Southern Vancouver Island - Offshore
Canadian Pacific Coast
Latitude:   48.5000     Longitude:  -126.5000

 Associated Investigators:
Ian Perry ,
Moira Galbraith ,   Dave Mackas  

Related Time Series:
[ Northern Vancouver Island ]   [ Southern Vancouver Island ]   [ Line-P (OWS-P) ]  

Zooplankton time series coverage for the Vancouver Island continental margin extends from 1979-present for southern Vancouver Island (Mackas et al. 2001, 2006, 2007), and from 1990-present (but with low sampling intensity and taxonomic resolution 1991-1995) for northern Vancouver Island (Mackas et al. 2004, 2006).

Sampling consists of vertical net hauls with black bongo nets (0.25 m2 mouth area, 0.23 mm mesh aperture, TSK flowmeter) from near-bottom to surface on the continental shelf and upper slope, and from 250m to surface at deeper locations. Samples are preserved in 10% formalin : seawater, and abundance by species and stage derived from microscope counts. Biomass per species and sample is calculated by summation of (abundance) x (body size) (See Mackas et al. 2001 for additional details).

The grid of 'standard' sampling locations is shown in (Figure 1), although additional locations are included in within-time-period averages when they are available. Samples are classified into 5 statistical areas based on location and bottom depth. For southern Vancouver Island, there are three sub-regions: (a) the shelf break and slope (z>200m), (C) the Juan de Fuca eddy region north of Juan de Fuca canyon, and (b) the remainder of the SVI continental shelf. For northern Vancouver Island, there are two: shelf (<200m) and shelf break and slope (>200m).

Data from each sampling period are spatially averaged within each region (geometric mean), and sample-number-weighted averages of the survey means are used to calculate average seasonal cycles = climatologies (to 2005) for each region. Within-region, within-time-period anomalies are calculated as log(observation/climatology), and these are then averaged within year (and sometimes across groups of taxa and across adjoining spatial regions) to give the time series of annual anomalies.

References:

Mackas, D.L., Thomson, R.E., Galbraith, M., 2001. Changes in the zooplankton community of the British Columbia continental margin, and covariation with oceanographic conditions, 1985-1999. Canadian Journal Fisheries Aquatic Science 58, 685-702.


Mackas, D.L., W.T. Peterson and J.E. Zamon. 2004. Comparisons of interannual biomass anomalies of zooplankton communities along the continental margins of British Columbia and Oregon. Deep-Sea Res. II 51, 875-896.


Mackas, D.L., W.T. Peterson, M.D. Ohman, and B.E. Lavaniegos. 2006. Zooplankton anomalies in the California Current system before and during the warm ocean conditions of 2005 Geophys. Res. Lett. 33, L22S07, doi:10.1029/2006GL027930.


Mackas, D.L., S. Batten, and M. Trudel. 2007 in press. Effects on zooplankton of a warmer ocean: recent evidence from the Northeast Pacific. Progr. Oceanogr.