Factors capable of modifying the ambient water temperature of seagrass
meadows may include: global temperature oscillations
(e.g. El Nifio), global warming, seasonal and diurnal
fluctuations, and heated effluent water from electricity
generation and industrial processing plants (Edwards
1995). Seagrass ecology is strongly influenced by thermal
conditions; this is well documented where cooling
waste-water discharge into estuaries and lakes can
increase the ambient water temperature by up to 10°
(Thorhaug et al. 1978, King & Holland 1986, Marshman
& Hodgson 1991). Heated effluent water has also
been found to alter the local distribution of seagrass
species, and to reduce the vigour of the surviving
meadows (King & Holland 1986).