Since 1999, CBL Professor David Secor and his research team have conducted seine surveys off of the CBL research pier to measure seasonal variations in fish abundance and diversity in the Patuxent River.
To conduct each survey, Dr. Secor’s team pulls a 100-foot-long net through the waters along the pier, then identifies, counts, and measures the fish they pull in. They do this once a week, from mid-May to mid-October, collecting about 10,000 fish per year.
About 90% of the fish collected are silversides, bay anchovies, or menhaden. The other 10% includes spot, striped bass, white perch, bluefish, and blue crabs.
The survey has shown that changing temperatures from year to year affect the populations of different species. In the springs and summers following wet and cold winters, there are more blue crabs, striped bass, and white perch. Warmer winters lead to higher numbers of bluefish and spot.
Other factors that affect the populations of different species include how much water flows from tributaries to the Bay in the winter, spring temperature, and time of year.
The CBL pier also has the longest continuous record of temperature in the Chesapeake Bay. Since 1938, researchers have recorded data on temperature and other environmental conditions almost daily. According to their observations, the average temperature increased by 2.7° F over the first 70 years.
With the seine survey, researchers can observe how temperature impacts fish in the Patuxent River and predict the impacts future warming trends might have on the Chesapeake Bay and its fisheries.
