Third-Party Report: Radical Detrimental Changes in Chautauqua Lake

Algal bloom, Chautauqua Lake 2019
Photo by Racine-Johnson Aquatic Ecologist from October 1, 2019. Cyanobacteria (blue green algae) or harmful algae blooms (HABs) dominated the south-east end of the south basin, including Burtis Bay, Elmhurst and Sunnyside

Dearth of aquatic plants in south basin leads to dangerous algal blooms, habitat loss

LAKEWOOD, NY Jan. 6, 2020 – A third-party’s 2019 fall survey of the habitat of Chautauqua Lake, a waterway that supports a rich economy based on sports fishing, recreation, vacation rentals and tourism, found the lake’s status had “skewed radically from the norm,” essentially creating two lakes, a vibrant, normal one north, and a barren, vulnerable one south.

A 158-page report from the independent and well-respected Racine-Johnson Aquatic Ecologists of Ithaca, NY states in unusually stark language for a scientific paper the changes observed. It documents how Chautauqua Lake exists in two extreme parts, with the south basin a barren lake floor where “data shows critical decline from a healthy sustainable littoral ecosystem;” and the north basin, where aquatic plants continue to grow well, buffering against dangerous algal blooms witnessed in the south basin last summer.

“Our late-summer/early-fall 2019 plant survey results came as a shock, and should alarm the stakeholders of Chautauqua Lake,” states the annual report prepared independently for the Chautauqua Lake Association. The report uses “macrophytes” as a scientific term for aquatic plants in the lake, where 27 species were found, none of them newly invasive.

“The outcomes we normally expect, after 18 years of consecutively collecting variable aquatic plant and invertebrate community data from Chautauqua Lake, skewed radically from the norm,” the report’s authors wrote. “The submersed aquatic plant growth in the north basin, north of Long Point, was normal and anticipated for a fall survey, generally good-to-excellent water clarity and a healthy growth of desirable macrophytes. South of Long Point, blooms of phytoplankton were obvious and did not dissipate during our survey.”

The survey, from Sept. 17 to Oct. 1, 2019 generally involved the rake-toss method of collecting plants to determine density and variety. The New York State Department of Environmental Conservation recently issued bid invitations for a three-year state project requiring use of the same certified approach, which involves gathering plants from the lakebed and analyzing their health and frequency.

What caused this radical change in the lake’s south basin? In spring of 2019, the herbicides 2,4-D and endothall were applied in near-shore areas south of Long Point. The report concludes these herbicides were highly effective, doing their job of killing nearly all plant life in those areas. But the report states that such removal is “detrimental to the health of the lake’s ecosystem.” The survey also found the herbicides killed well beyond a specific application zone, due to inevitable drift of the chemicals in the water column.

“The stakeholders of the lake may, or may not know, or recognize, what happened to Chautauqua Lake south of Long Point in 2019,” the report says. “The stakeholders that fish in the lake, who spend time at the shoreline or in a boat, have noticed that the summer months in the south basin, in 2019, were not the usual. However, this fall other stakeholders accepted the news reports, internet posts and a third-party report that the management of aquatic macrophytes by the application of aquatic herbicides, south of Long Point, on Chautauqua Lake in 2019, was a success and beneficial.”

“We agree, the application of the herbicides 2,4-D and endothall on May 15-17, 2019 was successful in removing macrophytes from large areas of the lake’s littoral zone (where plants grow). Conversely,
we do not agree that this almost total plant removal in those areas was beneficial, but rather it was detrimental to the health of the lake’s ecosystem.”

“The management decision to prohibit herbicide use north of Long Point in 2019 was astute and that decision must remain,” the report concludes.

The annual survey, according to the report, found few plants in the south basin, concluding that: “A decrease in macrophyte species diversity, richness and biomass has the potential of leading to a decline of a world-class, warm-water fishery dependent on the habitat that aquatic plants provide.”

“Since 2002, we have recorded for 17 years in the south-east end of Chautauqua Lake aquatic plants and macroinvertebrates as part of a vibrant lake ecosystem, while in the 18th year our data shows large areas in critical decline from a healthy sustainable littoral ecosystem,” the Racine-Johnson ecologists wrote.

In addition, since the herbicides were applied to water, its fluidity distributed them beyond the areas permitted for treatment, the report found. This finding, therefore, “clearly suggests the drift and concentration of 2,4-D was vast and basin-wide, likely contributing to the massive indiscriminate defoliation of the macrophytes in the south basin.”

“The wholesale loss of macrophytes may push the south basin toward a phytoplankton-dominated turbid state, void of many of the submersed plants, invertebrates and fish that have inhabited this
littoral zone historically,” the scientists continued. “While the south basin could recover quickly, it is likely to be a slow return to normal macrophyte growth with HABs [harmful algal blooms] currently having the advantage.”

According to the National Oceanic and Atmospheric Administration, harmful algal blooms, or HABs, occur when colonies of algae – simple plants that live in the sea and freshwater – grow out of control and produce toxic or harmful effects on people, fish, shellfish, marine mammals and birds. “The human illnesses caused by HABs, though rare, can be debilitating or even fatal,” the agency states.

Among the report’s additional conclusions:

  • The importance of having a robust healthy macrophyte community in the littoral zone of Chautauqua Lake is essential to the survival of this large, shallow lake. A decrease in macrophyte species diversity, richness and biomass [have] the potential of leading to a decline of a world class, warm water fishery dependent on the habitat that aquatic plants provide. Loss of macrophytes from the littoral zone in a large eutrophic shallow lake, like Chautauqua, will dramatically increase nutrient loading and shoreline erosion into the water column by allowing an increase in wind driven waves to whip up the bottom sediments and pound the shoreline. The loss of plant structure that provided refuge for the phytoplankton grazing zooplankton from planktivorous fish can lead to a zooplankton decline allowing phytoplankton and cyanobacteria to increase.
  • Therefore, conservation of these essential biological control agents is paramount in maintaining a healthy Chautauqua Lake. Protection from the wholesale elimination of macrophyte species from the littoral areas must be the top consideration in the long-term management of the lake. With the loss of macrophytes from large sections of the south basin, those areas will likely experience a decline of macroinvertebrates, the fishery and water clarity along with increased phytoplankton blooms and corresponding low oxygen levels. The management decision to prohibit herbicide use north of Long Point in 2019 was astute and that decision must remain. Prohibiting herbicide usage in crucial fish habitat specifically used for spawning and nursery is paramount as suggested at an earlier time in areas like Tom’s Point, Whitney Bay and Irwin’s Bay. The decision in 2020 for managers and stakeholders of Chautauqua Lake is how to improve the lake ecosystem south of Long Point while continuing protection to the north.

Racine-Johnson Aquatic Ecologists of Ithaca, NY, was formed by Robert Johnson upon his retirement as Cornell University’s Cornell Ponds Manager. Johnson has been monitoring aquatic plants and herbivores in Chautauqua Lake annually since 2002 under contract to the Chautauqua Lake Association as an independent monitor. Racine-Johnson also performs third-party consultant herbicide-monitoring for NYSDEC and other lake associations.

The Chautauqua Lake Association traces its beginnings to 1946 and its actual formation in 1953. The current focus is to perform environmentally sound plant-control practices, undertake scientific monitoring and relevant research, service the shoreline in promotion of maintaining healthy conditions, and promote educational efforts to enhance public understanding of lake association methods and lake needs. Since 1954, the CLA has sponsored lake improvement projects, has performed lake maintenance services, and has facilitated on-going scientific monitoring and research. The CLA is a charter member of New York State Federation of Lake Associations (NYSFOLA). For more information, visit

State Bid Request Reinforces Use of “Johnson” Plant Analysis Method

Surveying process Chautauqua Lake Association uses backed by state bid specifications

The following is from a news release from the Chautauqua Lake Association. Douglas Conroe is the Executive Director.

LAKEWOOD, NY December 2, 2019 – The New York State Department of Environmental Conservation (DEC) recently issued bid invitations for a three-year, state project that requires that an aquatic plant-surveying method used for almost two decades to assess Chautauqua Lake is utilized for the state project.

This bid process reinforces the scientific value and relevance of the so-called Johnson method of testing plant density and variety. The method is named for Robert Johnson, who started his work for the Chautauqua Lake Association (CLA) in 2002 in his role as Cornell Ponds Manager. He has since retired from Cornell and is now a principal with Racine-Johnson Aquatic Ecologists of Ithaca, NY.

“Robert Johnson has performed aquatic plant species and density monitoring services for the CLA since 2002,” said Chautauqua Lake Association Board of Directors President Paul O. Stage. “His surveying has uniformly utilized a rake-toss method that produced a valuable historical database from which plant-management decisions have been guided. We are very encouraged that the DEC is recognizing the value of his work and has endorsed his method for use statewide.”

The rake-toss method, which is surprisingly not utilized by some parties involved in Chautauqua Lake assessments, is now known as the Point Intercept-Rake Drag with Plant Species Percentages Method. More about the process and its results are available in the Racine-Johnson reports posted on the CLA’s website,

Johnson is a member and former president of the Northeast Aquatic Plant Management Society, and served on its board of directors and as editor of its newsletter for several years. He received the highest professional award from the plant society, the Aquatic Plant Science Award, in 2005 and in 2017. It recognized his scientific contributions to understanding the ecology of the non-native invasive species Eurasian watermilfoil and Hydrilla.

 “We appreciate having Bob Johnson’s independent plant-monitoring services available to the lake,” said CLA Executive Director Douglas Conroe. “He is providing us with valuable data about Chautauqua Lake’s rich species-diverse aquatic plant community. Chautauqua Lake continues to be an environmental treasure for the community, which his data evidences. The DEC’s endorsement of his utilized-plant surveying method simply reinforces the value of his work.”

Racine-Johnson also performs third-party consultant herbicide-monitoring programs for the DEC and other lake associations. Johnson played a long-term, third-party role in evaluating SOLitude Lake Management’s herbicide treatments for Lamoka/Wanita Lakes near Tyrone, NY for 17 years and Cazenovia Lake for 11 years. He also is the lead scientist for the local and state efforts to halt the spread of the growth of the non-native invasive Hydrilla verticillata discovered on August 5, 2011 in the Cayuga Inlet of southern Cayuga Lake at Ithaca.

More about the Chautauqua Lake Association

The Chautauqua Lake Association, a non-profit 501(c)3 corporation, is the only organization carrying out actual lake maintenance work. Its all-volunteer Board of Directors is made up of men and women from all walks of life. Involving the collaboration of volunteers, businesses, individuals, governments, and foundations the CLA can perform operations at a cost that has proven to be the least expensive option for lake maintenance services.