Zooplankton community variability on the Scotian Shelf, northwest Atlantic

No abstracts are to be cited without prior reference to the author.

Marine zooplankton populations and communities are influenced by changes in local environmental conditions and ocean circulation. To provide information on how interannual changes in the pelagic environment and larger scale changes in circulation influence    zooplankton communities of the Scotian Shelf, in the Canadian northwest Atlantic, multivariate analyses were used to evaluate mesozooplankton species associations and large‐scale spatial patterns in zooplankton communities at both the Scotian Shelf scale and the larger Atlantic Canadian shelf scale. Depth and temperature associations were dominant factors structuring Atlantic Canadian shelf communities. Scotian Shelf species groups could be categorized as dominant shelf species, warm shelf species, Arctic Calanus species, and warm and cold offshore species. The abundance of immigrant groups, Arctic Calanus and warm offshore species, were strongly correlated with variability in temperature, while dynamics of the dominant species were more complex. While there is substantial uncertainty about how conditions on the Scotian Shelf will change in the future, the influence of the subtropical gyre may become greater, and it is likely that temperature will increase, salinity will decrease, and stratification will increase. Information on large‐scale zooplankton community patterns can provide insight into how species ranges and communities may change in the future.