The concept of an ecosystem approach applied to the St. Lawrence Estuary (Canada) | Le concept d’approche écosystémique appliqué à l’estuaire maritime du Saint-Laurent (Canada)

For many years, operational frameworks to guide ecosystem-based science in support of integrated marine management have been sought to address causes of marine ecosystem degradation resulting from human activities such as fisheries, industrial development, aquaculture, etc. In 2007, the Canadian Department of Fisheries and Oceans developed several regional ecosystem research initiatives (ERI) to test and implement such approaches in order to support the integrated management of various human activities threatening ecosystem integrity. The St. Lawrence estuary, in Eastern Canada, hosted one of these ERI conducted from 2007 to 2012. The estuary is a high biological production area that supports a wide variety of human pressures and activities that might impact its integrity and sustainable use. Based on planning workshops that involved scientists as well as the main relevant managers of the region, two common priority issues were identified for the implementation of this ERI : (i) forage species responsible for the presence of blue whales in the lower St. Lawrence Estuary and (ii) characterization of the summer habitat of beluga whales in the St. Lawrence. The general objective of the St. Lawrence estuary ERI was to develop an operational framework for the coordination and integration of existing and new projects as well as ongoing monitoring programs to address several issues related to the two identified priorities and to provide integrated scientific information and advice (application of the ecosystem approach). The two themes led to an integrated scientific assessment that provided ecosystem-based advices in support of several management issues and conservation objectives at the scale of the ecosystem. Very valuable results were obtained for the Saguenay–St. Lawrence Marine Park, the implementation of recovery plans for species at risk (beluga and blue whale), and the anticipated establishment of a new marine protected area in the region. The objective of the manuscript is to describe the elements that justified the choice of the lower St. Lawrence Estuary as the study area and to present the implementation and some integrating results of the ecosystem research initiative in this region.