scholarly journals Sea scallop larvae Placopecten magellanicus on Georges Bank: vertical distribution in relation to water column stratification and food

1990 ◽  
Vol 61 ◽  
pp. 1-15 ◽  
Author(s):  
MJ Tremblay ◽  
M Sinclair
1992 ◽  
Vol 49 (8) ◽  
pp. 1597-1615 ◽  
Author(s):  
M. John Tremblay ◽  
Michael Sinclair

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.


1987 ◽  
Vol 44 (7) ◽  
pp. 1361-1366 ◽  
Author(s):  
M. J. Tremblay ◽  
L. D. Meade ◽  
G. V. Hurley

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.


2009 ◽  
Vol 66 (10) ◽  
pp. 2155-2164 ◽  
Author(s):  
Rucheng C. Tian ◽  
Changsheng Chen ◽  
Kevin D. E. Stokesbury ◽  
Brian J. Rothschild ◽  
Geoffrey W. Cowles ◽  
...  

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.


Sign in / Sign up

Export Citation Format

Share Document