Mortality of the Bryozoan Pentapora fascialis in the Ligurian Sea (NW Mediterranean) after Disturbance
Pentapora fascialis (Pallas) population at Tino Island (Ligurian Sea, NW Mediterranean) underwent total and partial mortality. A severe sea-storm occurred in December 1993, caused near total mortality of the colonies at the shallow station (11 m depth): seven out of eight colonies were swept away. Total mortality was not size-selective and was independent of density. The deeper station (22 m depth) resulted unaffected by the sea-storm. Partial mortality, i.e. necrosis and loss of portions of colony, affected exclusively the largest colonies subjected to long lasting epibiosis and high sedimentation. Changes in the morphological characters (large cross-sectional area and poor adhesion to the substratum), wich occurred in the largest colonies, enhanced their susceptibility to dislodgement.
KeywordsGreat Barrier Reef Large Coloni Deep Station Shallow Station Partial Mortality
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