Recovery of corals from sublethal stress

Recovery of corals from sublethal stress RG7422 cell line can be rapid (weeks to months), while recovery from partial mortality takes several years. Reef recovery from mass mortality is generally slow and may take many years to decades, while in some cases recovery has not occurred at all. Few examples of recovery of coral reefs after severe sediment damage have been documented. Increased sedimentation is sometimes accompanied by other stresses, prolonging or inhibiting recovery,

making it difficult to generalise or make predictions about recovery (Rogers, 1990). Of 65 examples for which sufficient data exist to make a judgment, coral cover recovered in 69% of cases after acute, short-term disturbances, but only in 27% of cases after chronic, long-term disturbance (Connell, 1997). Wesseling et al. (1999) noted that the recovery time of corals following experimental short-term burial varied among

coral species, ranging from several weeks to months, and also depended on the duration of the sedimentation event. In larger massive corals, sediment burial may cause bleaching and damaged patches, which—if larger than about 2 cm in diameter—do not recover, but will be colonised by algae or sponges preventing recovery of the coral (Hodgson, 1994). Brown Atezolizumab et al. (1990) reported a 30% reduction in living coral cover 1 year after the start of dredging operations at Phuket (Thailand). After the dredging event had ceased, the reef recovered rapidly with coral cover values and diversity indices restored to former levels around 22 months after dredging began. The domination of this reef by massive coral species, which are physiologically adapted to intertidal living and which display partial rather than total colony mortality, may have contributed to its apparent resilience (Brown et al., 2002). Maragos (1972) estimated that 80% of the coral communities in the lagoon of Kaneohe Bay (Hawaii) died because of a combination of dredging, increased sedimentation and sewage discharge. Six years after discharge of sewage into Kaneohe Bay ceased, a dramatic

recovery of corals and a decrease in the growth of smothering algae was reported (Maragos et Carbohydrate al., 1985). Coastal coral reefs adjacent to population centers often do not recover from disturbances, in contrast to remote reefs in relatively pristine environments, because chronic human influences have degraded water and substratum quality, thereby inhibiting recovery (McCook, 1999a and Wolanski et al., 2004). In the Seychelles, where corals had to recover from an intense bleaching event, Acropora species—usually the first to rapidly colonise new empty spaces—recovered substantially more slowly due to recruitment limitation, because these species were virtually eliminated throughout almost the entire Indian Ocean ( Goreau, 1998).

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