| Autor: |
John Wellington, Barrie Entsch, Robin G. Sim, Kevin Boto |
| Rok vydání: |
1983 |
| Předmět: |
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| Zdroj: |
Limnology and Oceanography. 28:465-476 |
| ISSN: |
0024-3590 |
| DOI: |
10.4319/lo.1983.28.3.0465 |
| Popis: |
The occurrence of P and N in the sediments has been investigated on Davies Reef in the central region of the Great Barrier Reef Complex. Concentrations of inorganic P and N in the water were typical of nutrient-depleted tropical surface water. Carbonate sediments were found to contain a uniform pool of P (300 ppm by wt), principally in the form of inorganic phosphate. The interstitial water of the surface layer of sediment contained micromolar concentrations of inorganic P and even higher concentrations of inorganic N, principally as ammonium. These nutrient concentrations should allow high rates of uptake of N and P by epilithic algae. Arsenate concentrations were considered too low to compete significantly with the uptake of available phosphate into algae. The presence of ammonium and soluble P was associated with anaerobic redox potentials in the sediments just below the surface. Soluble phosphorus was in equilibrium with a small, rapidly exchangeable fraction of the sedimentary pool of inorganic phosphate. Analyses of P in growing tips of Halimeda and corals (which supply more than half of reef sediments) suggested that the skeletons provide a biological mechanism for the replenishment of at least some of the sedimentary pool. Ratios of C:N:P for a selection of benthic algae were used as a preliminary indicator of their N and P status. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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