS during the period 1980-1992 in the York, James and Rappahannock rivers. The results of the third year in the sampling program (2000) are reported in this document. The results of the first two years of sampling (1998 and 1999) are reported in previous annual reports (Olney and Hoenig 2000a, 2000b)

A general theory of age-length keys: combining the forward and inverse keys to estimate age composition from incomplete data

There are two approaches to estimating age composition from a large number of length observations and a limited number of age determinations: the forward and the inverse age-length keys. The forward key looks at the distribution of age within each length bin while the inverse key looks at the distribution of length at each age. The former is more precise but has stringent requirements for the way data are collected. The latter approach is more widely applicable. We review the theory of the two keys with particular attention to necessary assumptions and the restrictions on when the methods are applicable. We show it is possible to combine the two approaches into a combined forward-inverse age-length key. This approach can be used to estimate age composition in several years simultaneously. It takes advantage of the efficiency of the forward key in years when that is appropriate, applies the inverse key to years with no age data, and uses a blending of the two approaches for years with moderate amounts of age data

Monitoring Relative Abundance of American Shad in Virginia\u27s Rivers Annual Report 1999

A moratorium on the taking of American shad (Alosa sapidissima) in the Chesapeake Bay and its tributaries was established by the Virginia Marine Resources Commission (VMRC) beginning 1 January 1994. The prohibition applied to both recreational and commercial fishers. The moratorium was imposed at a time when commercial catch rates of American shad in Virginia\u27s rivers were experiencing declines. Data from the commercial fishery were the best available for assessing the status of individual stocks. Catch-per-unit-effort (CPUE) data were compiled from logbooks that recorded landings by commercial fishermen using staked gill nets at various locations throughout the middle reaches of the James, York and Rappahannock rivers. The logbooks were voluntarily provided to the Virginia Institute of Marine Science (VIMS) during the period 1980-1993, and subsequently used in an assessment ofthe status of American shad stocks along the Atlantic coast by the Atlantic States Marine Fisheries Commission (ASMFC) (ASMFC 1999). Since the moratorium, there have been no monitoring programs that provided direct assessment of stock recovery. The ban on in-river fishing in Virginia remained in effect, creating a dilemma for managers who needed reliable information in order to make a rational decision on when the in-river ban could safely be lifted. To address this deficiency, we proposed a method of scientific monitoring to estimate catch rates relative to those recorded before the prohibition of in-river fishing in 1994. This monitoring program began in 1998 and consisted of sampling techniques and locations that were consistent with, and directly comparable to, those that generated historical logbook data collected by VIMS during the period 1980-1993 in the York, James and Rappahannock rivers. The results of the second year in the sampling program (1999) are reported in this document. The results of the first year of sampling ( 1998) are reported in Olney and Hoenig (2000)

Evaluation of Striped Bass Stocks in Virginia: Monitoring and Tagging Studies, 2004-2008, 1 September 2005 - 31 August 2006

This report presents the results of striped bass (Morone saxatilis) tagging and monitoring activities in Virginia during the period 1 September 2005 through 31 August 2006. It includes an assessment of the biological characteristics of striped bass taken from the 2006 spring spawning run, estimates of annual survival and fishing mortality based on annual spring tagging, and the preliminary results of the fall 2005 study that documents the prevalence of mycobacterial infections of striped bass in Chesapeake Bay. The information contained in this report is required by the Atlantic States Marine Fisheries Commission and is used to implement a coordinated management plan for striped bass in Virginia, and along the eastern seaboard

A study of the river origin of American shad captured in the Atlantic Ocean intercept fishery in Virginia : Final report, 2001

The Virginia Department of Game and Inland Fisheries (VDGIF) has been releasing larval American shad into the James and York river systems since 1993 and these fish are given river-specific marks before release. Our in-river monitoring program had established that we could estimate the proportion of fish returning to spawn in the rivers that have hatchery marks. Furthermore, we were able to obtain a sample of 200 fish from the intercept fishery off Chincoteague Island, Virginia, in 2000 and screening of the otoliths by VDGIF personnel revealed the presence of one fish with a James River hatchery mark and one with a York River mark. No marks from any other river were found. Thus, it appeared that hatchery markings would allow the opportunity to estimate the proportion of Virginia stocks that were harvested in the offshore fishery. On the basis of these preliminary findings, we proposed the present study

Evaluation of striped bass stocks in Virginia : monitoring and tagging studies, 2004-2008 Annual report 1 September 2003 - 31 August 2004

This report presents the results of striped bass (Marone saxatilis) tagging and monitoring activities in Virginia during the period 1 August 2003 through 31 August 2004. It includes an assessment of the biological characteristics of striped bass taken from the 2004 spring spawning run, estimates of annual survival based on annual spring tagging, and the results of the fall 2003 directed mortality study that is a collaborative effort with the Maryland Department ofNatural Resources. The information contained in this report is required by the Atlantic States Marine Fisheries Commission and is used to implement a coordinated management plan for striped bass in Virginia, and along the eastern seaboard

Evaluation of striped bass stocks in Virginia : monitoring and tagging studies, 2004-2008 Annual report 1 September 2004 - 31 August 2005

This report presents the results of striped bass (Marone saxatilis) tagging and monitoring activities in Virginia during the period 1 September 2004 through 31 August 2005. It includes an assessment of the biological characteristics of striped bass taken from the 2005 spring spawning run, estimates of annual survival based on annual spring tagging, and the results of the fall 2004 directed mortality study that is a collaborative effort with the Maryland Department of Natural Resources. The information contained in this report is required by the Atlantic States Marine Fisheries Commission and is used to implement a coordinated management plan for striped bass in Virginia, and along the eastern seaboar

Evaluation of Striped Bass Stocks in Virginia: Monitoring and Tagging Studies, 2015-2019 Progress Report 1 September 2014 - 31 August 2015

This report presents the results of striped bass (Morone saxatilis) tagging and monitoring activities in Virginia during the period 1 September 2014 through 31 August 2015. It includes an assessment of the biological characteristics of striped bass taken from the 2015 spring spawning run and estimates of annual survival and fishing mortality based on annual spring tagging. Also included is information on gear selectivity of recreational anglers for striped bass. The information contained in this report is required by the Atlantic States Marine Fisheries Commission and is used to implement a coordinated management plan for striped bass in Virginia, and along the eastern seaboard

Evaluation of Striped Bass Stocks in Virginia: Monitoring and Tagging Studies, 2015-2019 : Progress Report 1 September 2015 - 31 August 2016

This report presents the results of striped bass (Morone saxatilis) tagging and monitoring activities in Virginia during the period 1 September 2015 through 31 August 2016. It includes an assessment of the biological characteristics of striped bass taken from the 2016 spring spawning run, estimates of annual survival and fishing mortality based on annual spring tagging, and the results of the study that documents the prevalence of mycobacterial infections of striped bass in Chesapeake Bay. Also included is an investigation on the potential use of close-kin analyses to determine the size of the spawning stock in the Rappahannock River. The information contained in this report is required by the Atlantic States Marine Fisheries Commission and is used to implement a coordinated management plan for striped bass in Virginia, and along the eastern seaboard