Review of Cabling Techniques and Environmental Effects Applicable
Review of Cabling Techniques and Environmental Effects Applicable
Review of Cabling Techniques and Environmental Effects Applicable
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<strong>Review</strong> <strong>of</strong> <strong>Cabling</strong> <strong>Techniques</strong> <strong>and</strong> <strong>Environmental</strong> <strong>Effects</strong> <strong>Applicable</strong> to the Offshore Wind<br />
Farm Industry – Technical Report<br />
level. The main potential impact is the disruption <strong>of</strong> the sensory cues for feeding<br />
in benthic dwellers in <strong>and</strong> around the wind farm area. This is general for all<br />
species <strong>of</strong> benthic dwelling elasmobranchii that feed diurnally <strong>and</strong> nocturnally.<br />
EMF could have two possible effects on the behaviour <strong>of</strong> elasmobranchii. Firstly,<br />
resident elasmobranchii could be deterred from feeding in <strong>and</strong> around the area<br />
within the wind farm footprint <strong>and</strong> where cables are buried. The second impact<br />
could be one <strong>of</strong> attraction <strong>of</strong> elasmobranchii to the footprint <strong>of</strong> the wind farm<br />
potentially causing an unnatural clustering effect in the area.<br />
There are, therefore, potentially significant effects on fisheries interests but to<br />
date there has been no evidence to indicate the likelihood <strong>and</strong>/or magnitude <strong>of</strong><br />
these. The research undertaken by COWRIE, under laboratory conditions only has<br />
been insufficient to determine the precise extent <strong>of</strong> detection for many marine<br />
species; the behavioural response within the zone <strong>of</strong> detection <strong>and</strong> therefore the<br />
likely impacts on fisheries resources due to EMF from sub-sea cables (COWRIE<br />
2005).<br />
For the Thanet Offshore Wind Farm site, English Nature stated that (given current<br />
levels <strong>of</strong> ecological underst<strong>and</strong>ing) there will not be a significant impact to the<br />
populations <strong>of</strong> elasmobranchii that are resident within the wind farm footprint<br />
<strong>and</strong> cable export route but English Nature’s advice is provided in the light <strong>of</strong><br />
current information that is available (English Nature, 2006).<br />
Additional research work on electromagnetic field effects is due to be carried out<br />
under the auspices <strong>of</strong> COWRIE, which will entail “in the field” research. It is likely<br />
therefore that developers will be asked to commit to take on board the most up<br />
to date information on electromagnetic field effects, thereby making necessary<br />
<strong>and</strong> reasonable adaptations during the construction, operation <strong>and</strong> monitoring<br />
<strong>of</strong> wind farm developments.<br />
5.4.2 MITIGATION MEASURES<br />
In terms <strong>of</strong> the natural fish resource, general mitigation measures should seek<br />
to do the following:<br />
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Avoid spawning <strong>and</strong> nursery habitats. Such information should be available<br />
from published sources or previous surveys. If this is not available then a<br />
series <strong>of</strong> dedicated surveys should be commissioned as part <strong>of</strong> the wider EIA,<br />
in discussions with Cefas;<br />
Avoid sensitive spawning times for substrate spawning species where<br />
possible (exact periods will be site specific <strong>and</strong> require evidence);<br />
Impacts from noise may be mitigated by timing construction to avoid sensitive<br />
feeding, spawning <strong>and</strong> nursery area/times <strong>of</strong> the year;