Geoscience Reference
In-Depth Information
their newborns for the first nine months of life. To do so, they need to exploit areas with high densities of
copepods, such as the Bay of Fundy. Fundy is a dual-purpose area, serving as a nursing or training ground for
young calves and as an important feeding ground for calves and mothers. Normally, right whales are skim
feeders: they simply plow along the surface through marine meadows of copepods, straining the tiny zooplank-
ton through their baleen plates. In the Grand Manan Basin, however, the whales employ a novel strategy, mak-
ing deep dives to exploit the copepod masses that are concentrated near the bottom by a combination of ocean
fronts and a local gyre that roughly follows the figure-eight shape of the Grand Manan Basin. Downwelling
occurs at the edge of the basin, where well-mixed and less well-mixed water masses converge. At this trans-
ition zone, the copepods settle out—in effect, they slide down the transition zone as down a pane of
glass—yielding a rich vein of the energy-rich zooplankton. Right whales' exploitation of the region is greatest
in August and September, to coincide with the peak pulses of copepod production.
