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Zooplankton (& their environment) off Vancouver Island in 2005. Warm (but not a lot warmer than 2004) Chlorophyll & nutrients low (but enhanced by JdeF estuarine discharge) Zoop biomass below normal Zoop community composition similar to 1994-1998 (“southern” bias)
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Zooplankton (& their environment) off Vancouver Island in 2005 • Warm (but not a lot warmer than 2004) • Chlorophyll & nutrients low (but enhanced by JdeF estuarine discharge) • Zoop biomass below normal • Zoop community composition similar to 1994-1998 (“southern” bias) • Very poor seabird reproduction at Triangle Island colony (worst ever observed)
Zooplankton biomass • Below average but better than the mid 90s
Zooplankton Community Composition 2005 was: • Very bad for “boreal shelf” copepods • Good for “southern” copepods • Fair to poor for euphausiids, subarctic oceanic copepods, cool water chaetognaths
Some new “Southern” zooplankton (not the same mix as in 1990s) Acartia tonsa: • appeared in 2003 • now very abundant off SVI • has spread north to BC/AK border ‘Sagitta’ euneritica & minima now common Nyctiphanes simplex NOT detected off BC North South
Strong covariance of Zooplankton, Temperature, and “Predators” • “warm vs. cool” PC1 explains ~50% of normalized variance & correlations • Time series of PC1 was: (+) 1992-98 & 2003-05 (-) 1999-2002 (Mackas, Batten &Trudel MS