dc.contributor.author | Lacharite, Myriam | |
dc.date.accessioned | 2017-09-15T15:18:51Z | |
dc.date.available | 2017-09-15T15:18:51Z | |
dc.date.issued | 2017-09-15T15:18:51Z | |
dc.identifier.uri | http://hdl.handle.net/10222/73320 | |
dc.description.abstract | This thesis examines the role of the physical environment in influencing the abundance, composition and diversity of epibenthic megafaunal communities – i.e. organisms > 2-3 cm living on the seafloor – in deep waters on continental margins (>100 m). In particular, I examine the role of fine-scale substrate features (e.g. presence of cobbles, boulders), the shape of the seafloor at local scales (100 m – kilometers), and oceanographic properties (temperature, currents, water column structure) at broader spatial scales (1 – 100s km). Factors were assessed at varying spatial scales (< 1 m to 100s of km), and in various deep-water habitats on continental shelves (~75 – 530 m depth), in a submarine canyon (~650 – 850 m depth), and at the base of the continental slope (~1000 – 3000 m depth). Sampling tools for biological communities included a 4-year field experiment, optical imagery from high-definition video and photographic cameras, and epibenthic trawling surveys. At fine spatial scales (< 1 m), recruitment of 2 species of deep-water corals in a submarine canyon was influenced by substrate type, with a preference for hard substrate (Chapter 2). I suggested that recruitment is also dependent on reproductive mode in corals, which differed between species, and local hydrodynamics. To further examine the role of substrate at fine spatial scales, I developed an approach using optical imagery to estimate substrate complexity based on principles of computer vision (Chapter 3). At local scales (10 m – 1 km), using the approach I developed in Chapter 3, I determined the influence of variability in substrate types on epibenthic megafaunal community composition and diversity (Chapters 4 and 5). In contrast, megafaunal abundance was correlated with variability in geomorphometry and oceanographic properties (Chapter 5). At mesoscales (10 – 100s km), on a dynamic continental shelf influenced by a strong oceanographic front, community composition was best explained by oceanographic properties, especially spatial patterns in temperature (Chapter 6). This thesis provided new approaches (Chapters 3 and 6) to study deep benthic ecosystems, and described scale-specific species-environment relationships (Chapters 2, 4, 5 and 6) necessary to design sampling surveys in unexplored environments and establish conservation strategies. | en_US |
dc.language.iso | en | en_US |
dc.subject | Deep-sea | en_US |
dc.subject | Benthos | en_US |
dc.subject | Gulf of Maine | en_US |
dc.subject | Megafauna | en_US |
dc.subject | Submersible | en_US |
dc.title | Factors influencing the abundance, composition and diversity of deep-water benthic megafaunal communities | en_US |
dc.date.defence | 2016-08-10 | |
dc.contributor.department | Department of Oceanography | en_US |
dc.contributor.degree | Doctor of Philosophy | en_US |
dc.contributor.external-examiner | Dr. Anthony Grehan | en_US |
dc.contributor.graduate-coordinator | Dr. Daniel Kelley | en_US |
dc.contributor.thesis-reader | Dr. Jonathan Grant | en_US |
dc.contributor.thesis-reader | Dr. Keith Louden | en_US |
dc.contributor.thesis-reader | Dr. Peter Lawton | en_US |
dc.contributor.thesis-supervisor | Dr. Anna Metaxas | en_US |
dc.contributor.ethics-approval | Not Applicable | en_US |
dc.contributor.manuscripts | Yes | en_US |
dc.contributor.copyright-release | Yes | en_US |