Water Prize
Fall turnover in the Skeisvatnet Lake
By Vibeke Aas and Ingunn Gjærde, Skeisvang Upper Secondary School
A finalist for the 2010 Stokholm Junior Water Prize, this paper explores the question of how the nutrient combinations and temperature are changed in the Skeisvantnet Lake during fall turnover.
Seasonal changes are important for the maintenance of the biological diversity of a lake. During the fall changes will occur in a lake regarding for example temperature and substance composition. We wanted to study these annual changes in the Skeisvatnet Lake during fall 2009. Several water samples were collected from the lake on five separate occasions in the period 17.09.09 to 17.12.09. The water samples were analysed by us using the following analytical methods: Pasco Xplorer GLX-data logger, a quicktest set from Riedel-de Haën and a comparative professional analysis carried out by Haugaland Environmental Centre (Haugaland Miljøsenter). The temperatures measured shows that fall turnover is very likely to happen in Skeisvatnet. This view is strengthened by collected data showing substantial changes in the nutrient combinations in the water at different depths of the lake. The Skeisvatnet Lake is not exempt from the rule of annual fall turnover.
