Review of Cabling Techniques and Environmental Effects Applicable

5 Potential impacts and
mitigation measures
5.1 Introduction
This section addresses the potential environmental impacts that could be
experienced during cable installation activities, together with possible mitigation
measures that can be used to minimise the magnitude and significance of
effects. Although the length of the corridor for cable installation impacts can be
long, the footprint of impact is narrow, generally restricted to 2-3m width, with
certain methods of installation requiring the use of anchors (see Section 3.9.1).
The main impact associated with cable installation relates to the disturbance of
sediment (Section 4.3) and the subsequent creation of a sediment plume. The
disturbance is restricted to the area described above and the generation of a
plume and subsequent settlement is localised, with the area affected dependent
on geological and hydrodynamic characteristics. Although the scale of effect will
be site specific it is important that the impact should be put into context with
natural perturbations resulting from storm activity and other activities occurring
in the vicinity including fisheries, aggregate extraction, and other sediment
plume generating activities.
Impacts and mitigation measures are described and discussed for:
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Subtidal ecology;
Intertidal habitats;
Natural fish resource;
Fisheries;
Marine mammals;
Ornithology;
Shipping and navigation;
Seascape and visual character; and
Marine and coastal archaeology.
Discussion of impacts is divided into two categories:
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Potentially significant impacts – which are considered relevant to the
installation of cables and could result in significant environmental effects;
and where relevant
Other impacts – which may be considered to be impacts by stakeholders but,
are unlikely to cause significant effects.
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