Virginia Institute of Marine Science
The fisheries trawl survey conducted by the Virginia Institute of Marine Science (VIMS) is the oldest continuing trawl monitoring program (52 years) for marine and estuarine fishes in the United States. This survey provides a monthly baseline assessment of the abundance of juvenile marine and estuarine fishes and some invertebrates in the tidal and mainstem Chesapeake Bay. The survey provides crucial, real time data to various state, regional and national fisheries management agencies, including the Virginia Marine Resources Commission (VMRC), the Atlantic States Marine Fisheries Commission (ASMFC), the Mid-Atlantic Fisheries Management Council (MAFMC), and the National Marine Fisheries Service (NMFS). For example, the VIMS Trawl Survey provided the ASMFC with the only available index for spot, which was the cornerstone for the 2003 ASMFC Spot FMP. The MAFMC recognizes the VIMS Trawl Survey as the only available estimator of summer flounder recruitment, and recently the American eel index was vital to the 2006 ASMFC American Eel Management Plan. Several annual indices of juvenile abundance have been generated from trawl survey data for species of key recreational, commercial, and ecological importance in the Virginia portion of Chesapeake Bay. These include spot, Atlantic croaker, weakfish, summer flounder, black sea bass, scup, striped bass, white perch, white catfish, channel catfish, blue catfish, northern puffer, silver perch, blue crab, American eel, bay anchovy and Atlantic menhaden. Historically, four different estimates of relative abundance have been developed for juvenile finfish collected by this survey. However, only the unconverted indices (random stratified index – RSI, 1988 to present) for the target species discussed are the focus of this report. In recent years, juvenile indices for most species have declined, most often a result of overfishing, degradation of estuarine nursery habitats, and other natural environmental variation. For example, spot RSI indices have declined greatly over the past 50 years.Croaker show the greatest interannual variability of the key species discussed, with fluctuations likely related to weather. There has been an increasing trend in weakfish recruitment indices since 1994, while summer flounder have remained low, perhaps due to overfishing. The scup index has been highly variable and has increased slightly since 2004. Striped bass indices were very low during the 1970's and early 1980's, rebounded in the early 1990's and have decreased and remained low since 2001. White perch YOY and age 1+ indices decreased slightly in 2006 from the previous year. The white catfish YOY index increased in 2006 and the white catfish age 1+ index decreased slightly. The channel catfish YOY and age 1+ indices decreased in 2006. Both blue catfish indices (YOY and age 1+) have increased since 2001. Northern puffer indices have experienced a rapid and continuous decline since 1988. The silver perch index has remained consistently low over the study period. Both age 1+ and adult female blue crab indices exhibited significant declines. American eel and bay anchovy indices have also decreased since the 1980s. The newly created Atlantic menhaden index increased slightly in 2007. The Chesapeake Bay is a major nursery area for many coastal migratory fish species, and the data generated from this survey plays an integral role in management efforts along the Atlantic Coast of the United States.
fisheries, Management, Abundance, Virgina
This project was supported by the National Oceanographic and Atmospheric Administration, Fisheries Chesapeake Bay Program Office, Award No. NA03NMF4570378.
Fabrizio, M. C., & Montaine, M. M. (2007) Estimating Relative Juvenile Abundance of Ecologically Important Finfish and Invertebrates in the Virginia Portion of Chesapeake Bay (Award No. NA03NMF4570378) June 2003-May 2007. Virginia Institute of Marine Science, William & Mary. https://doi.org/10.25773/96MS-X013