Review Status, causes and controls of cyanobacterial blooms in Lake Erie Morgan M. Steffen a , B. Shafer Belisle a , Sue B. Watson b , Gregory L. Boyer c , Steven W. Wilhelm a a Department of Microbiology, The University of Tennessee, Knoxville, TN 37996, USA b Aquatic Ecosystem Management Research Division, Science & Technology Branch, Environment Canada, National Water, Canada c College of Environmental Science and Forestry of the State University of New York, Syracuse, NY 13210, USA abstract article info Article history: Received 4 July 2013 Accepted 2 October 2013 Available online xxxx Communicated by Joseph Makarewicz Keywords: Lake Erie Microcystis CyanoHAB Eutrophication Climate change The Laurentian Great Lakes are among the most prominent sources of fresh water in the world. Lake Erie's infamous cyanobacterial blooms have, however, threatened the health of this valuable freshwater resource for decades. Toxic blooms dominated by the cyanobacterium Microcystis aeruginosa have most recently been one of primary ecological concerns for the lake. These toxic blooms impact the availability of potable water, as well as public health and revenues from the tourism and fishery industries. The socioeconomic effects of these blooms have spurred research efforts to pinpoint factors that drive bloom events. Despite decades of research and mitigation efforts, these blooms have expanded both in size and duration in recent years. However, through continued joint efforts between the Canadian and United States governments, scientists, and environmental managers, identification of the factors that drive bloom events is within reach. This review provides a summary of historical and contemporary research efforts in the realm of Lake Erie's harmful cyanobacterial blooms, both in terms of experimental and management achievements and insufficiencies, as well as future directions on the horizon for the lake's research community. © 2014 International Association for Great Lakes Research. Published by Elsevier B.V. All rights reserved. Contents Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 Current status of the cyanobacterial community and cyanotoxins in Lake Erie . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 The role of nutrients as drivers of Lake Erie cHABs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 Abiotic factors and the success of Cyanobacteria in Lake Erie . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 The continuing saga: current research and policy trends in Lake Erie . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 Introduction The Laurentian Great Lakes are arguably one of the most valuable natural resources in North America, if not the world. This system repre- sents roughly 20% of the Earth's available surface freshwater, a resource that is expected to become increasingly limited in the near future (Schottler and Eisenreich, 1994). Lake Erie alone provides over 7 billion dollars in revenue each year from tourism and fishery industries (United States Department of Agriculture, 2005). For the last two de- cades, however, Lake Erie has again been threatened (as it was in the 1960s and 1970s) by annual blooms of toxic cyanobacteria during sum- mer months. Despite intensive research and management efforts, the duration and toxicity of blooms appear to be expanding in recent years (Stumpf et al., 2012). Proliferation of undesirable plankton, whether in freshwater or marine environments, has long plagued the world's waters (Table 1). Among the Laurentian Great Lakes, Lake Erie is most susceptible to recurring large-scale blooms due to the morphology of the lake, its loca- tion in a temperate climate with warm summer temperatures, and extensive anthropogenic inputs. At an average depth of 19 m, Lake Erie has a relatively short retention time (b 3 years) and consistently reaches temperatures above 25 °C during summer months (Burns et al., 2005; Stumpf et al., 2012; National Weather Service, www.wbuf. noaa.gov/laketemps/laketemps.php, accessed Dec 2, 2013). The lake continues to receive extensive input from agricultural and industrial runoff, despite decades of international efforts to reduce nutrient loading (Waples et al., 2008). Phosphorus (Dolan and Chapra, 2012; Dolan and McGunagle, 2002; Han et al., 2012) and nitrogen (Solomon et al., 2010) are key components in detergents, fertilizers, industrial chemicals, and common herbicides. These compounds and others are increasingly being applied within watersheds, resulting in the delivery of nutrients to the lakes through tributaries, rivers, and non-point Journal of Great Lakes Research xxx (2014) xxx–xxx JGLR-00660; No. of pages: 11; 4C: 0380-1330/$ – see front matter © 2014 International Association for Great Lakes Research. Published by Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.jglr.2013.12.012 Contents lists available at ScienceDirect Journal of Great Lakes Research journal homepage: www.elsevier.com/locate/jglr Please cite this article as: Steffen, M.M., et al., Status, causes and controls of cyanobacterial blooms in Lake Erie, J Great Lakes Res (2014), http:// dx.doi.org/10.1016/j.jglr.2013.12.012