Racine-Johnson Aquatic Ecologists Memo to Stakeholders of Chautauqua Lake

Muskellunge (Esox masquinongy)
Muskellunge (Esox masquinongy)

This memo was distributed via email by Chautauqua Lake and Watershed Management Alliance, and is available online in PDF format.

Date: March 24, 2020

From: Robert L. Johnson: Researcher and Owner of Racine-Johnson Aquatic Ecologists 

To: Chautauqua Lake & Watershed Management Alliance & Stakeholders of Chautauqua Lake

Re: Racine-Johnson Aquatic Ecologists’ Research at Chautauqua Lake on the Aquatic Plant Community Ecosystem and the 2019 Spring and Late Summer/Early Fall Plant Survey Reports

The Racine-Johnson Aquatic Ecologists is a consulting company that collected scientific data on Chautauqua Lake in 2019 for the 18th consecutive year, which focuses on submersed aquatic vegetation and the associated ecosystem. As a researcher, I (Bob Johnson) began collecting scientific data on the aquatic plants and correlated insect herbivores at Chautauqua Lake first at Cornell University in 2002-2008, then continuing with Racine-Johnson Aquatic Ecologists from 2008 to the present. Beginning in 1966 at Cornell, my freshwater research informed NYS stakeholders: individuals, lake associations, and local and state governments about the importance of aquatic plant ecosystems. This included the management of excessive plant growth, when appropriate.

Additionally, my research focused on using common methods of plant control that included mechanical harvesting, bottom barriers, shading, and herbicides. All methods employed were consistent with sound methodology for aquatic research, and included extensive experience with old herbicide chemistries 2,4-D (1959) and endothall (1960).

My current research also includes studying the biology of Hydrilla verticillata a new plant invader in Upstate NY since 2011, and evaluates herbicides and other methods to eradicate the species in NYS. My research findings on insect herbivores that feed on the non-native plant Eurasian watermilfoil, which limits the plant’s growth, has worldwide recognition by the scientific community. Today, Racine-Johnson Aquatic Ecologists continue to study these herbivores as biological control agents on Chautauqua Lake, and other NYS lakes. Racine-Johnson has 18 years’ experience conducting scientific research at Chautauqua Lake on behalf of my sponsor, the Chautauqua Lake Association, which benefits stakeholders: the property owners, community members, fishing groups, and visitors.

Racine-Johnson’s ongoing research on Chautauqua Lake is multi-faceted, but it primarily documents the presence and density of submersed aquatic plants (macrophytes) in the lake. For 18 years, through yearly annual research reports along with public presentations and “hands-on” workshops to diverse groups about this large shallow lake, Racine-Johnson has long-advocated that a robust aquatic macrophyte community in Chautauqua Lake is desirable and essential to a healthy vibrant lake. Importantly, this “world-class” warm water, multi-species fishery requires a flourishing aquatic plant community.

Racine-Johnson Aquatic Ecologists have emphasized that excessive phytoplankton (algae) blooms are a much greater threat to the viability of freshwater ecosystems than thick macrophyte beds. Chautauqua Lake has phytoplankton blooms including cyanobacteria, which are an important part of its ecosystem. In 2008, Racine-Johnson conducted a lake-wide study describing phytoplankton species and concentrations. Racine-Johnson’s long-term aquatic plant data sets of Chautauqua Lake indicate that it has a relatively stable freshwater ecosystem because of the macrophyte growth in the littoral zone (area where rooted plants can grow).

In presentations at Chautauqua Institution in the last two years, Racine-Johnson emphasized the critical importance of rooted plants in the littoral zone area as a primary stabilizing force in Chautauqua Lake’s ecosystem. However, the research data from Racine-Johnson’s long-term monitoring of the aquatic plant community in Chautauqua Lake (2002-2019) indicates that the present littoral zone with growing rooted plants has shrunk, compared to the littoral zone area depicted on current and historical maps.

Standard Research Methods Developed and Used by Robert Johnson Since 1988

Briefly this describes the standard rake- toss, bottom-drag method used to gather and evaluate aquatic plant growth in Chautauqua Lake. (My yearly-published research reports detail the specific procedures). In predetermined locations, our biologists collect two samples of aquatic plants at the same location by our rake-toss bottom-drag method by extending two double-sided rakes attached to ropes out from the boat 15m (~50’) to retrieve any plant mass, by pulling very slowly along the lake bottom 10m (~33’) at each of the sampling points. A biologist places the plant mass into a large tray, and makes an estimate of mass retrieved based on previous Chautauqua Lake research. Then a biologist separates the mass into piles of individual species, and assigns and records a percentage of the whole mass to each species. A vital part of Racine- Johnson’s research is the ability to collect exact data on the existing aquatic plants and invertebrates, at specific times and sampling points on the lake. The staff of aquatic biologists is highly trained. There is generally 60 plus years of collective aquatic plant experience of personnel who evaluate macrophytes on our survey boat.

In 2020, the same employees will use these sampling techniques. Racine-Johnson Aquatic Ecologists’ hands-on plant sampling methodology is crucial to the accuracy of the research findings of the actual plant community: the species and amounts found in each location. It is extremely important to note that collecting less than two rake-toss bottom- drags at any location, or deviating from this collection method, will not give accurate results.

The Loss Of The Aquatic Plant Community In Chautauqua Lake’s South Basin in 2019

May 13-14. Princeton Hydro, a consultant for the Chautauqua Lake & Watershed Management Alliance collected, measured, and recorded relative density and biomass of aquatic plants (macrophytes) growing in Chautauqua Lake.

May 15-17. SOLitude Lake Management applied aquatic herbicides 2,4-D and endothall to lake areas south of Long Point on Chautauqua Lake, to control the growth of macrophytes.

May 21. Princeton Hydro collected lake water samples from the chemically treated and non-treated areas of the lake, seven days after the application of herbicides. They sent these samples to a testing lab to determine herbicide residue concentrations. Lab results showed chemical concentrations of both 2,4-D and endothall in lake areas not permitted for herbicide treatment. The results also showed that both chemicals drifted at least 1 mile from the herbicide treatment.

May 22, 23 & 29. Racine-Johnson Aquatic Ecologists conducted a Spring Aquatic Plant and Insect Herbivore Survey in the southeast end of the south basin of Chautauqua Lake. The data collection showed several plant species growing. However, the plant Potamogeton crispus had severe structural damage to leaves and stems expected after an endothall application. Additionally, there was noticeable herbicide injury to the leaves and stems of the plant species Myriophyllum spicatum, Ceratophyllum demersum and Elodea sp.

June 12. Princeton Hydro took plant biomass measurements less than one month after the herbicide treatments. They found outside of the treated area considerable decline of native plant biomass, compared to the plant biomass measurements they took on May 13-14 before the herbicide treatment.

July 1.  Racine-Johnson conducted a second Insect Herbivore Survey at four sampling stations in the southern end of the south basin. On this date, there were no species of plants present at three of the four sampling stations. In addition, there were no visible phytoplankton blooms, and the water clarity was slightly turbid from soil particles in the water column produced by wind-driven waves.

Spring/Summer. The Chautauqua Fishing Alliance (CFA), (part of a Northern U.S. Fishery Research and Education Network) described the progressive loss of vegetation in the south basin beginning in late May, through June, and into summer. The CFA also observed as the summer progressed, increasingly turbid water, and a barren lake bottom. Further, Professional Fishing Guides on the Lake, who are writers for the Musky Hunter magazine described in their Dec. 2019/Jan. 2020 articles, the same conditions of lost vegetation in the south basin.

September 19-October 1. Racine-Johnson Aquatic Ecologists conducted a Late Summer/Early Fall Plant Survey in the north and south basins of Chautauqua Lake. (a) In the north basin north of Long Point, the aquatic plant community survey showed normal plant growth, good-to-excellent water clarity, along with a robust growth of desirable macrophytes. (b) In the south basin, Racine-Johnson observed an increase in phytoplankton blooms. (c) In the southeast section of the south basin, the survey measurements showed a nearly bare lake bottom, and only a few plant fragments lying over several hundred acres.

Summary

Based on Racine-Johnson’s long-term aquatic plant database for Chautauqua Lake (2002-2019), the data suggests that the official aquatic plant management decisions taken to apply the herbicides 2,4-D and endothall on May 15-17, targeting Myriophyllum spicatum and Potamogeton crispus the naturalized, now colonized plant species, may have high environmental costs.

These environmental costs of a diminished plant community include the loss of: 1) other plant species, 2) habitats that macrophytes create in a shallow freshwater lake, 3) populations of many species within the lake’s food web, as well as other losses.

The littoral zone is a critical part of the very complicated nutrient cycling in Chautauqua Lake and can directly affect the Lake’s ongoing struggle with cyanobacteria, the harmful algae blooms (HABs). Removing aquatic macrophytes from large littoral areas is not prudent planning for Chautauqua Lake’s future.

To repeat, the littoral zone is a stabilizing force in the Chautauqua Lake ecosystem. For a healthy lake, it is essential to have a robust rooted aquatic plant community. 

(Racine-Johnson Aquatic Ecologists’ research reports include scientific references that support these statements).

Lessons from the Lake: Making Sense of the Science

by Becky Nystrom

This article was first published at chautauquawatershed.org.

Photo by Jane Conroe.

If only Chautauqua Lake, an ecological and economic treasure in our midst, could speak. How might we better understand and steward its complex ecosystems upon which so much aquatic life depends, while thoughtfully addressing the ongoing challenges of excessive plant growth, harmful algal blooms, and newly introduced invasive species? The lessons from the lake are knowingly complex and deserve our attention.

We know our lake is an old lake, rich in plant diversity and an abundance of living things. We know its “underwater gardens” are the spawning and nursery beds for bass, muskellunge, bluegill, and sunfish, and the basis for our famous warm water fishery. Nymphs of mayflies, damselflies, and dragonflies crawl among the leaf blades, feasting on tinier insects, while larvae of moths, caddisfly, and weevils forage upon tender buds and feathery foliage. Little things are eaten by bigger things, and all are woven together in an amazing web of interdependency, complexity, and connection. Beyond their importance to the food web, rooted plants release oxygen, stabilize the sediments, and reduce resuspension of silt and nutrients, all significantly improving water quality.

We know the photic zone, where light penetrates the water column, is home not only to obvious lake plants, but also to innumerable tiny green dancers, floaters, and clingers known as phytoplankton, or “algae.” Interestingly, “blue-green algae” aren’t really algae at all, but rather a form of aquatic bacteria known as “cyanobacteria.” In plant-dominated lakes such as Chautauqua, most algae and cyanobacteria are normal residents serving as microscopic oxygenators and food-producers of open waters. 

And yet…increased nutrient loading from urbanization of the watershed, erosion, loss of natural shorelines and buffered streambanks, poor lawn-care practices, and warming waters have led to weed-clogged waterways, unhappy humans, and conflicting ideas on solutions. Overgrowths of algae form unsightly and smelly surface scums. More insidiously, harmful algal blooms occur with greater frequency, some producing liver and nervous system toxins dangerous to humans, pets and aquatic creatures alike.

For decades, the Chautauqua Watershed Conservancy has strived to conserve and heal our watersheds to enhance the quality of our local waters over the long term. Our work encourages landowners, municipalities, and others to employ lake-friendly landscaping practices, construct erosion control systems, and install vegetated stream buffers, swales, and rain gardens to intercept pollutants before they flow downstream. We have protected over 1,000 acres of wooded wetlands, streambanks, shorelands, and other natural areas which absorb and filter rainfall and stormwater, reducing downstream nutrient loading and sedimentation which otherwise fuel excessive weed and algae growth in our waterways. 

Recent attempts to eradicate the long-naturalized Eurasian watermilfoil and curly-leaf pondweeds via herbicides in Chautauqua Lake have brought clashing viewpoints and confusing messaging. Alarming evidence of harm to our lake’s south basin ecology has caused deep concern and dismay over the apparent collateral damage from the narrowly-informed “quick-fix” chemical approach. Can’t we do better? What lessons may be learned?

Comprehensive scientific research by Robert L. Johnson of Racine-Johnson Aquatic Biologists (2019 Status of Chautauqua Lake’s Aquatic Macrophyte Community Determined by a Lake Summer/Early Fall Survey and Estimates of the Associated Invertebrate Community) warns that the ecological balance of the lake’s lower south basin may now be at risk. We should listen to the science. We hope that the Region 9 State Department of Environmental Conservation (DEC) will listen. 

Mr. Johnson is a highly respected scientist who has studied the aquatic plants of Chautauqua Lake, and the tiny insects that consume them, for eighteen consecutive years. His Racine-Johnson Point Intercept-Rake Drag plant sampling method is recognized as the industry standard. His methodology has been endorsed by the NYS DEC and has provided the invaluable long-term data that has guided plant management decisions by the Chautauqua Lake Association (CLA) since 2002. The entirety of his reports and all conclusions are solely the work of Racine-Johnson. He is an award-winning member, former director and past president of the Northeast Aquatic Plant Management Society and is widely recognized for his professional contributions towards improved understanding of the ecology of non-native species Eurasian watermilfoil (Myriophyllum spicatum) and Hydrilla.  He has served for many years as an independent third-party scientific herbicide-monitoring consultant for the DEC and other lake associations throughout New York.

 Compared to his May 2019 survey and previous years of sampling in the southeast end of Chautauqua Lake, Johnson’s 2019 mid-September survey revealed only barren sediment and unprecedented absence of nearly all aquatic plants. His report warned that these areas were in critical decline likely linked to the 2,4-D and endothall herbicides applied to the 388 south basin acres in May. Reports by seasoned fishermen using marine sonar concurred that nearly all traditional south basin weed lines were lost and replaced with thick algal blooms persisting into late fall. 

An earlier and very limited, third-party monitoring report by Princeton-Hydro, contracted by the Chautauqua Lake and Watershed Management Alliance, failed to identify the more widespread, longer-term outcomes documented by Johnson. Its researchers, however, did note that “total biomass…decreased markedly at the treatment sites,” and documented evidence of “potential herbicide drift and resultant reduction in non-target plant biomass” approximately 7-14 days after treatment. Because both herbicides used are known to damage plants many weeks or months after being introduced into the water column, Princeton-Hydro’s one-month study could not possibly capture those longer-term consequences revealed by the Racine-Johnson work. 

And while the Princeton-Hydro report did not address algae, the Fall 2019 Racine-Johnson report expressed concern that cyanobacteria and HABs were visually extensive and worsened as one proceeded south, consistent with herbicide application areas. It warned that the wholesale loss of rooted aquatic plants from the littoral zone could push the shallow south basin of Chautauqua Lake from a stable macrophyte-dominated state toward a turbid and undesirable algal-dominated one, with loss of our critical warm water fishery and increased risk of algal scums, cyanobacteria, and toxic HABs.

So much is at stake. There are enough lessons here to justify significant changes in future management decisions for Chautauqua Lake. Let’s listen to the science.


Rebecca Nystrom is a local naturalist and retired JCC Professor of Biology who holds Bachelor’s and Master’s degrees in biology from the University of Buffalo and SUNY Fredonia, respectively. She is a founding director of the Chautauqua Watershed Conservancy, member of the Chautauqua Lake and Watershed Management Alliance Scientific Review and Advisory Committee, and member of the Macrophyte Management Strategy Technical Review Committee.