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Coral Bioerosion at Enewetak: Agents and Dynamics
Author(s) -
Highsmith Raymond C.
Publication year - 1981
Publication title -
internationale revue der gesamten hydrobiologie und hydrographie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.524
H-Index - 52
eISSN - 1522-2632
pISSN - 0020-9309
DOI - 10.1002/iroh.19810660307
Subject(s) - coral , bioerosion , porites , cnidaria , breakage , biology , rubble , anthozoa , barnacle , ecology , geology , crustacean , geotechnical engineering , materials science , composite material
Significant differences were found in the extent to which massive coral species at Enewetak are excavated by boring organisms: Goniastrea retiformis , 7.9%; Porites lutea , 2.5%; and Favia pallida , 1.2%. While polychaetes constituted the most abundant and diverse group of coral associates, clionid sponges accounted for approximately 70–80% of skeletal damage. Clionid boring rates are initially very high but burrowing ceases when a particular burrow size (˜0.6 cm) or distance from the surface (≦2 cm) is reached. Most coral skeletal excavation occurs within 2 cm of a dead surface. Therefore, bioerosional damage to corals depends primarily on the amount of skeletal surface not covered by live coral tissue. Damage to skeletons is inversely correlated with colony size but is not correlated with coral growth rates or water depth. Massive corals have a potential escape in size from catastrophic bioerosion. Models relating 1) coral growth forms to skeletal density and stability in currents, 2) resistance of coral skeletons to breakage by water movement and suspended rubble, and 3) dead surface area on coral heads to bioerosional damage and consequent probability of detachment from the substrate, are proposed.