Spatial scaling of juvenile–adult associations in northwest Atlantic sea scallop Placopecten magellanicus populations

Abstract

High resolution images from 2008 and 2009 video surveys of Georges Bank and the Mid-Atlantic Bight were used to examine the association between juvenile and adult sea scallops over a range of spatial scales. Nearest neighbor and correlation analyses indicate that juvenile and adult scallops were negatively associated at small scales (cm) and positively associated at larger scales (>km) in both areas and years. However, the tipping point from negative to positive association occurred at a 10-to 100-fold larger spatial scale in the Mid-Atlantic than on Georges Bank. In both years, stronger negative correlation coefficients occurred in the Mid-Atlantic Bight. Differences between the Mid-Atlantic Bight and Georges Bank, with respect to larval supply, habitat quality and post-settlement movement and mortality are possible explanations that remain to be examined. The potential differences in population dynamics between these areas should be of interest to fishery managers and considered when devising harvest strategies in order to ensure the most efficient management of this valuable resource. This study presents an analysis method that has the potential to be a useful tool in understanding the spatial dynamics of populations and examining interactions both within and between species over a range of spatial scales.

Fertilization success in scallop aggregations: reconciling model predictions and field measurements of density effects

“…Scallop densities were observed over 14 research cruises at 12 different locations inside and outside closures in both GB and MA regions in 2008 and 2009 as in Carey et al. (). Since our interest was in the density of reproductive scallops, we confined our population density estimates to scallops ≥60 mm in SH, the size at which they fully empty their follicles during the spawning season (Davidson and Worms ).…”

“…), juvenile mortality (Wong and Barbeau ), and patchiness (Carey et al. ) have been studied intensively, the recent literature reflects a growing recognition of how little empirical information is available on the role of spawning and fertilization dynamics as potentially critical factors in successful recruitment of scallops (Stokesbury and Himmelman , Smith and Rago , Stokesbury , Harris et al. ).…”

Investigating uncertainties created by camera improvement in an optical survey

“…1, Table 1). This camera worked intermittently and was used opportunistically for specific projects (Harris and Stokesbury 2010; Carey and Stokesbury 2011; Carey et al 2013). In 2015, a Kongsberg® OE14‐408 digital still (Kongsberg) camera replaced the Nikon camera (Fig.…”