Cleaning Up Algal Blooms

By Novid Parsi
Green algae bloom on Lake Erie

Projects take aim at water-supply hazard.

Beware the algae. As water temperatures rise—and as fertilizer and sewage runoff increases—lakes and rivers around the world are seeing a drastic uptick in harmful algal blooms (HABs). Such blooms can rob these waters of oxygen and produce toxins, threatening the well-being of aquatic species as well as people who rely on affected areas as sources of fresh water and food.

“The frequency and distribution of HABs and their impacts have increased considerably in recent years, both in the United States and globally,” says Alan J. Lewitus, PhD, chief of ecosystem stressors research branch, National Oceanic and Atmospheric Administration (NOAA), Silver Spring, Maryland, USA.

In response, teams at governments and not-for-profits around the globe are tackling the problem on a range of fronts, launching projects to prevent HABs as well as restore water systems to health. Some even treat blooms as an asset to be farmed.

A Costly Global Threat

Some of the world’s largest bodies of water have been imperiled by HABs, including Lake Victoria in Africa, the Baltic Sea in northern Europe and the Caspian Sea in west Asia. HABs place added pressure on an already threatened resource: fresh water. About 783 million people currently lack an adequate supply of fresh water, according to the United Nations.

About 783 million people currently lack an adequate supply of fresh water, according to the United Nations.

In addition to environmental costs, HABs carry hefty economic costs by disrupting commercial fishing and fouling beaches that depend on tourism. In Australia, HABs in lakes and rivers cost at least US$160 million annually, while in the United States, HABs in coastal waters cost at least US$82 million each year, according to the NOAA. In just three European countries—Greece, Italy and Spain—the cost reaches a staggering €300 million per year, according to the European Commission.

Reining in the Runoff

Last year, a HAB in Lake Erie led to elevated toxin levels that compromised water supplies in the lakeside U.S. city of Toledo, Ohio. Residents went two days without tap water. It was the first time a toxic bloom closed a large U.S. city’s drinking water plant.

To restore Lake Erie and the four other Great Lakes—the world’s largest source of fresh surface water— the U.S. Environmental Protection Agency (EPA) in 2010 launched the four-year US$1.6 billion Great Lakes Restoration Initiative (GLRI), which was renewed last year for an additional five years. (The U.S. Congress approved US$300 million for GLRI funding this year; the EPA hopes for equal annual funding through 2019.) Working with 15 other federal agencies, the GLRI—the largest conservation program in U.S. history—has thus far funded over 2,200 projects, many of which address HABs.

“One reason HABs exist is the nutrient runoff that’s occurring from both agricultural and urban areas,” says Wendy Carney, deputy director, Great Lakes National Program Office, U.S. EPA, Chicago, Illinois, USA. Reducing the flow of nutrients like phosphorous and nitrogen—used widely by farmers to grow crops—into the lakes is “the one factor we can try and put a dent in so we’re not having these HABs.”

GLRI-funded projects range from educating farmers to implement conservation practices such as planting cover crops—which reduce soil erosion, reducing nutrient runoff—to testing soil nutrient levels so fertilizer isn’t added to soil unnecessarily.

Delayed benefits realization is a major challenge facing GLRI projects, along with other HAB initiatives around the world. It could be five years before a project that works to reduce nutrient runoff results in the reduction, Ms. Carney explains. To track such delayed benefits, the GLRI carefully monitors both projected and achieved results.

Cross-Border Collaborations

Algal blooms don’t respect international boundaries, so project teams are culling expertise and lessons learned from initiatives across borders.

Since 2007, China’s Lake Taihu has seen massive HABs that have left millions of people without clean drinking water. In 2014, Hohai University in Nanjing, China partnered with two U.S. environmental research institutions—the Desert Research Institute and the Nevada Center of Excellence—to form a joint research effort that will launch projects researching HABs in Lake Taihu.

Similarly, in 2012, Guatemala’s Office of Economic Growth partnered with the U.S. Agency for International Development to launch a two-year US$1.2 million project to research HABs in Lake Atitlán. Each year, thousands of tons of trash, fertilizer and raw sewage are dumped into the lake, one of Guatemala’s top tourist attractions. The project, United for Lake Atitlán, concluded that officials will have to do what their counterparts have done to protect Lake Tahoe in Nevada, USA since the 1960s: export wastewater out of the lake.

Rapid Responses

While some projects target either the prevention of HABs or the restoration of the waters where they thrive, others aim to quickly detect bloom outbreaks.

In 2012, a HAB partly shut down the shellfish industry in the Australian state of Tasmania at a cost of AU$23 million because the bloom was identified too late, and shellfish became toxic. In October, the University of Tasmania launched an AU$600,000 project to create a rapid shellfish and water toxin screening test that will reduce testing time from days to hours.

Another project aims to both detect and treat HABs. A European consortium last year launched the Dronic Project, a 30-month, €3.3 million effort to develop a water-based robotic system that uses unmanned surface vehicles and ultrasonic technology to autonomously detect and dispose of harmful algae.

Still other initiatives see HABs not as a blight, but as a potential asset. In 2013, Sweden launched Seafarm, a five-year, SEK24.7 million project in the Baltic Sea that will collect overabundant algae, which consumes oxygen and can overwhelm an ecosystem, creating a “dead zone.” Seafarm will cultivate it in underwater farms to be used as ecofriendly food, medicine, plastic and energy.

“We turn the argument on its head and see algae as a resource,” Fredrik Gröndahl, project manager, KTH Royal Institute of Technology, Stockholm, Sweden, said in a statement.

Originally Published in the April 2015 PM Network Magazine