2014 to 2023 demersal fish abundance in the Estuary and the Gulf of St. Lawrence. The abundance is expressed as a number of individuals per normalized trawl set. Each species is individually represented in the northern Gulf and in the southern Gulf. Input data are from the annual August (North) and September (South) multidisciplinary surveys. The demersal species represented are: Alewife, Alligatorfish, American Plaice, Arctic Alligatorfish, Arctic Hookear Sculpin, Arctic Shanny, Arctic Staghorn Sculpin, Atlantic Cod, Atlantic Eelpout, Atlantic Halibut, Atlantic Hookear Sculpin, Atlantic Poacher, Atlantic Spiny Lumpsucker, Atlantic Wolffish, Black Dogfish, Blacksnout Seasnail, Brill/Windowpane, Common Grenadier, Common Wolf Eel, Cunner, Daubed Shanny, Esmark's Eelpout, Fish Doctor, Fourbeard Rockling, Fourline Snakeblenny, Greenland Cod, Greenland Halibut, Haddock, Longfin Hake, Longhorn Sculpin, Lowfin Snailfish, Monkfish, Goosefish, Moustache Sculpin, Newfoundland Eelpout, Northern Hagfish, Ocean Pout, Rockfishes, Sea Sculpin, Sea Tadpole, Shorthorn Sculpin, Smooth Skate, Snakeblenny, Spatulate Sculpin, Spiny Dogfish, Spinytail Skate, Spotted Wolffish, Stout Eelblenny, Thorny Skate, Twohorn Sculpin, Vahl's Eelpout, Variegated Snailfish, White Hake, Winter Flounder, Winter Skate, Witch Flounder, Wolf Eelpout, Wrymouth and Yellowtail Flounder. Purpose Since 1990, the Department of Fisheries and Oceans has been conducting an annual multidisciplinary survey in the Estuary and northern Gulf of St. Lawrence using a standardized protocol. In the southern Gulf of St. Lawrence, these bottom trawl surveys has been carrying out each September since 1971. These missions are an important source of information about the status of the marine ressources. The objectives of the surveys are multiple: to estimate the abundance and biomass of groundfish and invertebrates, to identify the spatial distribution and biological characteristics of these species, to monitor the biodiversity of the Estuary and Gulf and finally, to describe the environmental conditions observed in the area at the moment of the sampling. The southern Gulf surveys are realized using the following standardized protocol: Hurlbut,T. and D.Clay (eds) 1990. Protocols for Research Vessel Cruises within the Gulf Region (Demersal Fish) (1970-1987). Can. MS Rep. Fish. Aquat. Sci. No. 2082: 143p. The sampling protocols used for the Estuary and northern Gulf surveys are described in details in the following publications: Bourdages, H., Archambault, D., Bernier, B., Fréchet, A., Gauthier, J., Grégoire, F., Lambert, J., et Savard, L. 2010. Résultats préliminaires du relevé multidisciplinaire de poissons de fond et de crevette d’août 2009 dans le nord du golfe du Saint-Laurent. Rapp. stat. can. sci. halieut. aquat. 1226 : xii+ 72 p. Bourdages, H., Archambault, D., Morin, B., Fréchet, A., Savard, L., Grégoire, F., et Bérubé, M. 2003. Résultats préliminaires du relevé multidisciplinaire de poissons de fond et de crevette d’août 2003 dans le nord du golfe du Saint-Laurent. Secr. can. consult. sci. du MPO. Doc. rech. 2003/078. vi + 68 p. Annual reports are available at the Canadian Science Advisory Secretariat (CSAS), (http://www.dfo-mpo.gc.ca/csas-sccs/index-eng.htm). Bourdages, H., Brassard, C., Desgagnés, M., Galbraith, P., Gauthier, J., Légaré, B., Nozères, C. and Parent, E. 2017. Preliminary results from the groundfish and shrimp multidisciplinary survey in August 2016 in the Estuary and northern Gulf of St. Lawrence. DFO Can. Sci. Advis. Sec. Res. Doc. 2017/002. v + 87 p.

Identification of ecological and biological significant areas (EBSA) in the Estuary and the Gulf of St. Lawrence according to six groups of the food chain : primary production (Lavoie et al, 2007), secondary production (Plourde et McQuinn, 2010), meroplankton (Ouellet, 2007), benthic invertebrates (Chabot et al, 2007), demersal fishes (Castonguay et Valois, 2007) and pelagic fishes (McQuinn et al, 2012). The distribution area of each group has been evaluated using five criteria in order to determine the EBSA (DFO, 2004): 1. Uniqueness: Ranked from areas whose characteristics are unique, rare, distinct, and for which alternatives do not exist to areas whose characteristics are widespread with many areas which are similar. 2. Aggregation: Ranked from areas where most individuals of a species are aggregated to areas where individuals of the species are widespread 3. Fitness consequence: Ranked from areas where the life history activity(ies) undertaken make a major contribution to the fitness of the population or species present to areas where the life history activity(ies) undertaken make only marginal contributions to fitness. 4. Resilience: Ranked from areas where the habitat structures or species are highly sensitive, easily perturbed, and slow to recover to areas where the habitat structures or species are robust, resistant to perturbation, or readily return to the pre-perturbation state. 5. Naturalness: Ranked from areas which are pristine and characterized by native species to areas which are highly perturbed by anthropogenic activities and/or with high abundances of introduced or cultured species. Castonguay, M. and Valois, S. 2007. Zones d’importance écologique et biologique pour les poissons démersaux dans le nord du Golfe du Saint-Laurent. DFO Can. Sci. Advis. Sec. Res. Doc. 2007/014. iii + 34 p. Chabot, D., Rondeau A., Sainte-Marie B., Savard L., Surette T. et Archambault P. 2007. Distribution des invertébrés benthiques dans l’estuaire et le golfe du Saint-Laurent. DFO Can. Sci. Advis. Sec. Res. Doc. 2007/018. iii + 118 p. DFO, 2004. Identification of Ecologically and Biologically Significant Areas. DFO Can. Sci. Advis. Sec. Ecosystem Status Rep. 2004/006. Lavoie, D., Starr, M., Zakardjian, B. and Larouche, P. 2007. Identification of ecologically and biologically significant areas (EBSA) in the Estuary and Gulf of St. Lawrence: Primary production. DFO Can. Sci. Advis. Sec. Res. Doc. 2007/079. iii + 29 p. McQuinn, I.H., Bourassa, M-N., Tournois, C., Grégoire, F., and Baril, D. 2012. Ecologically and biologically significant areas in the Estuary and Gulf of St. Lawrence: small pelagic fishes. DFO Can. Sci. Advis. Sec. Res. Doc. 2012/087. iii + 76 p. Ouellet P. 2007. Contribution à l’identification de zones d’importance écologique et biologique (ZIEB) pour l’estuaire et le golfe du Saint-Laurent : La couche des oeufs et des larves de poissons et de crustacés décapodes. DFO Can. Sci. Advis. Sec. Res. Doc. 2007/011. iii + 76 p. (Mise à jour novembre 2010) Plourde, S. et McQuinn, I.A. 2010. Zones d’importance écologique et biologique dans le golfe du Saint-Laurent : zooplancton et production secondaire. DFO Can. Sci. Advis. Sec. Res. Doc. 2009/104. iv + 27 p.