Abstract

Algal blooms occur frequently in lakes and oceans and the causes and consequences of those are often studied. In this study, we focus on a less well known type of algal bloom by the freshwater raphidophyte Gonyostomum semen. This species' abundance and occurrence is increasing, especially in brown water lakes, the most abundant lake type in the boreal zone. The aim of the study was to investigate which environmental factors are associated with G. semen by statistical evaluation of field data of 95 Swedish lakes over five years. Although we found G. semen to be associated with dark waters it was, contrary to our expectations, mainly high concentrations of iron, and only to a lesser extent high TOC (total organic carbon) concentrations, that were associated with blooms of G. semen. In addition, high phosphorus concentrations and low pH also appear to facilitate G. semen blooms. We suggest that browning of lakes caused by increased iron concentrations may decrease net heterotrophy by fostering heavy algal blooms, i.e. the opposite to commonly assumed effects of increased DOM (dissolved organic matter).

Published in

Scientific Reports
2018, Volume: 8, article number: 13463
Publisher: NATURE PUBLISHING GROUP

SLU Authors

• Östman, Örjan

  • Department of Aquatic Resources (SLU Aqua), Swedish University of Agricultural Sciences
    

• Drakare, Stina

  • Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Oceanography, Hydrology, Water Resources
Ecology


Publication identifier

DOI: https://doi.org/10.1038/s41598-018-31892-7

Permanent link to this page (URI)

https://res.slu.se/id/publ/96564