2021 journal article
COMPARISON OF VISUAL SURVEYS VERSUS DREDGING FOR MONITORING BAY SCALLOPS (ARGOPECTEN IRRADIANS) IN SEAGRASS BEDS
JOURNAL OF SHELLFISH RESEARCH, 40(3), 511–517.
author keywords: bay scallops; Argopecten irradians; visual survey; scallop dredging
UN Sustainable Development Goal Categories
14. Life Below Water
(Web of Science; OpenAlex)
15. Life on Land
(Web of Science)
Source: Web Of Science
Added: January 24, 2022
ABSTRACT Bay scallops (Argopecten irradians), once a profitable fishery species in North Carolina, have declined in population size following harmful algal blooms in the late 1980s. To prepare for future scallop restoration efforts, appropriate survey methods should be identified to evaluate the status of the population with respect to managing harvest. The North Carolina Division of Marine Fisheries monitors bay scallop populations in seagrass beds using a scallop dredge, though it is still unclear what the current natural densities of bay scallops are. In this study, visual surveys in three time treatments (5, 10, and 20 min) were compared with dredging in terms of quantifying scallop density and the catch per unit effort (CPUE) in seagrass beds in Core Sound, North Carolina. There was no significant difference in scallop density and the CPUE among visual survey time treatments. Scallop densities observed during visual surveys were three times higher than densities using a scallop dredge; however, the CPUE was five times higher using a scallop dredge compared with visual surveys. If visual surveys indicate the true natural density of bay scallops in this study system, then the dredge sampling efficiency for evaluating bay scallop density was 33%. Dredging for bay scallops can uproot seagrass and displace juvenile bay scallops. Visual surveys provide a low-impact method for identifying the distribution and abundance of bay scallops in seagrass bed habitats.