The ecology of marine tidal race environments and the impact of tidal energy development
Author(s)
Broadhurst, Melanie
Type
Thesis
Abstract
Marine tidal race environments undergo extreme hydrodynamic regimes and are favoured
locations for offshore marine renewable tidal energy developments. Few ecological studies
have been conducted within these complex environments, and therefore, ecological impacts
from tidal energy developments remain unknown. This thesis aimed to investigate the
ecological aspects of marine tidal race environments in two themes, using a combination of
field-based sampling techniques.
I first examined the natural ecological variation of a marine tidal race environment at the
spatial and temporal scale. These studies were based on the benthic and intertidal
communities within the Alderney Race tidal environment, Alderney. My results suggest that
both communities vary in species diversity and composition, at different spatial gradients and
timescales. Species showed opportunistic or resilient life history characteristics, highlighting
the overall influence of the strong hydrodynamic conditions present.
I then explored the ecology of a marine tidal race environment within a renewable tidal
energy development site. These studies were based within the European Marine Energy
Centre’s tidal energy development site, Orkney. Here, I investigated ecological variation in
terms of fish interaction and benthic assemblage structure with a deployed tidal energy
device, and, the structure of intertidal communities within the overall development site.
Interestingly, my results indicated species-specific interactions with the deployed tidal energy
device, which was related to species’ refuge or feeding behaviour. These results also imply
that different communities show varied spatial and temporal heterogeneity within a
development site, associated with the complex interplay of abiotic and biotic processes.
This work begins to reveal the ecological consequences of tidal energy development, with
single devices acting as potential short-term artificial reef structures. Further research is
recommended within these environments, with reference to how the hydrodynamic regimes
directly influence these communities, and, the overall ecological consequences of future
large-scale tidal energy development scenarios.
locations for offshore marine renewable tidal energy developments. Few ecological studies
have been conducted within these complex environments, and therefore, ecological impacts
from tidal energy developments remain unknown. This thesis aimed to investigate the
ecological aspects of marine tidal race environments in two themes, using a combination of
field-based sampling techniques.
I first examined the natural ecological variation of a marine tidal race environment at the
spatial and temporal scale. These studies were based on the benthic and intertidal
communities within the Alderney Race tidal environment, Alderney. My results suggest that
both communities vary in species diversity and composition, at different spatial gradients and
timescales. Species showed opportunistic or resilient life history characteristics, highlighting
the overall influence of the strong hydrodynamic conditions present.
I then explored the ecology of a marine tidal race environment within a renewable tidal
energy development site. These studies were based within the European Marine Energy
Centre’s tidal energy development site, Orkney. Here, I investigated ecological variation in
terms of fish interaction and benthic assemblage structure with a deployed tidal energy
device, and, the structure of intertidal communities within the overall development site.
Interestingly, my results indicated species-specific interactions with the deployed tidal energy
device, which was related to species’ refuge or feeding behaviour. These results also imply
that different communities show varied spatial and temporal heterogeneity within a
development site, associated with the complex interplay of abiotic and biotic processes.
This work begins to reveal the ecological consequences of tidal energy development, with
single devices acting as potential short-term artificial reef structures. Further research is
recommended within these environments, with reference to how the hydrodynamic regimes
directly influence these communities, and, the overall ecological consequences of future
large-scale tidal energy development scenarios.
Date Issued
2012-10
Date Awarded
2013-07
Advisor
Power, Sally
Agnew, David
Sponsor
Biotechnology and Biological Sciences Research Council (Great Britain) ; Alderney Renewable Energy Ltd (Great Britain)
Publisher Department
Division of Ecology and Evolution
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)