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 />
The greatest risk associated with fishing-cable interactions is to trawlers that<br />
may ‘snag’ a cable, which can pose a significant danger to the vessel <strong>and</strong> its<br />
crew, if not properly managed. Guidance for the fishing industry regarding<br />
submarine cables is presented in “Fishing <strong>and</strong> Submarine Cables Working<br />
Together” produced by the International Cable Protection Committee (ICPC)<br />
(Drew & Hopper, 1996) <strong>and</strong> free charts which ICPC issue to fishermen to plot<br />
the routes <strong>of</strong> submarine cables. This information is intended to help fishermen<br />
avoid snagging submarine cables <strong>and</strong> to provide information about what to do<br />
if a cable becomes caught in fishing gear.<br />
5.5.1 POTENTIAL EFFECTS<br />
Access to fishing grounds<br />
Fishing vessels are prevented from fishing within the immediate area during<br />
cable laying <strong>and</strong> burial operations. As a result there may be short term restrictions<br />
to fishing grounds. In some areas, fishing vessels affected will be temporarily<br />
displaced to adjacent fishing grounds, which can lead to an increased risk <strong>of</strong><br />
gear conflict <strong>and</strong> a temporary reduction in catches where fishermen are forced<br />
to fish unfamiliar or less favourable grounds.<br />
During cable installation operations a safety zone surrounding work boats<br />
should be established; this can result in increased steaming times to fishing<br />
grounds <strong>and</strong> hence increased fuel costs <strong>and</strong> reduced fishing time or a longer<br />
working day. Again this is a short-term impact that may be difficult to quantify<br />
as fishing vessels will <strong>of</strong>ten target several fishing grounds <strong>and</strong> so should be able<br />
to fish alternative grounds to avoid short-term restrictions. The l<strong>and</strong>ing <strong>of</strong> the<br />
cable in constricted areas (e.g. narrow estuaries) can interfere more significantly<br />
with fishing vessel movements as vessels may be restricted in departing from<br />
or returning to port/berths.<br />
As restrictions are likely to be short term, impacts are generally thought to be<br />
minimal. For example, the two export cables from the North Hoyle wind farm<br />
to the l<strong>and</strong>ing beach, a distance <strong>of</strong> 7.5 km, took approximately 4 to 5 days each<br />
to lay <strong>and</strong> bury (Bomel Ltd., pers. comm.). Furthermore, one <strong>of</strong> the l<strong>and</strong>ing<br />
routes under consideration for the North Hoyle project up the Rhyl estuary was<br />
ab<strong>and</strong>oned in favour <strong>of</strong> alternative route, partly because <strong>of</strong> the disruption this<br />
would have caused to the local fishing fleet (Bomel Ltd., pers. comm.). Therefore,<br />
the likely impact on access to commercial fishing grounds is likely to be small<br />
given the wider impacts <strong>of</strong> the wind farm.<br />
Fish stock displacement<br />
During construction there will be a short term movement <strong>of</strong> fish away from the<br />
cable laying area due to inter alia noise, seabed habitat alteration <strong>and</strong> turbidity<br />
(see Section 5.4).<br />
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