Líffræðifélag Íslands
Líffræðiráðstefnan 2015

Erindi/veggspjald / Talk/poster V45

The dissemination of the invasive diatom Didymosphenia geminata in subpolar oceanic climate – a case study from Iceland

Vaiva Čypaitė (1), Ingi Rúnar Jónsson (2), Jón S. Ólafsson (2), Nadja Ognjanova (3) and David Finger (1)

1. Reykjavik University, School of Science and Engineering, 2. Institute of Freshwater Fisheries of Iceland 3. IBER-BAS, Bulgaria

Kynnir / Presenter: Vaiva Čypaitė

Tengiliður / Corresponding author: Vaiva Čypaitė (vaivacypaite@gmail.com)

The diatom Didymosphenia geminata is a single cell algae which natural habitat is cold fresh water environments with low nutrient content. Rivers in cold climate regions, i.e. mountainous areas in Europe, Asia and North America, is a natural habitat of D. geminata. However during last few decades it has been noticed that population of D. geminata is growing outside its native range. Even though diatoms do not have a direct impact on human health, in high abundance they can change the physical and biological conditions of rivers, influencing nutrient content and fish populations in streams. In Iceland D. geminata is considered as an invasive species. Between 1997 and 2006 monitoring of D. geminata prevalence in Icelandic rivers revealed that these diatoms are widely spread. The main concern is the effect of D. geminata on the stream ecology. In the current study we aim to identify main factors which influence growth and expansion of D. geminata in Icelandic rivers. During three field excursions we will monitor the presence of D. geminata in the River Elliðaár, Lake Elliðavatn and the tributaries Suðurá and Hólmsá and compare the different locations to meteo-hydrological conditions. By comparing the new data to previous observations from 1994 and 2006 we will identify the possible effect of D. geminata on other algae and invertebrates. By performing a trend analysis we will try to identify the driving factors enhancing the distribution of D. geminata. Finally, we will compare the dispersion rates of invasive species in Iceland to dispersion rates observed by project partners in south-eastern Europe (Bulgarian site) in order to characterise dispersion rates according to their climatic setting.