Grant: Discovery Grants Program - Group

Understanding the dynamics of large marine ecosystems faced with exploitation and climate variability remains one of the key challenges within marine ecology, with direct implications for fisheries management and the economic welfare of coastal communities. Yet there remains no comprehensive explanation for the observed state of Northwest Atlantic marine ecosystems, or the variable rebuilding rates of depleted stocks. This indicates that existing population and ecosystem models are missing key ecological or behavioural mechanisms. With a focus on marine ecosystems of Newfoundland and Labrador, it is these mechanisms that the proposed collaborative research will pursue towards the team's shared long-term goal of providing predictive population and ecosystem models of key pelagic and benthic fish species, and invertebrates. At the individual and population levels, both the implications of commercial fish and invertebrate mating systems and the life-history variability of marine species at-risk will be quantified using experiments and survey data, while novel chemical analyses of marine fish ear bones will be used to reconstruct past feeding and habitat use by individual fishes. At the food web level, the potential roles of variable rates of prey production constraining the recovery of top predators, spatial overlap between species differentially influenced by changing oceanographic conditions, and whether local water temperature differences influence the resilience of food web interactions as in comparisons among ecosystems, will provide novel insights on the importance of species interactions, and the extent that climate mediates these interactions. Finally, the implications of strong climate influences on sub-Arctic ecosystems will be tested empirically, in the context of an ecological theory that seeks to link climate forcing, population dynamics and ecosystem functioning. Depleted fish stocks and ecosystems represent latent fisheries and economic productivity. This research will contribute to the expanding field of ecosystem-based fisheries management, which is expected to play an increasing role in future marine management decisions and policy directions.