Evaluating British Columbia’s artificial reefs in a conservation context

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dc.contributor.author Bulger, Desirée
dc.date.accessioned 2019-05-01T18:22:09Z
dc.date.available 2019-05-01T18:22:09Z
dc.date.copyright 2019 en_US
dc.date.issued 2019-05-01
dc.identifier.uri http://hdl.handle.net/1828/10823
dc.description.abstract Synthetic marine habitats such as artificial reefs (ARs) are deployed to offset marine habitat losses and aid conservation of marine communities, including species at risk. Though environmental benefit is often assumed, AR’s ability to support northern temperate marine fish communities has rarely been tested. The structural orientation and location of a reef can strongly influence biodiversity and productivity of faunal communities inhabiting it. For ARs, understanding how reef characteristics affect species and community composition are key in optimizing their use in conservation initiatives. I used ROV and sonar to survey threatened rockfish (Sebastes spp.) and other groundfish species associated with 18 ARs and natural reefs (NRs) along the northeast Pacific coastal shelf, along the coast of BC, Canada. In my second chapter, I investigate how ARs compare to NRs in achieving conservation objectives as measured by fish abundance and species richness. I found that community composition significantly differed between NRs and ARs. ARs had high variability in rockfish abundance, while NRs consistently supported intermediate rockfish abundances. Groundfish diversity was markedly greater on NRs. Depth and relief significantly explained variability in abundance and species richness. Interestingly, rockfish abundance was negatively associated with proximity to nearest rockfish conservation area. In my third chapter, I assess variation between AR fish communities on six reefs to better understand efficacy of meeting conservation objectives. I quantified structural characteristics of each reef using high-definition sonar data to create three-dimensional models and calculate measurements of reef structure. I also examined the effects of surrounding habitat associated with reef locations. I found that depth, conservation status, rugosity, and reef age significantly explained rockfish abundance. Groundfish species richness was significantly associated with conservation status, relief, reef size, and an interaction between depth and reef age. This research is a first step in proposing underlying mechanisms for differences between fish communities on ARs in BC, and which reef attributes facilitate successful contributions to conservation. Though ARs show promise in the conservation of some threatened species, the maintenance of diverse fish communities may depend on protection of heterogeneous natural reef communities. Given that a critical component of AR success is structure, using three-dimensional technologies can be used as a tool to understand species-habitat association on existing reefs and help predict the success of future reefs. en_US
dc.language English eng
dc.language.iso en en_US
dc.rights Available to the World Wide Web en_US
dc.subject Artificial Reef en_US
dc.subject Rockfish en_US
dc.subject Conservation en_US
dc.subject Fish Habitat en_US
dc.subject ROV en_US
dc.subject Temperate Reef en_US
dc.subject Sonar en_US
dc.subject 3D-modelling en_US
dc.title Evaluating British Columbia’s artificial reefs in a conservation context en_US
dc.type Thesis en_US
dc.contributor.supervisor Volpe, John
dc.degree.department School of Environmental Studies en_US
dc.degree.level Master of Science M.Sc. en_US
dc.description.scholarlevel Graduate en_US

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