AZMP Anticosti Gyre
Gulf of St Lawrence
Latitude:   49.7200     Longitude:   -66.2500

 Associated Investigators:
Stephane Plourde (zoo) ,
Michael Scarratt (phyto) ,   Michel Starr (phyto) ,   Marjolaine Blais (bottle) ,   Peter Galbraith (CTD)  

Related Web Sites:
[Atlantic Zone Monitoring Program (AZMP)]   [St. Lawrence Global Observatory]  

Related Time Series:
[ Rimouski ]   [ Shediac Valley ]   [ Anticosti Gyre ]   [ Gaspé Current ]  

Update:   The AZMP Anticosti Gyre and Gaspé Current sites are no longer being visited on a bi-weekly basis. Limited continuation of these time series may be possible by using data from the twice-per-year sampling (June and November) by the AZMP "Section Sept-Iles" (TSI) spatial surveys.



The Atlantic Zone Monitoring Programme (AZMP) was implemented in 1998 with the aim of collecting and analysing the biological, chemical, and physical field data that are necessary to: (i) characterize and understand the causes of oceanic variability at the seasonal, interannual, and decadal scales; (ii) provide multidisciplinary datasets that can be used to establish relationships among the biological, chemical, and physical variables; and (iii) provide adequate data to support the sound development of ocean activities. The key element of AZMP sampling strategy is the oceanographic sampling at fixed stations and along sections. The fixed stations are occupied about every two weeks, conditions permitting, and the sections are sampled in June and November. Zooplankton are sampled from the bottom to the surface with a ringnet (0.75 m diameter, 200 µm mesh). CTD profiles are recorded, and samples for phytoplankton, nutrients, and extracted Chlorophyll are collected using Niskin bottles at fixed depths. Samples are combined to give an integrated sample. An ecosystem status report on the state of phytoplankton and zooplankton is prepared every year.

Data presented in this report are from two sampling stations in the northwest Gulf of St Lawrence (GSL, Figure 1): the Anticosti Gyre (AG, Figure 1) and the Gaspé Current (GC; Figure 1). The GSL is a coastal marine environment with a particularly high zooplankton biomass relative to other coastal areas, dominated by Calanus species (de Lafontaine et al., 1991). Annual anomalies of zooplankton biomass and abundance at GC and AG indicate that, in 2007, biomass was slightly lower than normal and abundance was above normal at both sites. Hierarchical community analysis revealed that copepods continue to numerically dominate the zooplankton year-round at both fixed stations in 2007, with the exception of a pulse of appendicularians that was observed during summer at AG and GC. There was no apparent change in copepod community structure in 2007 at either station.

Zooplankton abundance and biomass do not follow the same pattern as the concentration of Chlorophyll a. For example, the zooplankton peak observed at GC in 2003 corresponded to a Chlorophyll a minimum (Standard Co-sampled Variables Plot), whereas the Chlorophyll a peak at AG in 2001 corresponded to a zooplankton minimum (Standard Co-sampled Variables Plot). This absence of correlation between zooplankton and algal biomass has been observed in the GSL (de Lafontaine et al., 1991; Roy et al., 2000) and was attributed to the complex estuarine circulation pattern observed at GC and AG. Annual cycles of SST in both cases are similar, with values below 0 C in winter and peaks above 14 C during summer. Long-term SST values in the region (1900-2007) reveal that temperatures are currently at the high end of an approximately 50-year multidecadal trend and have been at, or above, the 100-year maximum (Standard Long-term Comparison Plot, red dashed line) since 1998. The exact effects of these high temperatures are not fully understood, although total zooplankton abundance at both regions is currently increasing with the increasing temperature at GC and AC.

REFERENCES:

de Lafontaine, Y., Demers, S., and Runge, J. 1991. Pelagic food web interactions and productivity in the Gulf of St Lawrence: a perspective, pp. 99-123. In The Gulf of St Lawrence: Small Ocean or Big Estuary? Ed. by J-C. Therriault. Canadian Special Publication of Fisheries and Aquatic Sciences, 113.


Roy, S., Silverberg, N., Romero, N., Deibel, D., Klein, B., Savenkoff, C., Vezina, A. F., et al. 2000. Importance of mesozooplankton feeding for the downward flux of biogenic carbon in the Gulf of St Lawrence (Canada). Deep-Sea Research II, 47: 519-544.