Comparing the hydrography and copepod community structure of the continental shelf ecosystems of Washington and Oregon, USA from 1998 to 2009 : can a single transect serve as an index of ocean conditions over a broader area?

• Main Author: Lamb, Jesse F
• Format: Dissertation
• Language: English
• Published: 23.03.2011
• Subjects: Chemical oceanography > Oregon > Pacific Coast; Chemical oceanography –- Washington (State) > Pacific Coast; Copepoda > Oregon > Pacific Coast; Copepoda > Washington (State) > Pacific Coast; Environmental sampling > Oregon > Pacific Coast; Environmental sampling –- Washington (State) > Pacific Coast; time-series; upwelling; zooplankton

Bi-weekly sampling of zooplankton and environmental parameters was conducted along a cross-shelf transect off the coast of Newport, OR, USA (44.65°N) from 1996 to present. Results have demonstrated the feasibility of using copepod community structure as an early indicator of ecosystem response to seasonal and large scale environmental changes in the Northeast Pacific. Spatial surveys of hydrography and zooplankton have also been completed along multiple cross-shelf transects from the central Oregon coast northward to the northwest corner of Washington (45-48°N) every May, June, and September since 1998. Although both sampling programs are located in the productive Northern California Current, questions have arisen as to the spatial comparability of zooplankton data, thus we tested the idea that data from a single transect can serve as an index of ocean conditions over a much broader area. That is, how feasible is it to make ecosystem forecasts from a single high-frequency data set (Newport) compared to more extensive but less frequent spatial surveys? Comparisons will be made using the environmental parameters (stratification, upwelling strength, chlorophyll concentration) and copepod community structure, including spatial variations and inter-annual variability. Regional analysis of environmental parameters allows insights into the relative importance of spatial variations in environmental variables in shaping copepod community structure and therefore the lower trophic level ecosystem.