Content of Organic Carbon,Nitrogen, and Phosphorus in Deep-Water Coralline Algae Biocenoses,South China Sea

Oceanology - The influence of habitat depth on the content of organic carbon (Corg), as well as organic and mineral forms of nitrogen (N) and phosphorus (P), in the biocenosis of coralline algae at...     

Influence of the environmental factors on the intensity of the oxygen,ammonium, and phosphate metabolism in the agar-containing seaweed <Emphasis Type="Italic">Ahnfeltia tobuchiensis</Emphasis> (Ahnfeltiales,Rhodophyta)

A complex study of the influence of various environmental factors on the rate of the oxygen (M_{O 2}), ammonium (M_{NH 4}), and phosphate (M_{PO 4}) metabolism in Ahnfeltia tobuchiensis has been carried out in situ in the Izmena Bay of Kunashir Island. The following environmental factors have been included into the investigation: the photosynthetically active radiation (PAR); the ammonium (NH₄); the phosphate (PO₄); and the tissue content of carbon (C), nitrogen (N), phosphorus (P), and chlorophyll a (Chl). The population of agar-containing seaweed A. tobuchiensis forms a layer with a thickness up to 0.5 m, which occupies about 23.3 km²; the population’s biomass is equal to 125000 tons. The quantitative assessment of the organic matter production and nutrient consumption during the oxygen metabolism (M_{O 2}) has been carried out for the whole population. It has been shown that the daily rate depends on the PAR intensity, the seawater concentrations of PO₄ and NH₄, and the tissue content of N and P (r ² = 0.78, p < 0.001). The daily NH₄ consumption averages 0.21 μmol/(g_DW h) and depends on the NH₄ and O₂ concentrations in the seawater and on the C and Chl a content in the algal tissues (r ² = 0.64, p < 0.001). The daily PO₄ consumption averages 0.01 μmol/(g_DW h) and depends on the NH₄ concentration in the seawater and on the P content in the algal tissues (r ² = 0.40, p < 0.001).