Tiny lipid-rich crustaceans feed some of the Bay’s largest visitors
Nutrient rich, tidally driven waters in the Bay of Fundy support a tremendous zooplankton population and provide a predictable food supply for many of the creatures that inhabit this ecosystem. These small, free floating creatures are advected into dense patches where predators can feed upon them effectively. By far the most common species in the Bay is the copepod Calanus finmarchicus, which, over the course of the summer, increases to incredibly large patches. This small (1-2mm) crustacean is the preferred prey item of the highly endangered North Atlantic right whale, and is the reason why these animals congregate to Fundy during summer months. C. finmarchicus are also the main prey item of other important species like basking sharks and Atlantic herring.
Our zooplankton research is focused
on studying how the quality and composition of copepods changes from year to year, and how this influences the predators that rely on them. We use zooplankton nets to collect samples throughout the summer months. Back in the lab, we determine the energy content and biochemical composition of each sample and use this to examine how the quality of the prey base varies, both over a given summer as well as between summers. This allows us to evaluate whether predators coming to the Bay each summer will be able to meet their energy needs in a predictable fashion. So far we have discovered that the energy value of copepods varies significantly from year to year, which will affect foraging patterns and energy budgets of predators.