New Challenges with Harmful Algae Renew Interest in Old Techniques


Scientists have developed powerful new molecular and genetic tools to identify harmful algal bloom species during the last 20 years. With these advances, interest has steadily waned in the classic methods of identifying algae by examining them under a microscope. As most of the experts in these methods have already entered retirement, their skills have long seemed likely to permanently disappear from labs across the country. However, emerging environmental challenges are now breathing new life into this dying art.

"With climate change, harmful algal blooms are happening more frequently, over larger geographic areas, and impacting greater numbers of people and marine resources than ever before," said Cynthia Heil, senior research scientist at Bigelow Laboratory for Ocean Sciences. "A lot of these blooms are moving. They’re expanding in range. They’re changing in toxicity."

This increase in uncertainty has created an urgent need for experts who are able to rapidly and accurately identify potential threats by recognizing these species visually. Those monitoring for harmful algal blooms need to know what species they’re looking for before they can molecularly test for them. So, what happens if something unexpected shows up?

In August, we hosted a 10-day, NOAA-funded course designed to teach classic methods of microscopic identification to people responsible for monitoring harmful algal blooms around the country. The course was organized by two of our senior research scientists, Mike Lomas and Cynthia Heil, who enlisted the help of some of the country’s foremost experts in phytoplankton taxonomy: Drs. Karen Steidinger, Rita Horner, and Carmelo Tomas.

States monitor their coastlines for blooms of toxic algae throughout the year, and the stakes are high. Missing a bloom can kill people. A false identification can have needless economic repercussions on seafood businesses. There are a lot of lives and money on the line when making these calls.

"It really takes the blending of the older, morphological techniques with the newer, molecular techniques to develop a profile in which you can have the highest confidence," Steidinger said. "One day, advanced molecular techniques may be able to stand on their own, but, at least for now, we really need to substantiate the molecular with the morphology."

The course was a mix of lectures, demonstrations, and hands-on time using microscopes to examine samples of harmful diatoms, flagellates, and dinoflagellates. The group focused primarily on dinoflagellates as they represent the majority of the algae strains responsible for problematic blooms in the United States. The visual differences between toxic and non-toxic strains of these algae are often extremely subtle, but they can be seen by a carefully trained eye.

Using these subtleties to successfully identify algae relies on a hierarchical taxonomy approach – a systematic series of questions that gradually narrows an alga’s identity. Is it armored with protective plates or is it unarmored? What is the pattern of the plates? What’s their shape? What’s their size?

Answering these spatial questions can be especially challenging because you first have to understand these microscopic organisms as three-dimensional objects. Toward the end of course, the instructors challenged the participants to make models of hazardous algae with clay. Golf ball-sized algae soon began to take shape as students molded the armor plates and carefully studied how they fit together.

"It’s fascinating that nature is so diverse, that something so small can have such a beautiful and intricate design," Steidinger said. "It still amazes me. Down to the smallest details, there are morphologic features that are miniscule but part of a pattern that’s absolutely beautiful."

The course’s 17 participants came from seven state agencies, three federal agencies, three native American tribes, three universities, and one oceanographic institute. While they came from diverse institutions, they are all professionals responsible for monitoring for harmful algal blooms and safeguarding human health.

"It was incredibly valuable to see how other states handle similar challenges," said Mark Vander Borgh, a course participant and algal ecologist with the North Carolina Division of Environmental Quality. "There’s a huge variety in the resources we have, the tools we use, and the policies we follow. I feel like we all left with a great network to rely on and ask questions of in the future."

The Digital Classroom: Zeiss, Bigelow Laboratory Test New Tools

This course on harmful algal blooms also provided a test bed for some new educational technology.

Zeiss donated the use of 18 networked microscopes for the course. This digital classroom setup wirelessly shared each microscope’s view, allowing the instructors to see through their students’ eyes. Using a dedicated app, they could monitor all students at once and quickly zoom into a particular view. This allowed the instructors to easily offer individual assistance or share students’ views on the classroom projector. The embedded cameras also allowed students to photograph samples and share images via the network.

"I’ve taught more than 22 courses and workshops, and this digital classroom setup has created a new paradigm," said Carmelo Tomas, one of the course instructors and professor emeritus at University of North Carolina Wilmington. "It was the most effective method I’ve used to date for delivering a one-on-one training experience to a group."