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

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.

Trait-based modeling of larval dispersal in the Gulf of Maine

“…Huret et al, 2007;Tian et al, 2009a) to tens of millions (e.g. Watson et al, 2012;Jones et al, 2015).…”

“…The four real-world species are sea scallops, Atlantic herring, yellowtail flounder (Pleuronectes ferruginea), and haddock. The sea scallop is a benthic, bivalve species with a moderate length PLD and active vertical swimming behavior (Tian et al, 2009a;Gilbert et al, 2010). Although both spring and fall spawning has been recorded in our study area, we only simulate spring spawning (Hart and Chute, 2004;Gilbert et al, 2010).…”

“…Within our study region, many of the most important spawning areas lie on Georges Bank or in the Great South Channel, and a number of studies have examined the processes that lead to successful dispersal for larval spawned within this region. Tian et al (2009a) simulated the dispersal of fall spawned sea scallop larvae from Georges Bank over an 11 year period from 1995-2005. They found that many of the larvae spawned between the 60 m and 100 m isobaths were retained over Georges Bank, and that 1995 was a particularly strong year for retention in the area (Tian et al, 2009a).…”

“…Tian et al (2009a) simulated the dispersal of fall spawned sea scallop larvae from Georges Bank over an 11 year period from 1995-2005. They found that many of the larvae spawned between the 60 m and 100 m isobaths were retained over Georges Bank, and that 1995 was a particularly strong year for retention in the area (Tian et al, 2009a). Ultimately, they concluded that scallop dispersal is primarily determined by the circulation patterns and locations of spawning populations, and that the strong tidal mixing recirculation was a major reason for the strong retention during 1995.…”

Effects of interannual environmental variability on the transport-retention dynamics in haddock, Melanogrammus aeglefinus larvae on Georges Bank

“…Individual-based models (IBMs) in corporate physical dynamics of the environment (circulation, ad vection, stratification, and turbulent mixing) with individual-and co hortlevel processes during the early life stages to infer relationships resolved in the model to ob served patterns in the field (Bartsch & Coombs 2004, Tian et al 2009). IBMs of cod and haddock larvae in the Gulf of Maine have relied pri marily on climatological circulation models, with variability in flow fields incorporated through the addition of monthlyaveraged wind-driven forcing (Werner et al 1993, Brickman & Frank 2000.…”