Data gathered from the monitoring program is used by researchers to assess the population of American shad and river herring in Virginia waters. The American shad and river herring monitoring program is the only available method to establish a catch index for adult populations. The information gathered contributes to the understanding and conservation of these important species.
Valuable information is gathered from the program such as:
- Spawning stock assessments
- Biological data on the spawning run (size, age-structure, sex ratio and spawning histories)
- Estimation of total mortality
- Biological characterization of permitted by-catch
- Evaluation of restoration programs by detection and enumeration of hatchery-released fish
- Relation of recruitment indices (young-of-the-year index of abundance) to relative year-class strength of spawning adults
- Examination of striped bass bycatch and incidental mortality rates
Studies of American shad and river herring in Virginia waters are significant to recreational fisheries for many reasons:
- American shad fight well when angled. Recreational fishing is popular in other states where fishing bans do not exist. Further development of a shad fishery could constitute an important opportunity to expand or restore recreational fishing opportunities.
- American shad and river herring are important for trophic and ecological reasons. The abundance of juveniles is closely linked to water quality and the availability of good fish habitat. Young shad and river herring constitute an important prey group for striped bass and other recreationally important species in the Chesapeake Bay. In recent years, there have been shifts in community structure in the major tributaries to the Bay with striped bass and gizzard shad numbers increasing greatly. Monitoring changes in abundance of key species is essential for understanding community dynamics.
- Until the moratorium took effect in 2012, river herring were recreationally harvested in Virginia's rivers. Lack of scientific data on the status of river herring stocks has been cited as a contributing factor for the inability to determine the sustainability of the stocks in Virginia, which led to the moratorium. This study addresses that shortcoming with the goal of informing management agencies for the objective of rebuilding river herring stocks to lift the moratorium.
- The proposed study will characterize the bycatch associated with commercial fisheries for American shad and river herring in Virginia's rivers. This is important for determining the impact of reopened commercial fisheries for shad and river herring on other recreationally important species, especially striped bass, as well as protected species such as Atlantic sturgeon.
- Considerable effort and sport fishing funds are being devoted to enhancement of shad stocks through hatchery programs. The monitoring program will provide an opportunity to identify returning hatchery fish. In 2003, a new hatchery-release program for American shad began on the Rappahannock River. This restoration effort is designed specifically for enhancement of recreational fishing and restoration of historic spawning habitat.