Mapping horse mussel biogenic habitat in the Bay of Fundy
LE3 .A278 2020
Master of Science
Dense aggregations of horse mussels exist in the Bay of Fundy and are thought to be associated with high biodiversity compared to surrounding habitats. Previous research has found correlations between these aggregations (often referred to as reefs) and long narrow flow-parallel bedform features, but theories on the origin of these features vary. This study takes a multi-method approach using supervised and unsupervised classification methods to determine the distribution of these habitats and to assess broad-scale biophysical patterns and associated community assemblages of the horse mussel habitat and surrounding areas. MaxEnt was used to map habitat suitability at multiple scales in the area surrounding the flow parallel bedforms. Habitat suitability was best measured at 10 meters and not all flow parallel bedforms were found to be suitable habitat. These findings suggest, in contrast to previous studies, that not all bedforms contain horse mussel reefs. Seafloor images were compared to multibeam echosounder layers to further investigate community patterns and biodiversity. Overall community patterns shifted gradually across the Bay of Fundy and communities on and off the bedforms were found to be not discrete. Further analyses of the bedforms and surrounding areas suggested the abundance of horse mussels was significantly higher on the bedforms yet no significant differences in biodiversity were found. These findings will ultimately facilitate decisions around marine spatial planning, protection and monitoring of these areas.
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