A new study from the University of Wisconsin-Madison recently showed that the invasion of a non-native species into a freshwater lake can have dramatic effects on ecosystem services – the benefits provided by ecosystems that contribute to making human life both possible and worth living. Some of the best examples of ecosystem services from freshwater systems include clean water, fisheries, and recreation.
Linkages between the lake food web and ecosystem services (Walsh et al. 2016 Proceedings of the National Academy of Sciences USA).
In the study, an old friend of the Aquatic Ecology Lab, the spiny water flea (Bythotrephes), has invaded Lake Mendota, WI. The invader rapidly grew to a large population size, and consequently, consumed large amounts of the herbivore Daphnia. Daphnia is critical to lake food webs because it is so efficient at grazing on algae. In the study, the substantial drop in Daphnia led to a decrease in water clarity in Lake Mendota. In order to reverse the effects of the spiny water flea, phosphorus, a key nutrient that stimulates algal growth, would have to be reduced by 71%, with an associated price tag of $86.5 – 163 million.
As massive as these costs are, consider for a moment that this is just for a single lake – invasive species can readily be dispersed to many lakes and rivers as unintentional hitchhikers on boats, fishing lines, and in live wells (amongst many other sources). We all have a part to play in reducing the spread of these harmful species – otherwise, it might cost us!
For more information about aquatic invasive species and ways to prevent spread, please visit these sites: