Article publication date: 2014-09-01
Vol. 32 No. 2/3 (yearly), pp. 93-101.
Phosphorus, Marine, Coastal, Sediment, Red Sea, Speciation.
The total phosphorus concentrations and its speciation were studied in the surface sediment of Khawr ash Shaibah al Maftuhah. The distribution pattern of total phosphorus in the sediment showed east-west gradient indicating different depositional environment of the lagoon. The largest pool of the sedimentary phosphorus was apatitic phosphorus (57%) followed by refractory organic phosphorus (42%). The impact of loosely adsorbed and exchangeable phosphorus (0.9 % of total phosphorus) and Metal oxide Phosphorus (0.6 % of total phosphorus) on the budget of total phosphorus in the sediments was minor. The concentration of dissolved phosphorus in the upper water column is most probably buffered by apatitic phosphorus. The low concentration of metal oxide phosphorus is suggested to be influenced by the calcareous nature of the lagoon. Possible transformation between apatitic and refractory organic phosphorus is inferred from the correlation of both parameters. The correlation of refractory organic carbon with total phosphorus in the sediments suggests in situ production due to biological activities.