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.
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 con-
servation 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 agricul-
tural 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
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.
A green algae bloom sprawls
across the surface of Lake Erie
(to the south), which straddles
the U.S.-Canada border,
in October 2011.