Editing Submarine communications cable (section)

=== Pollution ===

Submarine cables are made of copper or [[optical fiber]]s, surrounded by several protective layers of plastic, wire or synthetic materials. Cables can also be composed of dielectric fluids or [[hydrocarbon]] fluids, which act as electrical insulators. These substances can be harmful to marine life.<ref>{{Cite book |last=Worzyk |first=Thomas |url=https://books.google.com/books?id=X8QfRT_SYDgC&dq=environmental+impact+of+submarines+cables&pg=PR6 |title=Submarine Power Cables: Design, Installation, Repair, Environmental Aspects |date=2009-08-11 |publisher=Springer Science & Business Media |isbn=978-3-642-01270-9 |language=en}}</ref>

Fishing, aging cables and marine species that collide with or become entangled in cables can damage cables and spread toxic and harmful substances into the sea. However, the impact of submarine cables is limited compared with other sources of ocean pollution.

There is also a risk of releasing pollutants buried in sediments. When sediments are re-suspended due to the installation of cables, toxic substances such as hydrocarbons may be released.

Preliminary analyses can assess the level of sediment toxicity and select a cable route that avoids the remobilization and dispersion of sediment pollutants. And new, more modern techniques will make it possible to use less polluting materials for cable construction.<ref name=":10" />