a type of marine protected area, fully protected from all extractive and potentially damaging activities, such as fishing, dredging, aquaculture and mining. Often described as ‘no-take zones’.

predators that have no predators of their own, residing at the top of their food chain. Apex predators occupy the highest trophic level and have a crucial role in maintaining the health of their ecosystems.

a chain or cluster of islands, sometimes called an island group.

the benthic zone is the lowest level of a body of water in the ocean and includes the seabed. Benthic species are those that live on or in close proximity to the seabed.

a measure of the variety of life forms within a given habitat or ecosystem. Biodiversity is used as a measure of ecosystem health, with healthier ecosystems being more diverse.

a measure of the biological material in a given habitat or species, often expressed as the weight of organisms per unit area.

the extended perimeter of each continent that is submerged under the sea.

­– self-governing possessions of the British Crown. They are; the Isle of Man and the Channel Islands (Bailiwick of Jersey, Bailiwick of Guernsey). None form part of the UK or the European Union.