Effekter av salthalter och ljusexponering på zooplanktonpopulationer

Sammanfattning: Abstract Eutrophication and salinization are both major threats to lake ecosystems and the contaminants can alter the structure of freshwater lake ecosystems, resulting in a loss of biodiversity and ecosystem services. Zooplankton and phytoplankton are key components in all aquatic ecosystems as they maintain a healthy quality of the water and they are also an important part of the food chain. Studies show that eutrophication and salinization have severe negative effects on the zooplankton community. This study compares zooplankton communities in 36 mesocosms of eutrophicated waters with nine treatments of salinity and light exposure. The dataset was provided by Associate Professor Lovisa Lind-Eirell, using a randomized design with three levels salt concentrations (15, 250, and 1000 mg of chloride/L of highly eutrophicated waters, in combination with three levels (10%, 35% and 70%) of ambient sunlight. The hypothesis and expected results were a significant decline in zooplankton species richness and population sizes, in treatments with high salinity and low light exposure. The hypothesis was partly correct as nauplii and copepod populations declined treatments of high salinity, whereas cladocerans and rotifers seem to have a saline tolerance which corresponds with other studies. More research is required regarding the combined effects pollutants have on our environment and our ecosystem services. If we wish to keep freshwater ecosystems healthy, prevent further loss of diversity and keep utilizing ecosystem services such as drinking water of good quality, a change of human actions is necessary. More research of interactive effects is needed to better understand the extent of the damage to freshwater ecosystems. Actions to prevent further loss of biodiversity and ecosystem services are necessary but the threats have been acknowledged and finding solutions is currently a work in progress on a global scale.