Status
Principle Investigator Contact Information
Name: Melanie Broadhurst
Address: Munro Building 2.1, Division of Ecology and Evolution
Phone: +447781-453976
Description
To determine the ecological impacts from a deployed tidal energy test device, within the pelagic, benthic and intertidal regions of the marine environment. The project entails conducting a number of field-based studies to examine ecological impacts in terms of; species’ abundance, biodiversity, composition and functional form across the spatial and temporal scale. Studies include:
- Fish species response using video sampling and ADCP methods.
- Benthic species assemblage and habitat responses, using commercial potting and towed video techniques.
- Intertidal macroalgae and faunal species assemblage responses, using shoreline transect-based methods.
Funding Source
BBSRC Industrial Case PhD studentship
Location of Research
Orkney Isles, Scotland
Project Aims
To determine the ecological impacts from a deployed tidal energy test device, within the pelagic, benthic and intertidal regions of the marine environment. The project involved a number of field-based studies to examine ecological impacts in terms of; species’ abundance, biodiversity, composition and functional form across the spatial and temporal scale. Studies include:
- Fish species response using video sampling and ADCP methods.
- Benthic species assemblage and habitat responses, using commercial potting and towed video techniques.
- Intertidal macroalgae and faunal species assemblage responses, using shoreline transect-based methods.
Study Progress
Project has been completed.
Key Findings
Fish Assessment:
- From the video surveys, fish (specifically Pollachius pollachius) were observed aggregating surrounding the deployed device, suggesting devices act as temporary artificial reef structures.
- The size and presence of these aggregations significantly altered across the measured hour, day and year temporal scales (compared using generalized linear models).
- Fish abundance was correlated to tidal velocity flow (measured by ADCP), with increased velocity reducing fish observations.
Benthic Assemblage Assessment:
- Benthic species diversity, composition and functional form differed between the benthic regions of the deployed device and a chosen control site (compared using generalised linear models and multivariate analyses). These results also outline the potential for deployed devices to act as potential artificial reefs for certain benthic species i.e. Homarus gammarus.
- Overall, species composition and functional form were related to the type of present exposed benthic environment which undergo strong hydrodynamic regimes.
- Species diversity and composition estimates altered over the short-term measured seasonal scales, potentially related to known natural environmental and biological processes i.e. recruitment, reproduction.
- Benthic habitats showed similar compositions between the benthic location of the device and control site (compared using multivariate analyses and basic descriptive techniques). This research suggests the level of impact differs at the chosen sampling method and scale of study (species vs habitat) and therefore warrants further investigation.
Intertidal Assemblage Assessment:
- Macroalgae species biodiversity, composition and functional form differed between the shorelines located adjacent to the deployed device and shorelines within the control site (using generalised linear models and multivariate analyses).
- The device shorelines comprised of additional species which are representative indicator species of coastal development. This could be attributed to the activities associated with tidal energy test site i.e. increased vessel use, deployed structures etc.
- Faunal species biodiversity, composition and functional form showed weak differences between the device and control shorelines. This was due to both shorelines dominated by a small number of faunal species.
- Both macroalgae and faunal species diversity and compositions showed weak differences across the measured seasonal temporal scales.
- Overall, species life history traits and functional form within both shorelines were related to the type of environment present i.e. highly exposed, rocky-shoreline habitats.
- This project also suggests the scale of ecological impact is dependent upon the selected ecological receptor and measured scales for study.