Goals & Objectives:
The overall goal of this project is to improve harmful algal bloom forecasting and decision support tools for Lake Erie that are used by water treatment plant managers, recreational boaters, beach users, and anglers. This will be accomplished through 1) developing predictive relationships between environmental variables and the buoyancy and vertical distribution of Microcystis colonies, 2) understanding the links between Microcystis physiological status and buoyancy/growth, 3) assessing the effects of the HAB on the Lake Erie food web, 4) assessing which stakeholder groups are currently using HAB nowcast/forecast information, for what purpose, and how knowledgeable they are about the current forecasts, and 5) developing communications tools and HAB forecasting information to meet user needs.

Theoretical Justification, Social Benefit, or Significance:
The proposed research project is important for society because harmful algal bloom (HAB) forecasts increase the value of ecosystem services that Lake Erie provides to society. Lake Erie provides drinking water to 11 million people. HAB forecasts allow treatment plant operators to focus additional testing and treatment chemical usage on times when risk is highest. HAB forecasts allow anglers, recreational boaters, and beach users to direct their activities to locations and times that minimize their exposure to HABs, thereby supporting the regional tourism economy.

Lake Erie is the shallowest and most productive of the Laurentian Great Lakes of North America. Lake Erie supports recreational and commercial fisheries in addition to recreation and tourism industries that are of great importance to the regional economy. During the 1960s, Lake Erie suffered from degraded water quality and hypoxia, and played an important role in the environmental movement that led to the passing of the Clean Water Act in 1972. Subsequent reductions in nutrient loads led to improved water quality. However, in the mid-1990s harmful algal blooms (HABs) re-emerged as a problem in Western Lake Erie. The HABs are dominated by the colony-forming cyanobacterium Microcystis aeruginosa, which produces a family of hepatotoxins known as microcystins that can cause health impacts through contact exposure or ingestion. The severity of HABs has increased, leading to record-setting blooms in both 2011 and 2015, and to the contamination and shutdown of the City of Toledo drinking water supply in 2014.

The UM School of Natural Resources and Environment has a strong research collaboration with NOAA (National Oceanic and Atmospheric Administration) facilitated by the Cooperative Institute for Limnology and Ecosystems Research (CILER). CILER researchers are located at the NOAA Great Lakes Environmental Research Laboratory in Ann Arbor, MI. NOAA provides a suite of information products to the public and to local managers for decision support, which present the current status of Lake Erie HABs (nowcast) and predictions on the extent and distribution of HABs five days into the future (forecast). Nowcast information includes in-lake monitoring of water quality and HAB indicators, as well as toxin concentrations. Satellite remote sensing provides a lake-wide view of HAB distribution and intensity, which is combined with meteorological forecasts, hydrodynamic models, and Lagrangian particle tracking models to provide continuous nowcast and forecast estimates of HAB intensity and distribution. Ecological impacts of HABs are evaluating through use of food web models. Users of this information include drinking water treatment plant managers, anglers, recreational boaters, and beach users.

In order to predict whether specific locations will be impacted by HABs in the near future, simulation models have been developed that attempt to quantify the processes that are important in determining changes in HAB distribution and intensity, including movement due to water currents (advection), vertical mixing due to turbulence, and buoyancy of Microcystis colonies. Growth and decay of Microcystis colonies is not simulated in present models, but may be important on the 5 to 10-day forecast time scale under certain conditions. Simulation of the vertical distribution of buoyant Microcystis colonies in the water column has been shown to improve forecast skill.

Further research is needed to improve forecast models and to communicate the forecast information in a way that meets the needs of users. The buoyancy of Microcystis colonies is an important parameter in the forecast model, but is based on limited data. It is likely that forecast skill could be further improved by establishing the dependence of buoyancy on environmental variables such as light exposure, nutrients, and temperature. In the area of communication, further research is needed to evaluate and document the needs of forecast user groups. User needs may be established by means of focus groups and semi-structured interviews. Long-term effects of HABs on fish production and the food web, for example by replacement of edible phytoplankton with inedible cyanobacteria or by bioaccumulation of microcystin, are unknown and can be investigated using food web models that have been developed at CILER/GLERL.

Specific Activities & Duration:

It is anticipated that five students will work on this project part time during the school year and full time during the summer. A common problem that limits the quality of SNRE projects is that students often seek out paid internships during their second summer when they are supposed to be working on projects, which limits the time they can dedicate. To overcome this problem, we have obtained funding from NOAA-GLERL and CILER to support five students in the form of summer research stipends for $6250 each.

Specific activities that are proposed as part of this project include,

1. Student 1. Will be responsible for weekly collection (June – October) and laboratory analysis of discrete water quality and HAB samples from Lake Erie to document spatial, temporal, and vertical distribution of HABs and to test model assumptions and performance.
2. Student 2. Will execute laboratory measurements of Microcystis colony buoyant velocity to establish quantitative relationships between buoyancy and associated environmental and physiological variables.
3. Student 3. Will be in charge of laboratory experiments to establish quantitative relationships between Microcystis physiology and nutrient status on buoyancy and growth.
4. Student 4. Will apply an existing Lake Erie food web model to estimate the impact of HABs on food webs and fisheries.
5. Student 5. Will use human dimension/ social science methodologies to identify and assess knowledge gaps and research information needs of user groups, such as drinking water intake managers, state environmental managers, charter fishing captains and public health officials and develop a outreach plan to facilitate the transfer of scientific information to meet needs of user groups.

Integrative Approach:

This project will integrate the social science of behavior, communication, and education with physical and biological aspects of ecology to improve the usefulness of information products related to Lake Erie HABs for user communities.

We will facilitate a creative and rigorous team problem-solving experience through a structured mentoring approach that will include regular group meetings and topical training at appropriate stages in the project, as outlined in Box 1. We anticipate that the student team will produce results of a quality that may be used in future peer-reviewed journal publications. Authorship criteria will be discussed, and students whose contributions are used in future publications will be given the opportunity to serve as co-author.