Hudson bay ecosystem: Past, present, and future

Abstract

In order to gain insight into the dynamics of the Hudson Bay ecosystem as well as past and future states, an ecosystem model was created using a static Ecopath model to represent the present day ecosystem in Hudson Bay. Simulations of past and future ecosystem states were used to gain insight to key trophic linkages within the system, with focus on marine mammal populations. The past ecosystem was simulated by increasing ice algae and removing killer whales (Orcinus orca) from the system, which led to an increased biomass of all other groups within the model, excluding pelagic producers. Future states of Hudson Bay are presented in three scenarios representing various degrees of reported and predicted ecosystem changes including climate change and increased hunting pressure. All future scenarios show an overall decrease in species biomass, although some species are positively impacted by the changes in the system. Model simulations suggest bottom up forcing of ice algae is an important factor driving marine mammal biomass. © 2010 Springer Netherlands.