Submitted to: Journal of Soil and Water Conservation
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/16/2015
Publication Date: 3/9/2015
Publication URL: http://handle.nal.usda.gov/10113/60955
Citation: Smith, D.R., King, K.W., Williams, M.R. 2015. What is causing the harmful algal blooms in Lake Erie? Journal of Soil and Water Conservation. 70(2):27A-29A.
Interpretive Summary: In recent years, harmful algal blooms in Lake Erie have been increasing in size, and the release of a algal toxin, microcystin, resulted in the city of Toledo, Ohio shutting down drinking water to their 400,000 residents in August, 2014. This paper discusses 25 potential agricultural causes for the algal blooms in Lake Erie. None of these have acted alone to induce the increasing size of the algal blooms, but they are likely acting in concert to result in a “perfect storm” of conditions that are right to create these large blooms. This information is important for public consumption, because it is imperative that scientists start focusing on what is truly causing the algal blooms and how we can address these to improve water quality this critical natural resource.
Technical Abstract: Harmful and nuisance algal blooms have been increasing in size and extent since about 2000. In recent years, the release of the algal toxin microcystin has become a growing concern and has resulted in the inability to use water from Lake Erie as a drinking water source to the 400,000 residents of Toledo, Ohio in August, 2014. Farmers in the Western Lake Erie Basin have received the brunt of the blame for the phosphorus loading to the lake that is the root cause of the algal blooms. In this paper, we identify 25 possible causes for increased soluble P loading to Lake Erie. Briefly, these include: climate change, commodity prices, cropping systems, crop nutrient efficiency, ethanol production, fertilizer placement, fertilizer rates, fertility recommendations, fertilizer sources, Round-Up Ready crops, increased soil pH, larger farm size, decrease sediment loading to water, manure, misconceptions by researchers about P, nitrogen, no-till, rental agreements, products sold to increase fertilizer and soil P bioavailability, alterations to soil biology, soil testing and analysis, phosphorus stratification in soils, tile drainage and zebra mussels. Without an appreciation for what factors may be influencing increased soluble phosphorus loading, researchers may not be focused enough to identify potential solutions and decision makers will not be able to manage land in a fashion to curb phosphorus losses to the lake. This paper sets a framework from which future research and farm management may be implemented to target the phosphorus problem in Lake Erie.