Estimating Dredge Catch Efficiencies for the Northern Quahog (Mercenaria mercenaria) Population of Narragansett Bay
Document Type
Article
Publication Title
Journal of Shellfish Research
Publication Date
8-1-2020
Abstract
The catch efficiency of a hydraulic dredge was tested on a population of the northern quahog Mercenaria mercenaria in Narragansett Bay, RI, to understand gear limitations and correct relative abundance time series data. In 2017 and 2018, 45 hydraulic dredge tows were conducted following a long-standing fisheries-independent survey protocol, with the dredge transects inspected on SCUBA to assess dredge catch efficiency. Bull raking and quadrat samples taken on SCUBA were also conducted alongside the transects to compare sampling methods. The average dredge catch efficiency across samples was 0.64 (±0.29 SD). Bottom type was the most significant determinant of dredge catch efficiency, with higher catch efficiency on hard bottom (0.73 efficiency) than on soft bottom (0.48 efficiency). The quadrat and bull rake samples reflected higher catch rates than the dredge, but relationships between relative abundance estimates from the alternate methods and the dredge were either weak or insignificant. Bottom type, sediment classification, depth, and observed abundance were used to model dredge catch efficiencies and predict fisheries-independent abundance indices to more accurate estimates. Applying corrections using a generalized linear model scaled abundances through time, with trends generally the same between time series both with and without the corrections applied. This work provides an example of addressing gear efficiency concerns through diverse collaborations and improving the science and management for a commercially and recreationally significant marine resource.
Volume
39
Issue
2
Last Page
329
DOI
10.2983/035.039.0213
Recommended Citation
Conor McManus, M., Leavitt, D., Griffin, M., Erkan, D., Malek Mercer, A., & Heimann, T. (2020). Estimating Dredge Catch Efficiencies for the Northern Quahog (Mercenaria mercenaria) Population of Narragansett Bay. Journal of Shellfish Research, 39 (2) https://doi.org/10.2983/035.039.0213
ISSN
07308000
Funding Sponsor
Rhode Island Sea Grant, University of Rhode Island
Funding Number
RISG18-R/F-1618-30-1