Nutrients and eutrophication: introduction

Abstract

Cultural eutrophication stimulated by anthropogenic-derived nutrients represents one of the most common forms of compromised surface water quality in many developed and developing countries (Schindler 2012). In fresh water, both nitrogen (N) and phosphorus (P) can potentially contribute to eutrophication (Carpenter et al. 1998). In lakes it is more common that excessive P inputs are the primary cause of eutrophication (Schindler 1977) although both global (Elser et al. 2007) and national surveys (Abell et al. 2011a) have increasingly highlighted excessive N inputs as an equal or more important cause. Debate on the relative roles of N and P limitation of lake phytoplankton is highly contentious, with a P-limitation paradigm (Schindler et al. 2008) challenged by those who contend that both P and N control are key elements of eutrophication management in freshwater systems (e.g. Conley et al. 2009; Scott and McCarthy 2010). Eutrophication of temperate estuaries and coastal waters is also common, but in contrast to fresh water, N is more commonly the controlling nutrient (Carpenter et al. 1998).