Testing the performance of a hydraulic clam dredge modified to capture small animals

• Main Authors: Hennen, Daniel Reneau, Mann, Roger Roger L., Charriere, Nicole, Nordahl, Victor A.
• Format: Text
• Language: unknown
• Published: U.S. Department of Commerce, National Oceanic and Atmospheric Administration, National Marine Fisheries Service, Northeast Fisheries Science Center 2016
• Subjects: Dredging Fisheries > Atlantic Coast U.S. > Equipment and supplies > Evaluation.; Arctica islandica; Ocean quahog
• Online Access: https://dx.doi.org/10.7289/v5m043dt; https://repository.library.noaa.gov/view/noaa/17255

The selectivity of the sampling gear used for the Northeast Fisheries Science Center’s clam survey for ocean quahog (Arctica islandica) and Atlantic surfclam (Spisula solidissima) is of particular interest because it is used to infer the abundance of small animals that are not efficiently caught. Small animals inform estimates of recruitment and are important indicators of stock health and productivity. A new selectivity dredge was designed and built in 2014 with the intention of improving the quantity and quality of selectivity experiments typically conducted during survey operations. Initial gear testing indicates that the new dredge will improve selectivity experiments. The new dredge filters unwanted material better than the previous one and can be towed for longer, resulting in a more representative sample of the experimental area. The previous dredge required several hours of shore side labor to prepare, while the new dredge does not. Finally, the size selectivity of the new dredge does not differ substantially from the previous one for Atlantic surfclam, but there are some differences for small and large ocean quahog.