A fresh (water) perspective on the impacts of the NAO on North Atlantic ecology

Abstract

North Atlantic climate variability does not only have an influence on North Atlantic ecosystems as described in the previous chapters and by Drinkwater et al. (2003), but influences terrestrial and freshwater ecosystems across the Northern Hemisphere (Ottersen et al. 2001; Mysterud et al. 2003; Stenseth et al. 2002; Straile et al. 2003b). Its impact on freshwater ecosystems has been documented on an area ranging from Lake Mendota in the United States to Lake Baikal in Russia, from Lake Kallavesi in Finland to the Caspian Sea (Straile et al. 2003b). In an increasing number of studies, the North Atlantic Oscillation (NAO) is shown to influence the physics, chemistry, as well as the biology of rivers and lakes, with biological impacts encompassing various trophic levels. A review on NAO impacts was recently provided by Straile et al.(2003b) and will not be repeated here. Instead, this chapter is an essay on selected aspects of NAO impacts on freshwater ecosystems, which might shed somelight or pose new questions on the NAO impacts on the North Atlantic.