Spatio-temporal mapping of sub-Arctic benthic communities

• Main Author: Charmley, Kaitlyn
• Format: Thesis
• Language: English
• Published: Memorial University of Newfoundland 2023
• Subjects: Arctic; Chionoecetes opilio; Snow crab
• Online Access: https://research.library.mun.ca/16256/; https://research.library.mun.ca/16256/1/thesis.pdf

Spatial studies of benthic communities rarely incorporate a temporal aspect into their construction, despite the fact that organisms can exhibit spatio-temporal patterns. Construction of benthic community maps often involve the association of spatially-continuous acoustic layers with in situ samples (ground-truthing); often image and/or video data. Most current habitat mapping studies are built from a single ground-truthing event, which makes the maps a simple snapshot of the distribution of organisms and does not consider temporal variability. The goal of this thesis was to explore the importance of incorporating seasonality into investigations on benthic organisms habitat selection, at both the community and species levels. The first objective explores the spatio-temporal changes that occur in the communities and the implications in the production of benthic community maps. The second objective focuses on one economically-important species, snow crab (Chionoecetes opilio) and investigates the abiotic factors influencing its habitat selection and how these drivers change seasonally. The community maps produced in part one presented two to five different communities depending on the season, with map differences caused by the changes in densities and location of individual taxa. Part two revealed that fine-scale habitat preferences of snow crab was driven by temperature, slope, and in the winter, seafloor hardness. Recommendations are made to researchers regarding timing and frequency of ground-truthing data collection. This study is one of the first to produce predictive maps based on a spatio-temporal seafloor dataset for a sub-Arctic megabenthic community in Canada. It emphasized the importance of incorporating temporal coverage into benthic research to accurately represent communities. This will increase the effectiveness of management of these marine areas , so they can remain biodiverse and economically productive.