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Cables
Numerous telecommunications cables run across the
bed of the Irish Sea. There is some evidence that
sharks and rays are attracted to unshielded electromagnetic
fields.
Commercial
Shipping
Whilst vital to the economy, commercial shipping has
the potential to impact on marine ecosystems directly
through collision with larger marine animals and indirectly
through chemical or noise pollution and the dumping
of litter at sea. Commercial passenger shipping may
be many people's only contact with the open sea.
See
also:
'Watching
The Ships Go By" - live vessel movements from around
the Irish Sea - http://www.aisliverpool.org.uk'.
Effluent
Since the industrial revolution in the 19th century
the Irish Sea has been used as a convenient site for
disposal of liquid waste, including sewage and unwanted
by-products of industrial processes such as mining,
manufacturing, nuclear waste reprocessing and energy
generation.
The
treatment of sewage and industrial waste discharged
into watercourses and directly into the sea has improved
steadily since the latter half of the 20th century.
Sewage and other waste is no longer dumped offshore.
However, the legacy of past practices still remains,
particularly in the case of 'heavy metal' pollution
by compounds of lead, cadmium, arsenic and other poisons,
which bind into sediment on the seabed.
The
levels of agricultural effluent flowing off fields
into rivers and thence the sea has increased markedly
over the same period, leading to increased fertility
of inshore waters and associated algal blooms and
de-oxygenation of seawater, particularly in enclosed
bays and estuaries.
Products
in every day use in our homes may contain a wide variety
of inorganic chemicals and organic compounds. These
are also flushed or washed away after bathing or showering,
or disposed of directly into the drains.
These
substances discharged into the sea may combine together
in ways that make it difficult to predict their ultimate
effect of the marine environment. Some may remain
indefinitely in the seawater, the seabed, or the flesh,
fat and oil of sea creatures.
See
also:
WWF-UK: http://www.wwf.org.uk/filelibrary/pdf/ma_waste_wa.pdf
Irish Sea Forum: http://www.liv.ac.uk/~isf1/semsums/sem10sum.html
Surfers Against Sewage http://sas.org.uk
Fisheries
Commercial fisheries may damage the marine ecosystem
directly, through competition and increased efficiency
leading to unsustainable demands on target species,
or indirectly through by-catch and the impact of fishing
methods on the seabed. The activities of different
fishing sectors may also impact on one another's success.
The
Marine Conservation Society has published 'The Good
Fish Guide', giving advice on choosing 'environmentally
friendly' fish to eat. You can order a copy at www.mcsuk.org.
Land Reclamation & Coastal Defences
Most of the estuaries of the Irish Sea have shrunk as
a result of the damming and drainage of the seashore
and seabed to create farmland and building land. This
leads to an indefinite requirement on society or the
individual landowners to maintain these sea defences,
and to 'coastal
squeeze' as sea levels rise.
Marine
Aggregate Extraction
Currently, sand and gravel taken from the sea make
up 21% of the supply in England and Wales (no figures
found for other countries around the Irish Sea). These
materials - known as marine aggregate - are used by
the construction industry (e.g. in concrete) and for
replenishing beaches that have eroded away.
Marine
aggregate extraction inevitably has drastic short-term
effects on marine wildlife and habitats in the area
directly affected, and we are only beginning to understand
the process of recovery. The Wildlife Trusts are working
with the British
Marine Aggregate Producers' Association to develop
a better understanding of the industry and its impacts.
At
present, the conservation of offshore sand and gravel
biotopes in the Irish Sea is wholly reliant on the
environmental management of marine aggregate extraction
and other industries, as neither the Habitats Directive
nor Biodiversity Action Planning have been actively
applied in this environment. Marine Spatial Planning
is a developing tool that might be applied to ensure
more effective, integrated management and protection
of marine biotopes.
Marine Turbines
An underwater marine turbine is to be tested in The
Narrows at Strangford Lough, Co. Down by Marine
Current Turbines Ltd.
Navigational Dredging
The approaches to the ports of Ardrossan, Belfast, Douglas,
Larne, Dublin/Dun Laoghaire, Fleetwood, Glasgow, Heysham,
Liverpool, Milford Haven/Pembroke, Rosslare, Stranraer/Cairnryan,
Troon and Warrenpoint/Carlingford must be regularly
dredged to maintain access for large vessels.
Offshore Wind Turbines
There are proposals for construction of wind turbine
arrays ('wind farms') in the Solway Firth, off Morecambe
Bay, off the Fylde Peninsula, in Liverpool Bay and off
the coast of Co. Wexford. A 'wind farm' has already
been constructed off the coast of Flintshire.
Oil & Gas Extraction
BHP
Billiton extracts oil and natural gas from the Douglas
and Hamilton fields in Liverpool Bay. Centrica
extracts natural gas from several fields off Morecambe
Bay and the Fylde Peninsula.
Pipeline Construction & Maintenance
Numerous active and redundant oil and gas pipelines
run across the bed of the Irish Sea.
Tidal Barrages
There are currently outline discussion proposals for
tidal barrages across the Ribble Estuary, Morecambe
Bay and the Mersey Estuary, though no formal planning
applications have been submitted.
Water-based
Recreation
Increasing leisure time can lead to increased contact
with and understanding marine wildlife. However, construction
of marinas and an increase in marine traffic, particularly
motorised vessels, has the potential to increase pressure
on marine wildlife. This can be through direct contact
- as is the case with dolphins, porpoises, seals and
basking sharks, or indirectly through increased marine
pollution and litter or loss of foreshore to "hard"
development.
The
Green Blue is a new environmental awareness
initiative by the British Marine Federation and the
Royal Yachting Association. It hopes to educate and
inform the recreational boating community about its
environmental impacts, emphasising how industry and
users can avoid or minimise these impacts. |

Runcorn Docks, Mersey Estuary
Cheshire
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