Patterns of marine bird biodiversity and habitat use in the Gulf of Maine

Connelly, Emily Elizabeth (2014) Patterns of marine bird biodiversity and habitat use in the Gulf of Maine. Masters thesis, Memorial University of Newfoundland.

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Abstract

Vessel surveys of birds at sea provide important information about marine ecology and food webs. The Gulf of Maine and Scotian Shelf are productive habitats for seabirds that breed in both the Northern and Southern Hemispheres. I examined seabird vessel survey data from the 1980s through the 2000s in these areas during summer. My objective was to understand changes in seabird distributions, abundances, diversity and aggregations. Nonbreeding Southern Hemisphere species far outnumbered locally breeding species. Modeled habitat relationships for the dominant species showed that trans-equatorial Great Shearwaters (Puffinus gravis) were found in colder, deeper waters off the coast. A comparison of habitat use by Leach’s StormPetrels (Oceanodroma leucorhoa) and trans-equatorial migrant Wilson’s (Oceanites oceanicus) showed Leach’s Storm-Petrels closer to temperature fronts, but in lower chlorophyll density areas, while Wilson’s Storm-Petrels had no relationship to fronts or chlorophyll densities, but were seen in deeper more oceanic waters. Overall seabird numbers increased from the 1980s to the 2000s and species composition changed. Audubon’s Shearwaters (Puffinus lherminieri), Common Terns (Sterna hirundo), and Atlantic Puffins (Fratercula arctica) increased significantly, and Sooty Shearwaters (Puffinus griseus) declined significantly. Average taxonomic distinctness, a diversity measure used to indicate relatedness of a group of species, increased, showing greater distinctness (decreased relatedness) among seabirds studied. High species diversity, densities of seabirds, and endangered species use, e.g. Roseate Terns, identified key areas, such as the Jordan Basin, that warrant further investigation.

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