Fishery surveys typically reflect trends in abundance of the sampled population over time but are unable to estimate absolute abundance without knowledge of the efficiency of the sampling gear. If the efficiency of the gear is known, however, absolute estimates of abundance are possible. The VIMS Sea Scallop Research Program worked to estimate the efficiency of the sea scallop survey dredge used in fishery-independent resource surveys in 2008–2009 to allow biomass estimates of the sea scallop resource from dredge surveys.
Starting in 2016, spatially explicit biomass estimates of sea scallops in high-density areas have diverged between dredge surveys and optical surveys in the same areas.
To understand dredge efficiency, particularly at high sea scallop densities, several studies have been conducted in collaboration with NOAA, University of Delaware, and University of Massachusetts Dartmouth School for Marine Science and Technology:
- A Study to Assess the Effect of Tow Duration and Estimate Dredge Efficiency for the VIMS Sea Scallop Dredge Survey
- Paired Optical Dredge Tows with NOAA
- In Situ High-Definition Camera Monitoring to Evaluate Catch Efficiency and Performance of a Survey Dredge
- Understanding Dredge Performance for a Lined Versus Unlined NMFS Sea Scallop Dredge