High rates of nitrogen fixation on coral skeletons after predation by the crown of thorns starfishAcanthaster planci
✍ Scribed by A. W. D. Larkum
- Publisher
- Springer-Verlag
- Year
- 1988
- Tongue
- English
- Weight
- 358 KB
- Volume
- 97
- Category
- Article
- ISSN
- 0025-3162
No coin nor oath required. For personal study only.
✦ Synopsis
At One Tree Reef, Great Barrier Reef, Australia, between 1983 and1985, corals killed by the crown of thorns seastar Acanthaster planci L. gave rise to skeletons which were colonised rapidly by blue-green and other algae. For the next 3 to 9 mo these coral skeletons showed over three times more nitrogen fixation (acetylene reduction) than control substratum rates (9 to 32 nmol vs 3 to 10nmol C2H2 cm -2 h -1, over all seasons). These values convert to relatively high annual fixation rates of 37 to 127 kg N ha --1 yr -~ but, at the low densities ofA. planci on One Tree Reef (ca. 0.65 ha-~), this has little impact on the total nitrogen fixation rate and, as a result, on the level of organic nitrogen in the system. However, it is suggested that on reefs subjected to high aggregations of A. planci such an effect would enhance the level of organic nitrogen and lead to greater primary and secondary production throughout the reef system.