Using Data Sources to Track Harmful Climate Crisis-Fueled Algal Blooms

At this time of summer, an increasingly common kind of pollution in many places begins making seafood toxic, sickening swimmers, and sometimes killing people’s dogs.

We have some databases that can help reporters track “harmful algal blooms” (HABs). Also known as red tides, these blooms of particular kinds of algae are harmful to health.

In many places, HABs are getting worse and more frequent. Hence the data — which can help you follow trends.

Summer brings higher water temperatures. Climate heating often makes it worse. And the algae that people find harmful grow more abundant in hotter water.

Farming, fertilizers and increased stormwater runoff increase pollution from nutrients like phosphorus and nitrogen that make the algae grow. Salinity can also be a trigger.

The worst villains are blue-green algae — which are not technically algae at all. They are cyanobacteria, actual bacteria that photosynthesize.

Among other things, they produce toxins like microcystins and domoic acid that make people and other creatures sick. To be fair, they also played a key role in creating the oxygen atmosphere that made life on land possible.

There’s much more to know about the many kinds of HABs. For now, let’s talk about the data.

Where the Data Comes From

There are several potential sources of HAB data; none of them is perfect. Let’s look at each.

Image: Courtesy of NOAA

• Harmful Algal BloomS Observing System (HABSOS; the funny S is intentional). This system is run by the National Oceanic and Atmospheric Administration (NOAA). It’s online, open and searchable. It gives you individual events, presented in map format via ArcGIS. Its biggest limitation is that it only looks at the Gulf of Mexico.
• Harmful Algal Event Database (HAEDAT). This system is run by agencies within UNESCO. It is worldwide in scope. Data is as reported by member nations — which creates comparability and accuracy issues.
• US National Office for Harmful Algal Blooms. Based at the Woods Hole Oceanographic Institute in Massachusetts and funded by NOAA, this office is an international research clearinghouse. Their data does go into HAEDAT, but they present it better. Events are mapped to areas in the US and separated according to type of toxic organism.

How to Use the Data Smartly

Of course you can use the data to look at time-trends — are they getting worse with climate heating and higher water temperatures? (Spoiler alert: They are.)

This may be meaningful for some purposes. At a global and national scale, it really matters. The US Environmental Protection Agency is among those already doing a pretty good job of explaining the climate connection.

But there is more to report about than just the global heat wave. Your audience may be interested in more immediate impacts, and the data can help you tease these out.

For example, your publication may be located in an area where tourism is a big industry and swimmable beaches have economic importance. You could overlay HAB data with data on beach closures.

Or you may live in Ohio, where a shallow and warm Lake Erie receives agricultural runoff polluted with nutrients. Tom Henry at the Toledo Blade has written for years about how algal blooms have threatened the city’s drinking water. This happens elsewhere, too. It’s a reminder that many HABs happen in the Great Lakes and many smaller inland lakes.

In other places, seafood may be an economically or culturally important industry. Some of the organisms that cause HABs cause shellfish poisoning — posing a serious health risk to anyone who eats the affected seafood.

Dead zones are better known to the people who suffer their effects than to the people (e.g., farmers) who cause them. Fertilizer running off of fields and flowing down the Mississippi River nourishes algae and other plants growing in the Gulf of Mexico. When algae die, bacteria consume them and rob the waters of oxygen.

Dead zones happen in other waters, too. Of course the dead zone is not toxic to humans. Just to fish.

This post was originally published by the Society of Environmental Journalists Reporter’s Toolbox and is republished here with permission. 

Joseph A. Davis is a freelance writer/editor in Washington, D.C. who has been writing about the environment since 1976. He writes SEJournal Online’s TipSheet, Reporter’s Toolbox and Issue Backgrounder, and curates SEJ’s weekday news headlines service EJToday and @EJTodayNews. Davis also directs SEJ’s Freedom of Information Project and writes the WatchDog opinion column.