Coasts and Oceans : Glossary

There are 30 documents in this section.

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  • Trawling

    13 October 2000

    A fishing technique whereby fishing vessels drag a huge sock-like net through the water, capturing many different kinds of organisms in the process. One form, bottom trawling, drags a huge net along the bottom of the sea. It acts almost like a plough, pulling in many fish, shellfish and other organisms and destroying bottom habitats.

  • Mangrove forests

    13 October 2000

    Some 80 species of mangrove trees - trees on stilts, as they have been described - are found in a wide belt around the earth in tropical and semi-tropical climates. They are biologically rich ecosystems, harbouring some 2,000 species of plants and animals.

  • Littoral

    13 October 2000

    Have a sea coast. The coast itself

  • TEDs

    13 October 2000

    Turtle Excluding Devices; these are supposed to be fitted to trawl nets in an effort to reduce the by-catch of turtles and other vulnerable marine creatures.

  • Eutrophication

    22 August 2000

    The occurrence of high nutrient levels in freshwater and marine ecosystems, usually resulting in excessive plant growth and the death of animal and some plant life due to oxygen deprivation.

  • Global warming

    22 August 2000

    The idea that increased greenhouse gases cause the Earth's temperature to rise globally.

  • CFC's (Chlorofluorocarbons)

    21 August 2000

    A group of chemicals containing chlorine (Cl), fluorine (F) and carbon (C), sometimes referred to by their trade name Freon. These synthetic compounds were used extensively for refrigeration and aerosol sprays until it was realized that they destroy ozone (they are also very powerful greenhouse gases) and have a very long lifetime once in the atmosphere (more than 100 years). The Montreal Protocol agreement of 1987 has resulted in the scaling down of CFC production and use in industrialised countries.

  • Ecological balance

    21 August 2000

    Stability in an ecosystem achieved through the development of equilibrium among its various components. This does not imply that the community is static. It is subject to natural variations associated with ecological succession and other influences such as fire, disease and climate change, but the system is normally sufficiently elastic to make the necessary adjustments without major displacement of the balance. Human intervention that includes the introduction or removal of plants and animals, pollution of the environment and destruction of habitat is now a main cause of imbalance in many ecosystems.

  • El Niño/Southern Oscillation (ENSO)

    21 August 2000

    El Niño is the name originally given by local inhabitants to a weak warm ocean current flowing along the coast of Ecuador and Peru. ENSO is an extensive, intense, atmospheric and oceanic phenomenon affecting the tropical Pacific Ocean. It is associated with major anomalies in atmospheric circulation and rainfall patterns. El Niño occurs irregularly, but approximately every four years on average. ENSO events have impacts on fisheries, bird life and mainland weather.

  • Biodiversity

    12 August 2000

    The term biological diversity, or biodiversity, refers collectively to the full range of species, genes and ecosystems in a given place.

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