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Freshwater invertebrates [Diversity] [Generic richness] [Hydrographic units] [Water masses] [Depth] [Sediments] [Local richness] [Diversity and conservation] |
Marine invertebrates [Diversity] [Phylogeny] [Biogeography] [Aquatic physiographic units] [Depth] [Sediments] [Diversity of macrohabitats] [Diversity and conservation] |
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| Marine invertebrates of the St. Lawrence: diversity |
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A comprehensive spatial analysis of the diversity of marine invertebrates could not be carried out due to the lack of exhaustive local lists of species that cover the entire territory in question and are georeferenced. In fact, the best information on this highly diverse group came from the catalogue by Brunel, Bossé and Lamarche (1998), the most recent and complete regional compilation of the marine invertebrates of the estuary and Gulf of St. Lawrence. The catalogue consists of over 2,200 species of invertebrates, georeferenced for 20 broad biogeographic zones, and provides information on bathymetric distribution for 60% of species. The data taken from the catalogue were supplemented mainly by records of invertebrates from survey trawls for groundfish. These records consist of accurately georeferenced local lists of species, well distributed over the study area and obtained with a single type of well-described sampling gear. Invertebrate records obtained from trawl surveys are far from exhaustive, however, containing only records of a few suprabenthic and epibenthic species, generally large in size (macro or megabenthic). A phylogenetic and biogeographical approach was used in the analysis of the regional diversity of the marine invertebrates of the St. Lawrence. Diversity was analyzed at the scale of aquatic physiographic units and species' depth preferences, based on the bathymetric information in Brunel, Bossé and Lamarche (1998). Based on the sediment type, the physiographic units were subdivided further into macrohabitats and it was at this scale that richness was mapped. The conservation of marine invertebrates is discussed with reference to the results of these analyses and the main disturbances to the marine environment. Jacques Leclerc and Mathieu Cusson |
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