To fully understand the dynamics of fish populations, the NOAA Chesapeake Bay Office works with partners to track trends in seasonal distribution and abundance of commercially, recreationally, and ecologically important finfish and invertebrates. To support these efforts, the NOAA Chesapeake Bay Office provides funding to support selected fisheries surveys in the Chesapeake.

The Chesapeake Bay Multispecies Monitoring and Assessment Program (ChesMMAP) is a fisheries independent trawl survey targeting late juvenile and adult fishes. The ChesMMAP survey area encompasses the main stem of the Chesapeake Bay from the mouth of the Bay north to Baltimore, Maryland. ChesMMAP runs five survey sessions a year (March, May, July, September, and November) each of which samples 80 stations.

The Bay is divided into five regions and stations are selected according to a random stratified design, incorporating both latitudinal and depth strata. At each station, a net is trawled along the bottom for 20 minutes, with the current, at a speed of 3.0-3.3 knots. All work is completed during daylight hours, and each session takes approximately eight working days to complete.

Taking subsamples of the catch for age determination allows for abundance indices to be developed. Taking subsamples for stomach content analysis would add the predator-prey relationships necessary for multispecies assessment models. Funding for ChesMMAP has been funded by the NOAA Chesapeake Bay Office and other partners since its inception in 2002.

Another survey—the Virginia Institute of Marine Science’s (VIMS) Juvenile Fish and Blue Crab Survey - has played an important role in researching and monitoring the Bay's fish populations since 1955. To support these efforts, the primary goal of the survey, often called the Virginia Trawl Survey, is to develop indices of abundance, which measure the relative size of each year class of a target species. These indices indicate annual recruitment success or failure and help predict the future abundance of the stock.

The data generated by the survey are used by fishery managers and researchers. These data, together with data from other surveys, are used by the state management agencies, such as the Virginia Marine Resources Commission, as well as multistate fishery management entities, like the Atlantic States Marine Fisheries Commission, to create fishery management plans.