K. Sherman et al., BIODIVERSITY AND ABUNDANCE OF THE ZOOPLANKTON OF THE NORTHEAST SHELF ECOSYSTEM, ICES journal of marine science (Print), 55(4), 1998, pp. 730-738
Since 1961, the Northeast Fisheries Science Center of the National Mar
ine Fisheries Service has been conducting a study of the zooplankton o
f the US Northeast Shelf ecosystem. One of the objectives is to invest
igate ecological patterns of the system for any evidence of regime shi
fts and their effects on biodiversity and abundance of zooplankton and
fish stocks. Two sampling strategies have been used: collections with
Continuous Plankton Recorders beginning in 1961; and collections with
bongo nets during the decade of MARMAP surveys (1977-1987), augmented
by a time series of collections made during the autumn and spring gro
undfish surveys (1977-1993). The climate regime of the region leads to
distinct and recurring seasonal pulses in zooplankton biomass and spe
cies succession in each of the four subareas of the shelf ecosystem di
stinguished. Evidence was detected in the analyses of inter-annual var
iability in species abundance and zooplankton biomass. However, no evi
dence of a large-scale regime shift of the magnitude described recentl
y for other areas was detected From our analyses. Species shifts in ab
undance and the inter-annual and decadal variability observed in zoopl
ankton biomass levels have allowed for sufficient residual sustainabil
ity in zooplankton biodiversity and abundance to support the recovery
of depleted pelagic fish stocks.