Joanna Hamer | Staff Writer
Every other weekend, at an hour when most Chautauquans are eating breakfast or attending worship services, two boats set out onto Chautauqua Lake.
In the northern basin, Jane Conroe steers her motorboat away from shore. In the southern basin, Jeff Moore winds down the winch for his small rowboat and sets a course for the center of the lake.
Moore has with him a box of equipment — bottles, a thermometer, a clipboard and pencil. When he gets to a point in the lake marked by a nearby outcropping, he puts down the anchor and pulls in the oars. He takes from the crate a Secchi disc, a circular device cut into quarters of alternating black and white. He drops it on a cord into the lake, marking the depth at which he can no longer see its outline.
Once he hauls the Secchi disc in, Moore sends down a sample bottle, holding its rope straight so that when it descends to a meter and a half, he can drop the lid directly onto the container. He records the air temperature and water temperature, writing down comments about the weather.
He rows back to shore, winches up his boat and puts the water sample in his fridge, next to his sodas, to be sent along with Conroe’s sample to a New York State Department of Environmental Conservation lab for further testing.
Both Conroe and Moore are volunteers working with a program called CSLAP, or Citizens Statewide Lake Assessment Program. The tests performed on their samples are analyzed at the DEC to draft recommendations for protecting Chautauqua Lake’s health, which is in danger because of certain human activities.
The program is a step toward better understanding the lake’s problems — including weeds, algae blooms and chemical level fluctuations — and the causes and interrelations of those issues.
Making the measurements
CSLAP is a volunteer program conducted jointly by the DEC and the New York State Federation of Lake Associations, or NYSFOLA. The Chautauqua Lake Association began the program and pays the DEC an annual lab fee.
Conroe has worked with CSLAP in Chautauqua Lake since the first boat set out to sample the water in 1987. Moore joined five years ago, when he moved back to the area after finishing his service with the U.S. Navy.
“We were on the lake, and we knew this wouldn’t hurt,” Conroe said. “I don’t think we ever realized that it would be going on this long.”
Under the program, Conroe and Moore receive a package in the spring containing sample bottles and observation records, which they fill twice a month and mail to a lab in Syracuse, N.Y. The lab analyzes the samples and returns the results in a state-certified report, which is also shared with the Chautauqua County Department of Health.
Scott Kishbaugh, chief of the Lakes Monitoring and Assessment Section of the DEC’s Bureau of Water Assessment and Management, reviews the data about the water samples.
“They are analyzed for a standard suite of water-quality indicators that are the same in all of the 110 lakes in the program,” Kishbaugh said. “It’s primarily what’s referred to as a eutrification-based program, meaning the kinds of things that turn the water green.”
The trophic state index — either oligotrophic, mesotrophic, or eutrophic — is a measurement of biological activity in water based on chlorophyll a levels, phosphorus content and clarity of water, as measured by Secchi disc. Oligotrophic water bodies have very low nutrients and algae and therefore are very clear and highly oxygenated. Mesotrophic lakes have medium productivity, with some submerged plant life, and eutrophic lakes contain highly nutrient-rich water that is home to abundant plants and algae.
Chautauqua Lake hovers between mesotrophic and eutrophic categorizations, depending on seasonal nutrient content and aquatic life.
An impaired lake
In 2002, Chautauqua Lake was declared impaired under the Clean Water Act because of its high-nutrient content, caused largely by phosphorus in rainwater runoff.
“In the north basin, over the 25 years or so that we’ve been monitoring, we’ve seen a slight increase in the phosphorus concentration in the lake,” Kishbaugh said. “We haven’t seen that same trend in the southern basin. One of the reasons may be that the southern basin of the lake already has a higher phosphorus concentration than the northern basin does.”
The 2010, CSLAP report also showed an elevated level of deep-water manganese, a slightly raised pH and slightly higher than normal water temperatures in the northern basin, which is much deeper than the southern.
“We’ve also seen a slight increase in color levels in the northern end of the lake,” Kishbaugh said. “The natural color of both of the basins of Chautauqua Lake are relatively low, but they’re increasing slightly in the northern basin.”
Water color can be turned green by algae or brown by other organic matter. The rest of the water quality tests conducted on Chautauqua’s waters — for conductivity and metal content — showed no significant change.
Problems old and new
“I don’t think the trends are as alarming as people might think they are or want to believe they are,” said Doug Conroe, director of operations at Chautauqua Institution. “The lake’s been in trouble for a lot of years. It’s just now that people are getting more aware. As we experience climate change differences, it accentuates events.”
Conroe deals with lake health frequently, overseeing storm water runoff management projects and monitoring the level of lake weeds.
“We’re always going to have nuisance plant growth. Some of the nuisance plant growth that we’re experiencing today is really no different from what was experienced 100 years ago,” he said.
Native plants such as elodea, Conroe said, benefit the ecosystem and have been present for thousands of years.
But some of Chautauqua Lake’s vegetation is different — and new. Particularly troublesome is the invasive Eurasian milfoil, whose slimy clutches are familiar to lake swimmers and boaters. The Institution contracts the Chautauqua Lake Association to harvest the weeds three times per week, and the Gardens and Landscaping staff compost their remains. But it is not a winnable battle; when the milfoil is cut up into fragments, each piece can grow into a new plant.
Eurasian milfoil is a voracious plant that often crowds out native species, but it also has benefits. Fish need lake vegetation as a spawning area for their young, and birds, bugs and moths consider the plants food sources. And surprisingly, the milfoil may help to keep down harmful blue-green algae blooms. But excess weeds choke up water sources, causing problems for lake inhabitants, swimmers and boaters.
Milfoil produces allelopathic compounds which are not essential to its survival but instead targeted to inhibit the growth of other organisms, including algae. The plant also provides safe nurseries for many small invertebrates who consume algae. Those efforts help to dampen algae blooms, but clearly the milfoil cannot completely deter the issue.
“The water chemistry is at the point of saturation,” Conroe said. “The lake is at the tipping point level where it just takes a little bit more and bingo, you’ve got blue-green toxic algae that you didn’t have before.”
The lake now contains so many nutrients, including the estimated 9,900 kilograms of phosphorus flushed into it each year, that it takes only the heat of the summer months to grow the blooms.
The blue-green algae blooms are not actually algae. They are cyanobacteria, a green-colored microbe that performs photosynthesis the same way green plants do. Scientists believe that chloroplasts in vegetation evolved from cyanobacteria that were engulfed and incorporated into plant DNA millenia ago.
“The algae bloom is not a bad thing,” Doug Conroe said. “It’s certainly undesirable to people who want to swim in the lake or drink the water, but it’s a natural thing.”
Chautauqua Lake, which is tens of thousands of years old, has always had algae and cyanobacteria living in symbiosis with fish and microplankton. But the current nutrient overload generates the blooms earlier and with more intensity.
“Algae blooms are OK unless they’re overabundant,” he said. “When they bloom, their composition changes from normal to toxic.”
Cyanobacteria, when given the right conditions and nutrients, reproduce exponentially and explosively, and certain strains begin to produce toxins. Those dangerous compounds can affect the liver and brain, though scientists say more studies are necessary to determine the extent of the danger.
“We have, at this point, a growing base of information about algal blooms — what causes them, what triggers them,” Kishbaugh said. “We understand that there’s a relationship between nutrients and algae blooms, but the specific trigger point is probably pretty complicated.”
Factors such as water flow, temperature, exact nutrient composition and competition from or consumption by other organisms all combine to create the conditions for a harmful blue-green algal bloom, though the specific combination necessary is still unknown. The unusual spring season, however, has raised questions.
“This year has been quite hot and dry,” Kishbaugh said. “We’ve seen a greater reporting of blooms this year, but it’s difficult to say whether or not that’s because more people are looking for them or if more blooms are actually occurring.”
The year’s abnormal pattern of drought and torrential rain has also had an effect.
“It’s a little warmer, this spring we’ve had; the storm pattern has changed. We’re getting some bigger storms that flush out the watershed more than smaller storms,” Doug Conroe said.
“The fact that it hasn’t rained, that we’ve had a drought, has probably postponed the bloom,” Jane Conroe said. “In a regular summer, it takes the heat, so it’s usually August.”
Apart from the algal blooms, another element — or perhaps several elements — attracts the DEC’s attention. Because Chautauqua Lake’s northern basin is so deep, the water is thermally stratified into different sections according to depth. The deepest segment of cold water mixes poorly with the rest of the lake and can harbor dangerous chemicals.
“If the oxygen runs out in the bottom of the lake, which can occur both naturally and unnaturally, the bottom waters can be elevated in certain water quality indicators, some of which can cause problems,” Kishbaugh said.
Microorganisms that consume oxygen in their metabolic process break down organic matter, such as milfoil, that sinks to the bottom of the lake. Because the deep water does not cycle through the rest of the lake, there is no chance to replenish the oxygen content of the water. The microbes begin to metabolize anaerobically, which releases certain compounds from the bottom sediments.
Some of those elements, such as iron and manganese, affect only the taste of drinking water. But others, such as phosphorus, stimulate algae growth, and some, such as arsenic, pose health dangers. The lake mud contains low arsenic levels from natural deposits and from weed pesticides sprayed more than 50 years ago that have sunk to the bottom.
“That’s what they’re supposed to do — they’re supposed to sink to the mud and stay there,” Jane Conroe said. “But when (Kishbaugh) saw that the phosphorus levels were too high, he knew that the arsenic was going to be redissolved and redistributed to the water column.”
Between half and two-thirds of the lakes CSLAP monitors show signs of deep-water oxygen deficits, Kishbaugh said, caused by a combination of geomorphic conditions and geographic location. At the moment, there is no cause to worry about arsenic in Chautauqua Lake — the amount in the samples Moore and Conroe have collected is well below the maximum contaminant level.
Spreading the word
“We’re still trying to understand how all of these things are interrelated,” Kishbaugh said. “And the more monitoring information that you get, the more surveillance that’s out there, the more likely it is that we’re going to be able to start to understand all of these interconnected factors and build management plans.”
Kishbaugh said providing outreach and education to the public about lake concerns is essential. People should know what to look for and be mindful of the impact of individual activities on the lake’s health.
Progress comes from more funding, stricter laws about pesticides, programs such as CSLAP and actions taken by lakeside property owners such as the Institution.
“It gets down to nutrient managing,” Doug Conroe said. “You keep them from getting into the lake. You look at what discharges into the lake. You add an additional treatment to your sewer plant. How do you deal with runoff from the land? Buffer zones and trees. We need more trees, especially on the lakefront.”
The Institution has put great effort into containing its runoff, using rain gardens and porous surfaces to keep rainwater from reaching the lake. In Chautauqua County, 2 percent of the 5 percent occupancy tax goes toward waterway improvement, and the CLA has received a total of $100,000 this year to harvest weeds.
Concern for the lake also grows on the grounds. Many people have attended a Special Studies class and Lake Walks hosted by Jane Conroe and Deb Naylor, who are both conservationists for the Chautauqua Watershed Conservancy.
The Special Studies class, “Water: Possibly the World’s Most Valuable Resource,” happened during Week Four, themed “Water Matters,” and included testing and purifying water.
The Special Studies catalogue advertised that “Chautauqua Lake will be used as a model for world-wide water issues.” And the Lake Walk provided an opportunity for children and adults to perform simple chemical tests on lake water.
“That citizen science, that awareness — you could definitely take the kit and test the creek in your own backyard,” Jane Conroe said. “And that would be a good thing.”
Kishbaugh praised the efforts of the CLA, CSLAP volunteers and the Chautauqua County Department of Health in offering information to people, but reiterated that a healthy lake requires the efforts of the whole community.
“When the public identifies an area that they’re concerned about, something they see or read about, it’s important to contact one of the local experts,” Kishbaugh said, “because they’re really on top of a lot of the key issues that are going on and they can provide good guidance to people about how they should proceed.”
Moore and the Conroes will keep monitoring the lake until the end of the summer, and the DEC and DOH will continue to collaborate with local organizations to study and improve the lake’s health.
When Moore docked his boat at his jetty after collecting samples, he remarked the entire area around the lake used to be swampland before being developed for housing. In high school, he volunteered with the CLA, and welcomes the opportunity to help again on his return.
Moore and his neighbors grow trees and shrubs around their shared lake access, helping to anchor the soil and prevent phosphorus being swept into the lake in runoff. He doesn’t think they ruin his lake view.