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Didymosphenia geminata : Algal blooms in oligotrophic streams and rivers
Author(s) -
Sundareshwar P. V.,
Upadhayay S.,
Abessa M.,
Honomichl S.,
Berdanier B.,
Spaulding S. A.,
Sandvik C.,
Trennepohl A.
Publication year - 2011
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2010gl046599
Subject(s) - diatom , streams , biogeochemical cycle , biomass (ecology) , biogeochemistry , environmental science , phosphorus , ecology , algal bloom , algae , algal mat , bloom , temperate climate , oceanography , biology , phytoplankton , nutrient , chemistry , computer network , computer science , geology , organic chemistry
In recent decades, the diatom Didymosphenia geminata has emerged as nuisance species in river systems around the world. This periphytic alga forms large “blooms” in temperate streams, presenting a counterintuitive result: the blooms occur primarily in oligotrophic streams and rivers, where phosphorus (P) availability typically limits primary production. The goal of this study is to examine how high algal biomass is formed under low P conditions. We reveal a biogeochemical process by which D. geminata mats concentrate P from flowing waters. First, the mucopolysaccaride stalks of D. geminata adsorb both iron (Fe) and P. Second, enzymatic and bacterial processes interact with Fe to increase the biological availability of P. We propose that a positive feedback between total stalk biomass and high growth rate is created, which results in abundant P for cell division. The affinity of stalks for Fe in association with iron‐phosphorus biogeochemistry suggest a resolution to the paradox of algal blooms in oliogotrophic streams and rivers.