Comparison of Month-to-Month Patterns of Abundance and Vertical Distributions of Pseudocalanus spp. in Five Regions of Georges Bank During 1999 Broadscale Surveys

Bucklin. A.1, H.H. Wiebe2 and D.J. McGillicuddy3
1University of New Hampshire
2Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA 02543
3Applied Ocean Physics & Engineering Department, Woods Hole Oceanographic Institution, Woods Hole, MA 02543

The cryptic copepods, Pseudocalanus moultoni and P. newmani, exhibit different month-to-month patterns of abundance and vertical distribution in the different regions of Georges Bank. Using the standard grid designed for the Northwest Atlantic synthesis phase activities, concentrations of females for each species were mapped for three depth strata: surface (0 - 15m), sub-surface (15 - 40m), and deep (below 40m). Broadscale standard stations were assorted into five regions of Georges Bank: 1) northern flank, 2) Bank crest, 3) northeast peak, 4) southern flank, and 5) Slope Water. During stratified conditions (April to June), a significantly greater proportion of P. newmani are found in surface waters, where they are subject to wind-driven transport. The preference of P. moultoni for deeper waters was most pronounced during May and June and in two regions, Bank crest and northeast peak. Concentration of P. moultoni in deeper waters may increase the likelihood of retention of these populations on Georges Bank.

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