Drift of sea scallop larvae Placopecten magellanicus on Georges Bank: a model study of the roles of mean advection, larval behavior and larval origin

1994 ◽  
Vol 41 (1) ◽  
pp. 7-49 ◽  
Author(s):  
M. John Tremblay ◽  
John W. Loder ◽  
Francisco E. Werner ◽  
Christopher E. Naimie ◽  
Fred H. Page ◽  
...  
Keyword(s):  
Georges Bank ◽  
Placopecten Magellanicus ◽  
Larval Behavior ◽  
Sea Scallop ◽  
Model Study ◽  
Scallop Larvae

Planktonic Sea Scallop Larvae (Placopecten magellanicus) in the Georges Bank Region: Broadscale Distribution in Relation to Physical Oceanography

1992 ◽  
Vol 49 (8) ◽  
pp. 1597-1615 ◽  
Author(s):  
M. John Tremblay ◽  
Michael Sinclair
Keyword(s):  
Larval Abundance ◽  
Physical Oceanography ◽  
Georges Bank ◽  
Placopecten Magellanicus ◽  
Physical Processes ◽  
Scotian Shelf ◽  
Northern Flank ◽  
Sea Scallop ◽  
Scallop Larvae ◽  
The Mean

During autumn surveys for sea scallop larvae (Placopecten magellanicus) from 1985 to 1987, the mean abundance of sea scallop larvae on the northeast part of Georges Bank (1201–20080∙m−2) was much greater than on the southern Scotian Shelf (5–240∙m−2). Few larvae were collected between these two areas, and exchange between Georges Bank and the Scotian Shelf appears very limited. Transects across the northern flank in 1988 revealed peaks in larval abundance when on-bank temperature stratification was high. Relative larval abundance on the transects was positively related to the speed of the along-front current, suggesting physical convergence of larvae. The on-bank retention of scallop larvae on Georges Bank appears to be due to physical processes alone, since scallop larvae undertake only limited diel vertical migration. Larval exhange among adult scallop aggregations on Georges Bank (the northeast peak, the southeast part, and the South Channel) is probable, but evidence from this study is limited. The autumn production of late-stage larvae on the northern flank and northeast peak of Georges Bank is estimated to range from 120 to 1500∙m−2, which is 10–100 times greater than the density of scallops aged 1–2 yr.

Identification of Planktonic Sea Scallop Larvae (Placopecten magellanicus) (Gmelin)

1987 ◽  
Vol 44 (7) ◽  
pp. 1361-1366 ◽  
Author(s):  
M. J. Tremblay ◽  
L. D. Meade ◽  
G. V. Hurley
Keyword(s):  
Bay Of Fundy ◽  
Placopecten Magellanicus ◽  
Sea Scallop ◽  
Bivalve Larvae ◽  
Scallop Larvae ◽  
Shape And Size

Methods for the collection, processing, and identification of planktonic sea scallop larvae (Placopecten magellanicus) (Gmelin) are described. Bivalve larvae collected from the Bay of Fundy were compared with cultured P. magellanicus larvae. Sea scallop larvae collected from the plankton can be tentatively identified based on shape and size; examination of the larval hinge structure allows confirmation.

scholarly journals Dispersal and settlement of sea scallop larvae spawned in the fishery closed areas on Georges Bank

2009 ◽  
Vol 66 (10) ◽  
pp. 2155-2164 ◽  
Author(s):  
Rucheng C. Tian ◽  
Changsheng Chen ◽  
Kevin D. E. Stokesbury ◽  
Brian J. Rothschild ◽  
Geoffrey W. Cowles ◽  
...  
Keyword(s):  
Fishery Management ◽  
Ocean Model ◽  
High Rate ◽  
Georges Bank ◽  
Sea Scallop ◽  
Closed Area ◽  
Population Dynamics Model ◽  
Scallop Larvae ◽  
Simulation Based ◽  
Coastal Ocean Model

Abstract Tian, R. C., Chen, C., Stokesbury, K. D. E., Rothschild, B. J., Cowles, G. W., Xu, Q., Hu, S., Harris, B. P., and Marino II, M. C. 2009. Dispersal and settlement of sea scallop larvae spawned in the fishery closed areas on Georges Bank. – ICES Journal of Marine Science, 66: 2155–2164. Three fishery closed areas in the Georges Bank (GB) region were implemented in 1994 to protect depleted groundfish stocks for population replenishment. However, the drift and ultimate destination of larvae spawned in the closed areas have not been analysed specifically within the framework of ocean currents. To assess the efficiency of the closed areas as population replenishment sources, we conducted a simulation-based analysis on the dispersal and settlement of sea scallop larvae spawned in the closed areas from 1995 to 2005 using circulation fields computed by the Finite-Volume Coastal Ocean Model, scallop survey data, and a population dynamics model. Closed area I located in the Great Southern Channel (GSC) had a persistently high rate of larval retention (86% on average). For closed area II located on eastern GB, a considerable quantity of larvae was dispersed out of the domain. For the Nantucket Lightship Closed Area located on Nantucket Shoals, larvae consistently drifted away from the region during the 11 years simulated. Our simulation revealed three high-retention regions that are the most suitable for closed-area selection and rotational fishery management in terms of larval supply to the GB–GSC region.

Evaluating the interaction of the invasive tunicate Didemnum vexillum with the Atlantic sea scallop Placopecten magellanicus on open and closed fishing grounds of Georges Bank

2017 ◽  
Vol 74 (9) ◽  
pp. 2470-2479 ◽  
Author(s):  
Katherine A Kaplan ◽  
Deborah R Hart ◽  
Karen Hopkins ◽  
Scott Gallager ◽  
Amber York ◽  
...  
Keyword(s):  
Imaging System ◽  
Habitat Degradation ◽  
Negative Relationship ◽  
The United States ◽  
Georges Bank ◽  
Underwater Imaging ◽  
Placopecten Magellanicus ◽  
Didemnum Vexillum ◽  
Sea Scallop ◽  
Preferred Habitat

Abstract An invasive colonial tunicate (Didemnum vexillum) was initially observed on Georges Bank in 1998, and it has since spread in benthic environments on fishing grounds and areas closed to bottom-fishing. It can form dense mats on gravel substrates that are also a preferred habitat for the Atlantic sea scallop (Placopecten magellanicus), which supports one of the most valuable commercial fisheries in the United States. We used HabCam, a vessel-towed underwater imaging system, to investigate the spatial distributions of P. magellanicus and D. vexillum in a region that includes fishing grounds and an area protected from bottom-fishing. We found a negative relationship between P. magellanicus and D. vexillum, even after controlling for substrate and management status, suggesting that D. vexillum competes for habitat with P. magellanicus. We also applied the geostatistical method of universal kriging to interpolate the distribution of D. vexllium based on the covariables gravel, depth and area. Our results indicate that D. vexillum is more common in areas open to fishing than in the areas closed to fishing, even taking bottom substrate effects into account. Didemnum vexillum appears to have spread over portions of the northern edge of Georges Bank. This research evaluates potential fish and invertebrate habitat degradation caused by an invasive species.

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