5pm potluck followed at 6pm by a presentation "Freshwater Acidification: A Growing Concern?" by Tim Sesterhenn, Morningside University Associate Professor of Biology.

Acidification of the oceans is a well-known consequence of climate change, and there are recent indications that freshwater ecosystems may also be subject to increased acidification. Freshwater life is typically more resilient to changes in pH because of the different chemistry of saltwater and freshwater habitats, but there is an emerging trend of negative effects due to elevated levels of carbon dioxide. Tim will describe general background and trends in research, and some experiments he has done with his students investigating effects of acidification on behavior and growth of freshwater snails.