What are Harmful Algal Blooms?
There are many species of single-celled organisms living in the Great Lakes, including algae. When certain conditions are present, such as high nutrient or light levels, these organisms can reproduce rapidly. This dense population of algae is called a bloom. Some of these blooms are harmless, but when the blooming organisms contain toxins, other noxious chemicals, or pathogens, it is known as a harmful algal bloom, or HAB. HAB's can cause the death of nearby fish and foul up nearby coastlines, and produce harmful conditions to aquatic life as well as humans.The focus of this research project is to determine the factors controlling microcystin production and to develop methods for determining cyanobacteria blooms from satellite imagery. Imagery is currently available, but we do not know how to discriminate toxic /Microcystis/ blooms from other algal blooms within the images. The combined field data and satellite image data produced from the initial efforts of this project are critical first steps in the characterization of bloom dynamics and development of future bloom forecasting tools.
Click on photos to link to microcystin concentrations.
The data appearing on these pages is generated based on an event response research program. The project was not designed to monitor waters for potential human health impacts - it was designed to answer research questions relating to the community dynamics of algal blooms in the Great Lakes. However, the project leaders and the Center of Excellence for Great Lakes and Human Health feel strongly that when research reveals human health implications, the responsible course of action is to make that data as publicly available as possible.
Sampling Protocol
This project will be regularly sampling Bear Lake, Muskegon Lake, western Lake Erie and Saginaw Bay. Satellite images (experimental MODIS chlorophyll products) are used to guide sampling. These images are related to (but not identical with) the MODIS true color imagery appearing on these web pages. Identification of a 'probable bloom' on the satellite image triggers sampling. Unless otherwise noted, samples are taken at the surface. This is done to match sampling to the bloom dynamics visible to the satellite, not to match human health guidelines. However, surface samples are most representative of the portion of the water column with which recreational users (boaters, swimmers, jet skiers, etc.) are most likely to come into contact.
Samples are subjected to an initial screening based on an ELISA technique for microcystin quantification. Measured concentrations are intracellular concentrations of microcystin. Reported concentrations take into account initial sample volume to give a concentration of (intracellular) microcystin in the water. Most microcystin is retained in the cells until cell death (unlike other toxins) so our reported microcystin concentration is a good estimate of whole-water microcystin concentration for new and peak blooms. Concentrations of microcystin in waters containing many dying cells (a dying bloom) may be underestimated. Our ELISA screening quantifies total microcystin. Most guidelines are based on microcystin-LR or microcystin-LR equivalents. Microcystin-LR is one of the most toxic strains of microcystin - it is also among the most common strains in the Great Lakes.
Join HABCOMM, our Harmful Algal Bloom listserv, to stay informed on current and new HAB research findings, post questions, and keep up to date on events, meetings, and conferences. To join send an email to: , with the words “subscribe habcomm” written in the body of the email. *You don't need to have any text in the subject/re: line.*
