A team of researchers at Tuft’s University published the results of a new study today in the online journal Environmental Science & Technology, predicting the largest increase in HABs will occur in the Northeast of the United States, while the biggest economic harm will be felt in areas of the Southeast.
The research is part of a larger, ongoing effort to quantify and monetize the degree in which HABs brought on by climate change will impact and damage various sectors in the U.S.
“Some of the biggest CyanoHAB impacts will occur in more rural regions, such as those in the Southeast and Midwest – areas that don’t often come up in conversation about unavoidable effects of climate change,” said Steven C. Chapra, Ph.D., lead author and Louis Berger Chair of Civil and Environmental Engineering in the School of Engineering at Tufts. “The impact of climate change goes way beyond warmer air temperatures, rising sea levels, and melting glaciers.”
Cyanobacteria, usually seen in harmful algae blooms, have been around for over 3.5 billion years and are one of the Earth’s oldest oxygenic photosynthetic organisms. They are very resilient and adaptive to a wide range of climate conditions, and because of this, global warming is playing a major role in the expansion and persistence of this organism.
Using computer modeling, along with a hydrologic/water quality network model of U.S. lakes and reservoirs, climate change projections from five general circulation models, two cyanobacterial growth scenarios, and two greenhouse gas emission scenarios, the scientists were able to capture a range of future scenarios.
Basically, the research indicates that as water temperatures increase, more demanding and costly nutrient controls will be necessary in order to maintain current water quality.
Science and technology steps in to offer solutions
Between 30 and 48 million Americans get their drinking water from lakes and reservoirs, and periodically, these sources are contaminated by HABs. On August 2, 2014, about 500,000 residents of Toledo, Ohio, woke up to a “do not drink” warning, declaring the city’s water supply contaminated with a HAB. Ohio Gov. John Kasich declared the State of Emergency, allowing water to be brought in.
And that incident is just one of many we have seen over the past few years, and it’s not just drinking water for humans, but recreational and agriculture uses have also been affected by HABs. For many years, any monitoring of bodies of water has been done by researchers on the ground and by conscientious citizens, like boaters or fishermen reporting occurrences of algae blooms.
Such a scenario has been going on in the Finger Lakes region of New York. Of the 11 Finger Lakes, only Seneca, Skaneateles and Canandaigua lakes have been spared this year.
But monitoring bodies of water can be time-consuming and testing water samples for levels of different toxins is an added expense some smaller communities in rural areas may not be able to afford. To meet the need for better monitoring of bodies of water across the country, researchers have come up with a couple of unique innovations.
Satellite data and images identify HABs
In 2014, NASA, the National Oceanic and Atmospheric Administration, the Environmental Protection Agency and U.S. Geological Survey began a five-year research project that relies on space-based sensors originally designed to detect variations in ocean color.
Acknowledging the expense of using researchers on the ground, Keith Loftin, lead USGS principal investigator for the project, said, “Remotely sensed data provides a perspective that allows us to capture occurrence, persistence and harmful algal bloom movement through time while covering the maximum area.”
Earlier this year, the sky-high monitoring paid off when satellite data helped detect an algae bloom in a Utah Lake near Salt Lake City before officials on the ground knew about it. The ultimate goal of the program is to use satellite data to monitor the more than 1,800 lakes across the nation.
The other aspect of monitoring for HABs is finding out what kind of toxin and its levels may be in the water. Tom Johengen, associate director of the Cooperative Institute for Great Lakes Research at the University of Michigan and his colleagues are experimenting with a new technology – a lake-bottom “robotic lab” that will test water in Lake Erie and give information and early warnings about pollution.
The robotic Environmental Sample Processor
Looking somewhat like a huge garbage compactor unit, the environmental sample processor, or ESP, is basically a “lab in a can.” It is programmed to test a water sample from a body of water once or twice a day and transmit the results wirelessly to researchers. It is time-saving and cost effective, compared to the current means of collecting and processing water samples, where the results of testing can sometimes take several days.
An ESP was positioned on the bottom of Lake Erie, four miles from the water intake for the Toledo municipal water supply in July. It is the first “Lab in a can” to be used on a freshwater system in the U.S. There are ESPs off the coast of Maine and Washington state, monitoring ocean water for toxins that are harmful to shellfish.
In addition to climate change, the other problem exacerbating the algae blooms seen in our lakes and waterways is agricultural run-off. And it is questionable if we will ever see this problem solved. “Bloom eradication is likely never going to happen, but we can absolutely reduce the size and impact of these blooms,” says Tim Davis, an ecologist formerly of the National Oceanic and Atmospheric Administration’s (NOAA) Great Lakes Environmental Research Laboratory.
