Oct. 25—EAGLE NEST — Pea-soup green pigment floated where the water met the shore on Eagle Nest Lake on Tuesday, while bright, turquoise pigment stained the south boat ramp. In the water, a flurry of blue-green algae drifted, like a collection of grass clippings.

Across the lake, Savannah Cutler waded into a thick algal bloom in knee-high gray boots. Wearing purple gloves to protect her hands, she dipped a small amber container into water topped by a slick of algae.

Cutler is a water resource professional with the New Mexico Environment Department’s Surface Water Quality Bureau. The sample she collected was destined for an Environmental Protection Agency lab to test for toxins.

As blue-green algae dies and begins to fall apart, it releases pigment and sometimes toxins, too. Those toxins can cause rashes, itching, numbness, fatigue, disorientation, abdominal pain, vomiting and diarrhea.

In extreme cases, they can cause death when ingested. No human deaths from harmful algal blooms have been reported in New Mexico, although a handful of dog deaths have been reported.

NMED is starting up a program this year to do more comprehensive water sampling for blue-green algae, also called cyanobacteria, and other types of harmful algal blooms, according to Lynette Guevara, program manager for the Monitoring Assessment and Standards Section of NMED’s Surface Water Quality Bureau. Harmful algal blooms are considered an emerging contaminant problem, she said, because there are still unknowns about the blooms and the toxins they produce.

NMED is working to find more definite information about when seasonally the state can expect harmful algal blooms and when in the year the blooms go away, said Miguel Montoya, team supervisor for the surface quality monitoring team. They seem to peak in late summer and early fall, Guevara said.

Cyanobacteria have been around for millennia, but the EPA began doing more research on blue-green algae and sending it to states in recent years. That increase in information is part of why New Mexico is increasing monitoring, according to Guevara. Two of the toxins produced by cyanobacteria were also added to the state’s water quality standards in its last Water Quality Triennial Review, another reason to increase monitoring.

Some big populations of cyanobacteria have popped up in the country over the last decade or so, like in Lake Erie in 2014 and Florida’s Lake Okeechobee in 2018, increasing public awareness of it, according to Barry Rosen, a Florida Gulf Coast University professor who specializes in cyanobacteria and algae.

It’s hard to say for sure if there are increases in harmful algal blooms in New Mexico, because there aren’t very many data sets over time, Guevara said. Although, she believes the low snowpack last winter caused lower water levels than normal and could be contributing to the number of harmful algal blooms this year.

“We initially started collecting data, a small data set, maybe two years ago, in a very limited number of lakes where we weren’t seeing these big issues,” Montoya said.

Nutrients like nitrogen and phosphorus can support blue-green algae, so nutrient control is one thing water managers can address. But some sources of nitrogen are outside of water managers’ control, Rosen said. Nutrients can come off of golf courses, sewage treatment plants and from agriculture production, and are naturally occurring.

Killing harmful algal blooms isn’t an option, Rosen said, because cyanobacteria are throughout bodies of water. Attempting to kill one part of the population could allow regrowth from other cyanobacteria. It would also kill off other types of algae that don’t produce toxins, potentially creating more opportunity for even more blue-green algae to flourish. Cyanobacteria can also be important to aquatic ecosystems.

There are an estimated 10,000 species of cyanobacteria, and very little genetic information about them, Rosen said.

“We don’t really know who is making what toxins,” he said.

The bright colors of blue-green algae help the state monitor it. NMED starts its monitoring in the office, with satellite images of lakes throughout the state. An app alerts them if the pigments in the water indicate the potential presence of harmful algal blooms. Then they send out a team to take water samples.

The Surface Water Quality Bureau also does annual surveys of different lakes in the state. This year, the surveys are of lakes in the Canadian River Basin. When staff are testing the water for toxic metals and other toxins, they’re also on the lookout for harmful algal blooms.

The public can play an important role in monitoring water quality at the state’s lakes too, by alerting the Surface Water Quality Bureau when they see potential algal blooms. Smaller lakes in the state aren’t included in the satellite monitoring, but NMED discovered Quemado Lake in western New Mexico had harmful algal blooms after photos were posted on social media, said Montoya. On Friday, NMED warned visitors to Quemado Lake not to swim in the water and to keep pets away after water samples confirmed the presence of harmful algae and toxins.

The agency issued a health warning for Clayton Lake earlier this month because it also tested positive for toxins. NMED has issued advisories about the presence of harmful algal blooms at six other lakes in the state: Snow, Hopewell, Charette, Maloya, Santa Cruz and Eagle Nest.

Updated advisories and warnings can be found on the NMED harmful algal bloom website: https://www.env.nm.gov/surface-water-quality/habs.