Small pelagic fish represent a critical trophic link between plankton and large predators in marine upwelling ecosystems such as the California Current System. Populations of these fish are highly variable over time and are characterized by extreme fluctuations in abundance, which have significant ecosystem impacts. The causes driving
this instability...
Ten high mountain ponds in Mount Rainier National Park, Washington State, were
studied from June through September 1992 to investigate the influences of fluctuating
pond volumes on zooplankton communities. A temporary pond of short wet phase
duration was inhabited by zooplankton taxa with short generation times and a crustacean
taxa...
Grazing rates and density of the crustacean zooplankton were measured
in Findley and Chester Morse Lakes and Lake Sammamish, Washington.
Sample analysis is incomplete at reporting time, thus estimates of
production from examination of life stage biomass changes was not possible.
Maximum density of crustacean zooplankton was about 10/1 in...
Zooplankton grazing rates and life history stage densities for secondary
production estimates were determined in three lakes in the Cedar River
watershed, Washington. Eight copepod species, seven cladoceran and nine
rotifer species were identified in the three lakes. No one species of
cladoceran or copepod occurred in all the lakes,...
Mangroves are becoming increasingly recognized as important nursery habitats for many juvenile fish and macroinvertebrate species, however little is known about their importance for zooplankton communities. The complex structure of mangrove environments may provide zooplankton populations with shelter, substrate, food, and protection from depredation. These factors could impact zooplankton survival,...
Recruitment of larvae from the plankton is an important determinant of
community structure in marine systems. In populations of many marine species,
recruitment determines the basic demographic parameters of immigration, emigration,
and reproduction. Moreover, the effect of recruitment as an "ecological subsidy" can
determine the strength of interactions among species...
Selected zooplankton from three oligotrophic lakes in Oregon were studied to determine whether or not their instantaneous birth rates and densities could be used in lake classification. The species of zooplankton studied in their respective lakes were Daphnia, pulex in Crater Lake, Daphnia longispina in Odell Lake, and Daphnia longispina...