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Influence of outbreak of macroalgal blooms on phosphorus release from the sediments in Swan Lake Wetland, China

Author:
Gao, L., Wei, Q., Fu, F., Shao, H.
Source:
Plant biosystems 2013 v.147 no.4 pp. 1175-1183
ISSN:
1724-5575
Subject:
Chaetomorpha, biomass, coasts, hydrologic cycle, lakes, macroalgae, pH, phosphorus, sediments, water quality, water treatment, wetlands, China
Abstract:
Macroalgal blooms have occurred worldwide frequently in coastal areas in recent decades, which dramatically modify phosphorus (P) cycle in water column and the sediments. Rongcheng Swan Lake Wetland, a coastal wetland in China, is suffering from extensive macroalgal blooms. In order to verify the influence of macroalgal growth on sediment P release, the sediments and filamentous Chaetomorpha spp. were incubated in the laboratory to investigate the changes of water quality parameters, P levels in overlying water, and sediments during the growth period. In addition, algal biomass and tissue P concentration were determined. In general, Chaetomorpha biomasses were much higher in high P treatments than in low P treatments. Compared with algae+low P water treatment, the addition of sediments increased the algal growth rate and P accumulation amount. During the algal growth, water pH increased greatly, which showed significant correlation with algal biomass in treatments with high P (P < 0.05). P fractions in the sediments showed that Fe/Al–P and organic P concentrations declined during the algal growth, and great changes were observed in algae+low P water+sediment treatment for both. As a whole, the sediments can supply P for Chaetomorpha growth when water P level was low, and the probable mechanism was the release of Fe/Al–P at high pH condition induced by intensive Chaetomorpha blooms.
Agid:
1230885