Hydrology and Land Surface Studies
Didymosphenia geminata: Algal blooms in oligotrophic streams and rivers
Article first published online: 28 MAY 2011
Copyright 2011 by the American Geophysical Union.
Geophysical Research Letters
Volume 38, Issue 10, May 2011
How to Cite
2011), Didymosphenia geminata: Algal blooms in oligotrophic streams and rivers, Geophys. Res. Lett., 38, L10405, doi:10.1029/2010GL046599., , , , , , , and (
- Issue published online: 28 MAY 2011
- Article first published online: 28 MAY 2011
- Manuscript Accepted: 18 APR 2011
- Manuscript Revised: 15 APR 2011
- Manuscript Received: 24 DEC 2010
- algal blooms;
 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.