The prediction and assessment of the environmental impacts of the Loch Linnhe Artificial Reef

Research output: ThesisDoctoral Thesis (not awarded by UHI)

Abstract

Artificial reefs are deliberately or accidentally deployed structures, lying on the sea- or lakebed that increase localised habitat complexity. The construction of artificial reefs, within Europe, is licensed through the Food and Environment Protection Act (FEPA) (1985) (as amended by the Environmental Protection Act (1990)), which includes a requirement for the monitoring of the impacts of the licensed structure. The Loch Linnhe Artificial Reef was the first experimental artificial reef to be licensed in the UK and the first such application to be processed under the devolved Scottish parliament.
Artificial reefs can impact the environment in a number of ways including through the leaching of reef components and, through interaction with water currents, sedimentary change. The concrete blocks used in the construction of the Loch Linnhe Artificial Reef consist of granitic by-products consolidated using a blend of cement and fly-ash. The blocks were shown to leach significantly greater quantities of iron, molybdenum, rubidium and strontium compared with either granite or the control. However, the leachate concentrations were so low as not to pose a threat to the environment.
Reef induced current changes may result in localised changes in sediment granulometry around the reef. The acoustic ground discrimination system RoxAnn™ was assessed to determine if it could be used to monitor such large-scale sedimentary changes. RoxAnn™ suffered large and inexplicable variations in its interpretation of the sea bed and was therefore not suitable for such a role.
Hydrological changes occurring around the edges of two reef units resulted in the deposition of macrophytic detritus at the reef edge, material that subsequently decayed. Whilst no granulometric changes in the sediment were observed at the reef edge significant changes in the benthic community were observed and linked to low levels of sedimentary oxygenation.
Original languageEnglish
Publication statusPublished - 1 Sep 2003

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