Modelling the response of phytoplankton in a shallow lake (Loch Leven, UK) to changes in lake retention time and water temperature

Abstract

Article (refereed) -postprint Elliott, J.A.; Defew, L.. 2012 Modelling the response of phytoplankton in a shallow lake (Loch Leven, UK) to changes in lake retention time and water temperature. Hydrobiologia, 681 (1). 105-116. 10.1007/s10750-011-0930-y Contact CEH NORA team at noraceh@ceh.ac.ukThe NERC and CEH trademarks and logos ('the Trademarks') are registered trademarks of NERC in the UK and other countries, and may not be used without the prior written consent of the Trademark owner.1 TitleModelling the response of phytoplankton in a shallow lake (Loch Leven, UK) to changes in lake retention time and water temperature. Keywords:Phytoplankton, retention time, climate change, cyanobacteria, PROTECH This paper has not been submitted elsewhere in identical or similar form, nor will it be during the first three months after its submission to Hydrobiologia. 2 AbstractThe phytoplankton community of Loch Leven in 2005 was modelled and subjected to a combination of different flushing rates and water temperatures in order to assess the lake's sensitivity to these two climatic drivers. Whilst the simulated annual mean total chlorophyll a proved relatively insensitive to these changes, at the species level marked changes were recorded. Some species responded positively to increased temperature (e.g. Aulacoseira), some negatively (e.g. Asterionella), whilst others were negatively affected by increased flow (e.g. Aphanocapsa) and others enhanced (e.g.Stephanodiscus). However, this relationship with flow was season dependent with, for example, a simulated increase in summer inflows actually benefiting some species through increased nutrient supply, whereas an equivalent increase in flow in wetter seasons would have negatively affected those species (i.e. through flushing loss).Overall, the simulations showed that the range of species types simulated in the community was sufficient for one species to always benefit from the changing niches created by the multiple climatic drivers applied in this study. The level of exploitation by such a species was only constrained by the nutrient carrying capacity of the system, which led to the overall dampened response in the total chlorophyll a measure, both at the annual and season scale. Thus, whilst overall biomass showed relatively little reaction to the two climatic drivers tested, the phytoplankton community composition responded markedly.

Asynchronous onset of eutrophication among shallow prairie lakes of the Northern Great Plains, Alberta, Canada

“…In principle, climate change can contribute to lake eutrophication through increased water temperature and changes in precipitation regimes (Murdoch et al ., ; Adrian et al ., ). Minimum surface air temperature in Alberta increased by 1.3–2.1 °C (Shen et al ., ) (S1), resulting in increased water temperatures (DeStasio et al ., ) and elevated algal growth rates (Eppley, ; Adrian et al ., ), increased internal phosphorus loading in shallow lakes (Jensen & Andersen, ), and a higher proportion of cyanobacteria in the phytoplankton community (Paerl et al ., ; Elliott & Defew, ; Pätynen et al ., ). However, contrary to expectations, cyanobacterial abundance only increased disproportionately in two of 10 study lakes, suggesting that there was no single response of biota to common thermal forcing (see below).…”

Factsheet KIWK : Stroming en waterbeweging

“…Dergelijke waterbeweging kan ook door scheepvaart worden veroorzaakt (Anthony & Downing, 2003). De aan-en afvoer van water heeft grote invloed op de verblijftijd (Wetzel, 1990) en bepaalt de nutriëntenvracht en -cyclus en daarmee ook de ontwikkeling van de algengemeenschappen (Kronvang et al, 2005;Elliott & Defew, 2011). In sloten kan de aan-en afvoer dicht bij gemalen leiden tot omstandigheden die lijken op stromende wateren, met name wanneer er intensief gepompt wordt.…”