Saturday, July 8, 2017

N.Y. / REGION

Beware the Blooms: Toxic Algae Found in Some City Ponds

By LISA W. FODERARO
A sign warned of an algae bloom in the Lake in Central Park, advising to keep animals away and not to drink from, wade in or fish in the water. Sam Hodgson for The New York Times
The VanderGast sisters were admiring the turtles paddling through the Lake in Central Park under a blazing sun the other afternoon.
“If one swam up to me, I was going to wade in and try to hold it,” said Zoe, 15. Her sister, Anna, 13, took one look at the strange greenish tint — a color reminiscent of green antifreeze — and grimaced. “The water looks pretty nasty,” Anna said.
Summer is here, and the lakes and ponds that dot the city’s parks are awash in algae. Much of it is just unsightly. But some types, like the blue-green algae in the Lake in the southern half of Central Park, can be harmful, causing rashes on people and posing a lethal risk to dogs.
Blue-green algae can be hard to see. Its hallmark is a uniform green hue, sometimes with large swirls — as if someone spilled pale green paint on the darker green surface.
There is no simple fix for blue-green algae, also known as cyanobacteria, which is caused by an excess of nutrients like phosphorous and nitrogen in the water. In most parts of the country, those nutrients result from storm water and agricultural runoff, fertilizers, dog waste and nearby septic tanks.
In some New York City parks, however, their presence may be traced to the city’s municipal water supply, which feeds a number of water bodies. Since the early 1990s, the Environmental Protection Agency has required cities to add orthophosphate to drinking water to reduce the incidence of lead poisoning from old pipes.
The greatest risk from blue-green algae is to dogs, since the toxins can affect the liver and neurological system if ingested. Sam Hodgson for The New York Times
As soon as tests reveal the presence of cyanobacteria, park officials post signs, like the ones seen around the Lake in Central Park this week under the heading, “Algae Bloom Advisory.” It cautions visitors not to drink, wade or fish in the water and urges that animals and children be kept away.
The New York State Department of Environmental Conservation has tracked the presence of so-called harmful algal blooms since 2012, and this year, the season is off to a robust start. Each week, the department’s websiteupdates a list of sites statewide with suspicious or confirmed blooms. It now includes 30 lakes and ponds. “By August, we usually have 70 to 80 ponds and lakes on the list,” said Rebecca Gorney, a research scientist for the department, which has no oversight of New York City parks.
Only the Lake in Central Park and the Prospect Park Lake in Brooklyn are listed as “confirmed with high toxins,” meaning that water samples collected there have toxins in large enough quantities to cause health effects in people and animals.
Officials at the state agency have noted a rise in the number of sites in recent years, but it is unclear whether that is because of more awareness and reporting, or an actual increase in blue-green algae. Reducing the sources of nutrients, such as runoff, along with chemical treatment and aerators, are some of the tools that lake managers are trying around the state.
The presence of phosphate in the water source of the lakes in New York City parks has limited the options for addressing blue-green algae. But in Prospect Park, where the 60-acre artificial lake is fed by a mile-long water course, including four man-made waterfalls, park officials are poised to try something new. The source of the nutrients bedeviling the lake is a 12-inch-wide pipe connected to the municipal water supply at the uppermost waterfall.
The Prospect Park Alliance, a nonprofit group that helps manage the park, just received a $390,000 grant from the state to pursue a pilot project that will filter out phosphate from the headwaters of the water course. The project, now in the initial planning stages, will use plants rooted in underwater containers adjacent to one of the top falls.
It’s like putting the water through a giant Brita filter but with plant material instead,” said Christian Zimmerman, vice president of capital and landscape management for the Prospect Park Alliance, which received the grant from the state’s Office of Parks, Recreation and Historic Preservation. “It draws up phosphates from the water and after a certain amount of time, a baffle opens and the water gets released back into the upper pool.”
Mr. Zimmerman said that he hoped the pilot project, if successful, could be replicated in urban parks nationwide. “Everyone has a problem of nutrients in the lake,” he said. “This is national. Nobody wants a green lake.”
The greatest risk from blue-green algae is to dogs, because they are more likely to drink the water and the toxins can affect the animal’s liver and neurological system if ingested. Licking fur that has come in contact with cyanobacteria can be dangerous as well.
Dr. Vanessa Hammer, a veterinarian with the Gotham Veterinary Center on Manhattan’s Upper West Side, said that a dog owner brought in his pet two weeks ago, frantically worried that he was exposed to blue-green algae. The dog had swum in another of Central Park’s ponds, but only the Lake currently contains the harmful algae in bloom quantities.
“The dog was fine,” Dr. Hammer said. “But in general, the toxins in blue-green algae can cause severe neurological symptoms that can lead to death within a couple of hours.”
The Central Park Conservancy, the nonprofit group that manages the park for the city, collects weekly samples from the Harlem Meer, the Pool, Turtle Pond and the Lake. The samples are sent to a lab and depending on the results, the city’s parks department then makes recommendations about signage.
In Central Park on Thursday, Myung-Hi Kim was walking her dog, Nika, along the southern shore of the Lake. “She tries to go near it, but I always pull her away,” she said. “I’m a true west sider so I know about the dangers of algae blooms.”
Posted by at No comments:

Why Do Algae Grow in Ponds in Warm Weather?

By C. CLAIBORNE RAY
Victoria Roberts
Q. Why do algae grow in ponds in warm weather? Are they the same algae from year to year or does a new batch grow every year?
A. The usual suspects in the growth of pond scum are not common algae, of which there are many kinds, but a kind of microorganism once called blue-green algae and now usually referred to as cyanobacteria, because they are more like bacteria in structure. Cyanobacteria are normally unobtrusive year-round residents of puddles, ponds and lakes and usually do not make themselves known until they undergo a spurt of abnormal population growth called a bloom, producing visible scum.
Enormous blooms have clogged lakes and waterways from Florida to China. Normally, though, small blooms die off after a week or so. The factors leading to a bloom are not fully understood, but are believed to include at least intermittent exposure to bright sunlight and warm temperatures; calm, cloudy water; and an enriched supply of nutrients, notably phosphorus and nitrogen.
Summer brings increased sunlight, which powers the photosynthesis the cyanobacteria use to make their own food. When light and temperature drop off in the fall, so does the growth of cyanobacteria. No one factor predicts a bloom, but an excess of nutrients from sources like runoff from fertilized agricultural land and sewage is assumed to be a major contributor and is a likely target for human control efforts. Control of large-scale blooms is a priority, because some products of cyanobacteria, released when the cells die, are potentially poisonous to people and animals. 
Posted by at No comments:

A Dreaded Forecast for Our Times: Algae, and Lots of It

By MATT RICHTEL
A satellite image showing an algal bloom that caused a temporary ban on using tap water in Toledo, Ohio, in 2014. National Oceanic and Atmospheric Administration
Every Thursday night, Bill Korbel, a veteran meteorologist, offers his standard weather forecast to viewers on a Long Island cable channel. Then he follows up with his outlook for toxic algae.
On a map, Mr. Korbel points out areas with high concentrations of algae — natural gatherings of microscopic plankton that, while often innocuous, can degrade water quality and even be dangerous.
“Brown or red tide is much catchier than harmful algal bloom,” Mr. Korbel joked about the right wording to use in his broadcast. It’s a relatively new topic for him, something that was never part of his decades-long career. Nor was it part, he said, of his meteorology training at New York University. “That was down the hall, in oceanography,” he said.
Mr. Korbel may not be an outlier for long. If a growing number of scientists have their way — and can get federal funding they say is desperately need to protect the public — algae forecasts could become as common as weather reports, and as essential.




Toledo, Ohio, had to temporarily ban the use of tap water two years ago when toxic algae bloomed in Lake Erie, for example, and California authorities advised people to avoid eating certain crabs contaminated by algae. Nationwide, the health and economic costs from harmful blooms are estimated at $82 million a year, according to the federal government.
Sophisticated sensors can be deployed to measure when toxins are reaching harmful levels, allowing officials to redirect fishing, beachgoers or water treatment efforts.
In 2014, Congress reauthorized the Harmful Algal Bloom and Hypoxia Research and Control Act, originally passed in 1998, to encourage more research. But the measure didn’t actually provide funding; it only signaled the need for it.
So money for algal bloom science comes from more general federal science funds, and those pots are shrinking. Congressionally approved funding for a broad range of related science is around $9 million this year, down 45 percent from five years ago, according to several scientists involved in the research. That means less money for deploying sensors or even to pay for boats and crews to monitor the shorelines.
“It’s a paradox,” said Christopher Gobler, a professor of marine sciences at Stony Brook University who provides the data for Mr. Korbel’s weekly report and believes the field should be more mainstream. “We need it more than ever, and we’ve brought ourselves to the precipice of making great forecasts, but we can’t make it happen.”
Dr. Gobler and his team do their sampling the old-fashioned way — by fanning out on Mondays around Long Island and scooping up water samples. His project is financed largely by foundations.

Evelyn Lessard, a professor of oceanography at the University of Washington, has faced steep challenges in trying to do more advanced forecasting. Eighteen months ago, the National Science Foundation helped her acquire a $135,000 sensor that sucks in water, takes photographs and transmits them to researchers, who can identify algae that may be toxic.
Such a sensor can be a lifesaver, as it was in 2008 when an early version of the technology in the Gulf of Mexico picked up signs of a toxin that led to a monthlong shutdown of shellfish harvesting off the Texas coast, and a recall of mussels, clams and oysters.
In the case of Dr. Lessard, though, the grant money for the sensor was not enough to cover the cost of training to use it, and of deploying it off San Juan Island, Wash.
She wrote two proposals for funding — about $125,000 for two years — to the National Oceanographic and Atmospheric Administration, which has said that bloom forecasts are a priority for the agency. Both grant applications from Dr. Lessard were given high marks by NOAA reviewers, but there was no money to support them, and the sensor remains warehoused in Massachusetts. “It’ll sit on a lab bench,” she said.
Scientists say at least 20 sensors are needed around the country at a cost of about $7 million, including training and deployment. The only sensors now in use for any extended period, they say, are in the Gulf of Mexico, though the funding for those is scheduled to run out in 2018.
Vera Trainer, a NOAA scientist in Seattle who studies algal blooms, had to ask for volunteers to go on a research expedition to study algal concentrations in the Pacific Ocean because she did not have the money to send her own staff.
“I feel like a beggar,” she said.
“It’s not just robots that we need,” Dr. Trainer added. “We need the research that helps us understand the hot spots, when the cells are most toxic, in what years they’re going to be most intense, the effects of climate change.
“Without the basic knowledge, we have no forecast.”
President Obama’s 2016 fiscal-year budget called for $13 million for research related to harmful algal blooms.
“Unfortunately, there has been an increase in the number, frequency and type of algal blooms,” 19 House Democrats wrote in a letter late last year to ranking members of the House Appropriations Committee, in a failed effort to have the funding level met. The increase in blooms, the letter stated, “is having a crippling effect on local and regional economies.”
“Congress has been asleep at the switch for a long time,” Glen Spain, the Northwest regional director of the Pacific Coast Federation of Fishermen’s Associations, a commercial fishing trade group, said in a phone interview.
Mr. Spain said the early warning systems could help fishermen avoid millions of dollars in losses like those they suffered last year when toxic blooms devastated the West Coast crab season.
“We can’t live in a world where we don’t know what’s going on and we don’t know what to expect,” he said. “The more advanced notice, the better we know what to do.”

Posted by at No comments:
Subscribe to: Posts (Atom)