Harvesters Help Find Quahogs

From Rhode Island Sea Grant

Dale Leavitt, a researcher and faculty member at Roger Williams University, has calibrated bullrakes used by commercial clam harvesters to compare assessments made by hydraulic dredges used by RI Department of Environmental Management to assess population.

This is the first part of research to better understand where quahogs in the Bay come from and travel to manage potential spawning and settlement areas.

“We wanted to look at assessment tools to take advantage of the commercial fishing fleet and see if there was an alternative for stock assessment,” said Leavitt in a presentation at the Shellfish Management Plan stakeholder meeting in April. “But we needed to see if a bullrake could be used to give accurate measurements.”

The trick, Leavitt said, is knowing how much of the bottom was sampled by a bullrake to make accurate comparisons with a hydraulic dredge used by RI DEM. In order to do that, Leavitt has found a way to “calibrate” harvesters so their data seamlessly meshed with those of RI DEM.

This new methodology allows commercial quahoggers to collect scientifically valid population assessment data and present that for use in official state stock assessments.

Research will continue this summer and will also look at circulation patters to predict quahog dispersal.

This project is supported by RI Sea Grant, the Commercial Fisheries Research Foundation (CFRF) and the Southern New England Collaborative Research Initiative (SNECRI).