Chesapeake Bay Oyster Population Estimate (CBOPE)

One of the principal goals of the Chesapeake 2000 Agreement was a 10-fold increase in the Bay oyster population by 2010. The baseline for this goal is the oyster population biomass that existed at the beginning of 1994, as assessed by surveys in fall 1993. In 2000, the NOAA Chesapeake Bay Stock Assessment Committee and the US EPA Chesapeake Bay Program jointly funded an interstate research project for the purposes of (1) quantifying the baseline oyster population, and (2) establishing the monitoring, data management and data analysis frameworks for measuring progress toward the oyster restoration goal, Chesapeake Bay Oyster Population Estimation or CBOPE. This collaborative project between Maryland and Virginia partners has produced to date annual estimates of Chesapeake Bay oyster populations for the period 1994-2002 (MD) and 1994-2003 (VA). Using the formats established by the CBOPE project, annual tracking of progress towards the 2010 goal will continue.

Each state has identified distinct basins or water bodies as well as sentinel sites within the Chesapeake Bay that will be used to estimate abundance and biomass of Chesapeake oyster populations. Annual oyster population estimates for basins provide evidence of geographic trends within watersheds. The term "sentinel site" is applied to individual sites where oyster populations have been, or henceforth will be, monitored annually. Data from these sites may provide an index of restoration or replenishment success in relation to both basin and technique.

Basin Estimates

For convenience and ease of data presentation, Chesapeake Bay tributaries within each state were assigned to basins. Basins correspond approximately with watersheds. Within a basin, oyster population data were combined to provide basin wide estimates of total oyster numbers and oyster population biomass.

Sentinal Site Estimates

Sentinel sites have been established in tributaries of the Chesapeake Bay to facilitate monitoring of oyster populations at specific locations over time. The term sentinel site is used to describe a monitoring station for which long-term monitoring data are available.

Project Partners

This project has been a collaboration between the following agencies and institutions:

This project has been sponsored by: