C S A S S C C S Canadian Science Advisory Secretariat Secrétariat canadien de consultation scientifique Research Document 2009/nnn Document de recherche 2009/nnn Rapport sur le status et les tendances Ecosystem status and trends report: de l’écosystème : ecozone de l’estuaire estuary and gulf of St. Lawrence et du golfe du Saint-Laurent ecozone Réjean Dufour 1, Hugues Benoît 2, Martin Castonguay 1, Joël Chassé 1, Laure Devine 1,Peter Galbraith 1, Michel Harvey 1, Pierre Larouche 1, Sylvie Lessard 1, Brian Petrie 3, Louise Savard 1, Claude Savenkoff 1, Liliane St-Amand 1 and Michel Starr 1 1 Department of Fisheries and Oceans Maurice-Lamontagne Institute, Mont-Joli, QC 2 Department of Fisheries and Oceans, Gulf Fisheries Centre, Moncton, NB 3 Department of Fisheries and Oceans, Bedford Institut of Oceanography, Darthmouth, NS This series documents the scientific basis for the La présente série documente les fondements evaluation of aquatic resources and ecosystems in scientifiques des évaluations des ressources et Canada. As such, it addresses the issues of the des écosystèmes aquatiques du Canada. Elle day in the time frames required and the traite des problèmes courants selon les documents it contains are not intended as échéanciers dictés. Les documents qu’elle definitive statements on the subjects addressed contient ne doivent pas être considérés comme but rather as progress reports on ongoing des énoncés définitifs sur les sujets traités, mais investigations. plutôt comme des rapports d’étape sur les études en cours. Research documents are produced in the official Les documents de recherche sont publiés dans language in which they are provided to the la langue officielle utilisée dans le manuscrit Secretariat. envoyé au Secrétariat. This document is available on the Internet at: Ce document est disponible sur l’Internet à: http://www.dfo-mpo.gc.ca/csas/ ISSN 1499-3848 (Printed / Imprimé) ISSN 1919-5044 (Online / En ligne) © Her Majesty the Queen in Right of Canada, 2009 © Sa Majesté la Reine du Chef du Canada, 2009 TABLE OF CONTENTS ABSTRACT ............................................................................................................................... V RÉSUMÉ ................................................................................................................................... V 1.0 INTRODUCTION.................................................................................................................. 7 2.0 PHYSICAL SYSTEM ........................................................................................................... 7 2.1 GEOMORPHOLOGIC STRUCTURE AND CHARACTERISTICS ..................................... 7 2.2 WATER MASSES ................................................................................................................. 8 2.3 SURFACE LAYER ................................................................................................................ 8 2.4 WINTER WATER MASSES , SEA ICE , SUMMER COLD INTERMEDIATE LAYER AND WINTER AIR TEMPERATURES .................................................................................................................. 9 2.5 DEEP LAYER TEMPERATURE, SALINITY AND DISSOLVED OXYGEN INTER -DECADAL VARIABILITY .11 2.6 WATER LEVEL ...................................................................................................................11 3.0 SOME ELEMENTS OF THE GULF ECOSYSTEM DYNAMICS..........................................11 3.1 SEASONAL BIOLOGICAL PRODUCTION CYCLES .....................................................................12 3.2 LOWER ESTUARY –GASPÉ CURRENT –SOUTHWESTERN GULF COMPLEX ................................12 3.3 NORTHWESTERN GULF (A NTICOSTI GYRE ) .........................................................................14 3.4 NORTHEASTERN GULF .......................................................................................................15 3.5 COASTAL ZONES ...............................................................................................................16 4.0 STATUS AND TRENDS OF PHYSICOCHEMICAL VARIABLES AND SELECTED SPECIES ...........................................................................................................................16 4.1 PHYSICOCHEMICAL VARIABLES .................................................................................16 4.1.1 Water quality and hypoxia ......................................................................................................... 16 4.1.2 Ocean acidification .................................................................................................................... 17 4.2 PHYTOPLANKTON ..............................................................................................................18 4.2.1 Trends in phytoplankton productivity ......................................................................................... 19 4.2.2 Trends in phytoplankton composition ........................................................................................ 19 4.2.3 Non indigenous planktonic species ........................................................................................... 19 4.2.4 Trends in harmful algal blooms (HAB)....................................................................................... 21 4.3 ZOOPLANKTON ..................................................................................................................21 4.3.1 AZMP Sections.......................................................................................................................... 22 4.3.2 Macrozooplankton ..................................................................................................................... 23 4.4 FISH AND MACROINVERTEBRATES ......................................................................................25 4.4.1 Estuary and Northern Gulf of St. Lawrence............................................................................... 25 4.4.2 Southern Gulf of St. Lawrence .................................................................................................. 26 Macroinvertebrates............................................................................................................................. 30 4.5 SEALS AND WHALES ..........................................................................................................31 4.5.1 Seals.......................................................................................................................................... 32 4.5.2 Whales....................................................................................................................................... 34 4.6 MARINE BIRDS ..................................................................................................................39 4.6.1 Population trends....................................................................................................................... 39 4.6.2 Biological indicators................................................................................................................... 41 5.0 CONTAMINANTS ...............................................................................................................43 5.1 CHEMICAL CONTAMINATION................................................................................................43 5.1.1 Sources, transport and distribution............................................................................................ 44 5.2 METALS ............................................................................................................................45 iii 5.3 PCB S AND OTHER ORGANOCHLORINE CONTAMINANTS .........................................................47 5.4 POLYCYCLIC AROMATIC HYDROCARBONS (PAH S)................................................................50 5.5 ORGANOMETALLIC COMPOUNDS .........................................................................................51 5.6 NEW CONTAMINANTS .........................................................................................................53 KEY HIGHLIGHTS ...................................................................................................................55 EMERGING ISSUES ................................................................................................................57 ACKNOWLEDGEMENTS.........................................................................................................58 REFERENCES .........................................................................................................................59 FIGURES..................................................................................................................................88 iv Correct citation for this publication: La présente publication doit être citée comme suit: 1Réjean Dufour, Hugues Benoît, Martin Castonguay, Joël Chassé, Laure Devine, Peter Galbraith, Michel Harvey, Pierre Larouche, Sylvie Lessard, Brian Petrie, Louise Savard, Claude Savenkoff, Liliane St-Amand and Michel Starr. 2009. Ecosystem status and trends report: estuary and gulf of St. Lawrence ecozone. DFO Can. Sci. Advis. Sec. Res. Doc. 2009/nnn. vi + xx p. 2Réjean Dufour, Hugues Benoît, Martin Castonguay, Joël Chassé, Laure Devine, Peter Galbraith, Michel Harvey, Pierre Larouche, Sylvie Lessard, Brian Petrie, Louise Savard, Claude Savenkoff, Liliane St-Amand and Michel Starr. 2009. Rapport sur le status et les tendances de l’écosystème : ecozone de l’estuaire