Tuesday, November 12
3:30 pm – 5:00 pm

Agenda subject to change.
Updated 1 November 2019

★ Denotes that the lead author is a student. 💧 Indicates citizen science-friendly session.

 

💧 C1: Lake Level

Moderator: Colleen Prather
De Beers Canada, Calgary, Alberta, Canada

3:35 Citizen Science and Satellites: Tracking Lake Water Storage on the Ground and From Space
Grant Parkins1, Tamlin Pavelsky2, Sheikh Ghafoor3, Faisal Hossain4, Sarah Yelton1, Megan Rodgers1, and Sarina Little2
1Center for Public Engagement with Science, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina; 2Department of Geological Sciences, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina; 3Department of Computer Science, Tennessee Technological University, Cookeville, Tennessee; 4Department of Civil and Environmental Engineering, University of Washington, Seattle, Washington

Of the 20–40 million lakes in the world larger than 0.01 km2, only a few thousand receive regular water level monitoring. On-the-ground, automated monitoring of a fraction of these lakes would incur considerable expense. However, an inexpensive staff gauge installed in a lake can be read by anyone, making this an attractive alternative if a system is in place to collect and report the data.

The Lake Observations by Citizen Scientists & Satellites program (LOCSS) is working with citizen scientists in the United States, France, and Bangladesh to regularly monitor lake height in natural lakes. This data is paired with surface area measurements which are derived from satellite imagery to monitor changes in the volume of water in lakes.

We are currently studying more than 50 lakes and are testing the accuracy of measurements submitted by citizen scientists. We have found that lake level measurements submitted by citizen scientists are highly accurate when compared to pressure transducers installed at the same sites. Additionally, we have found that lake height variations are correlated within local clusters of lakes but have found that correlations among distant lakes are not significant.

During this session, we also share strategies for developing a citizen science project and consider the motivations of citizen scientists who participate in LOCSS. Finally, we share plans for expanding our lake network to 150 additional lakes in the United States, Europe, and Asia within two years.

3:55 Successful Use of Science, Engineering and Community Engagement to End a 70-Year Lake Water Level Management Conflict
Jay Toews
Toews Environmental Ltd., Winnipeg, Manitoba, Canada

Community engagement and an approach using multiple lines of scientific data collection led to building trust and collaboration with and within a divided community on a lake surrounded by mixed land uses. Beginning with conflicting anecdotal reports and a paucity of data on hydrology and water quality, data collection and synthesis included: corroboration between local knowledge and geotechnical shoreline assessments to determine a threshold lake surface elevation for shoreline erosion; corroboration among light extinction measurements, bathymetric surveys and reports from recreational boaters and fishers to determine threshold depths for nuisance vegetation growth; and, assimilation of numerous conflicting anecdotal reports to gain acceptance of the counterintuitive finding that cyanobacterial blooms were not influenced by water depths. Detailed algal taxonomy and vertical water chemistry profiling demonstrated the importance of wind-driven mixing to lake water quality, leading to a recommendation to not raise water levels. A target minimum water level was based on the ratios of lake surface elevation to surface areas and water volumes under ice cover. Synthesis of all results with hydrologic and hydraulic modeling allowed development of a Water Level Management Plan and the 100% landowner signoff necessary for its implementation. Finally, analysis of various water chemistry parameters over four seasons to allow estimation of internal phosphorus loading, together with phytoplankton biomass and vegetation biovolume measurements, will guide volunteer water quality improvement efforts and citizen-science initiatives on the lake.

4:15 Using Classification and Deep Learning Algorithms to Study Zooplankton in Lake Mead, Nevada
Deena Hannoun Giffen, Todd Tietjen
Southern Nevada Water Authority, Las Vegas, Nevada

Lake Mead is a large reservoir along the Colorado River that supplies water for drinking and irrigation to nearly 30 million users. Persistent drought conditions have caused a sharp decline in the elevation of Lake Mead, and consequently, the effects of drawdown on the reservoir are being investigated. One way to measure changes to the reservoir is through the study of zooplankton. Zooplankton are important to reservoirs such as Lake Mead as they make up the base of the food chain and are an indicator of overall reservoir health. In this study, we compile nearly thirty years of zooplankton data taken at various sampling sites throughout Lake Mead. Because of the large size of this long-term data set, we use an innovative approach, including classification algorithms and deep learning algorithms. Classification algorithms use supervised machine learning to determine underlying classifiers of the data set. Deep learning algorithms also utilize machine learning and take large amounts of labeled data and use neural networks to determine predictive factors that were previously seen as being too convoluted or too computationally intensive. The result of both approaches is twofold—deeper insight into a data set that was previously unknown, as well as a trained model that can be used for predictive purposes.

4:35 Developing Water Quantity Policy for Natural Lakes With Large Water Level Fluctuations
Catherine L. Hein
Wisconsin Department of Natural Resources, Madison, Wisconsin

Lake management often focuses on water quality, but policy tools are also needed for managing water quantity. In central Wisconsin, a region defined by thick glacial sediments and extensive irrigated agriculture, groundwater withdrawals have purportedly lowered lake levels. However, Wisconsin does not have a legal framework for defining natural lake level regimes, nor what constitutes a significant departure from them. The state legislature mandated the Department of Natural Resources to study three lakes in the Central Sands and determine what defines a significant decrease in lake levels. We hindcasted lake levels using a Bayesian Hierarchical Model and found a large amplitude of fluctuation on all three lakes. We then examined the potential impacts of lowered lake levels on the cation/anion balance, stratification and internal nutrient loading, benthic primary productivity, aquatic and wetland plants, fish, and recreational boating. Each lake was unique with its own limiting criteria. Whereas the life cycle of an endangered plant dependent on fluctuating lake levels was critical in a shallow, wetland lake, lake stratification and waterskiing were more important in a deep, populated lake. This study exemplifies the importance of using the best available science to inform natural resource management and will hopefully pave the way toward water quantity policy for lakes across the state.

 

💧 C2: Using Social and Interactive Media to Advance Lake Management

Moderator: Ryan Mitchell
Lake Champlain Basin Program, Grand Isle, Vermont

3:35 The Water Resources Report: Mapping Social Media for Water Resources
Kelly Smith and Matt Hodge
Hodge.WaterResources LLC, Brighton, Massachusetts

The Water Resources Report (WRR) (at http://waterresourcesreport.com/) is a web application developed by Hodge.WaterResources to aggregate, distill, and map information from Twitter about rivers, lakes, and ponds across the United States.

Each day, the WRR reads the Twitter feeds of an ever-growing list of state organizations and NGOs that have a role in managing water resources, and it searches for instances of named water bodies. When the WRR matches a named water body to a location in the USGS Geographic Names Information System (GNIS), it maps that tweet with a symbol that indicates the recency and number of Tweets for that water body. To date, the WRR has mapped approximately 9,000 Tweets to over 2,000 locations.

A user of the WRR can navigate to an area of interest on the map and simply click on a water body to see what is being said on social media about that water body. The WRR is innovative in its approach to assigning the geographic location to a tweet because it assigns that location based on the content of the tweet as opposed to the location of the tweeter.

The WRR helps to increase community involvement and civic engagement with water resources. The WRR is a tool for scientists, engineers, advocates, and all stakeholders to learn about, discuss, and keep current with activity happening on the water bodies they care about.

3:55 Telling the Story of Indiana Lake Water Quality With Interactive Web-Based Mapping and Data Visualization
Cory Sauve
Indiana University, Bloomington, Indiana

Lake water quality monitoring programs have historically communicated results through traditional methods like written reports and presentations. While these methods may effectively communicate information to a targeted group, they often fail to reach all stakeholders interested in lake water quality. Recent advancements in web-based and open source technologies provide programs with the ability to not only reach a larger group of stakeholders, but to allow for individuals to view data in an interactive and customizable way.

The Indiana Clean Lakes Program is a multifaceted water monitoring and educational program incorporating both annual monitoring and citizen science to assess Indiana lake water quality. The Indiana Clean Lakes Program has sampled over 2000 lakes since 1989 through annual monitoring, and currently includes over 80 volunteer lake monitors. This talk will illustrate how the program has used Esri Story Maps and Shiny from R Studio to build interactive web-based maps and visualizations displaying these data to stakeholders across Indiana.

4:15 An Online Approach to Increasing Public Understanding of Lake Ecology and Management
Jo A. Latimore1, Bindu Bhakta2, Erick Elgin3, Paige Filice4, and Lois Wolfson1
1Michigan State University, East Lansing, Michigan; 2Michigan State University Extension, Pontiac, Michigan; 3Michigan State University Extension, Fremont, Michigan; 4Michigan Department of Environment, Great Lakes, and Energy, Lansing, Michigan

Lake conservation and management are often addressed at the local level. In Michigan, USA, decision making for inland lake management lies largely with local governments and stakeholders. Good decisions require local citizens to understand lake ecology, management options, and legal and social frameworks. In response, we created a new, online “Introduction to Lakes” program. This engaging 6-week course is delivered with innovative instructional technology and user-friendly for individuals with no prior experience with online learning. The course includes video lectures, individual learning activities, interactive discussion forums, quizzes, and live chat sessions with content experts. Ninety-nine people participated in the first offering (2015), far exceeding our expectations, and interest has only grown in subsequent years, with over 600 people taking the course over a total of four offerings to date. Learners include lakefront property owners, educators, lake management professionals, and local government officials. Assessment data demonstrate substantial improvement in understanding of course topics. Furthermore, 85% of participants intend to apply their learning to local lake management efforts, and 97% would recommend the course to a friend or colleague. “Introduction to Lakes” is empowering communities to protect their freshwater resources and can serve as a model for freshwater science and management communication.

4:35 The People Behind the Process: Water Authority Socioeconomic Decisions in the Implementation of the Water Framework Directive
Maggie Armstrong1, Elisabeth Ruijgrok2, Guus Kruitwagen2, and Lisette de Senerpont Domis1
1Aquatics Department, Netherlands Institute of Ecology, Wageningen, The Netherlands; 2Ecology Department, Witteveen+Bos, Deventer, The Netherlands

Eutrophication and climate change have been identified as key drivers of water quality deterioration worldwide. Mitigation of the compound effects of these stressors necessitates the implementation of preemptive, multidisciplinary management measures. Given the diversity of ecological, social and meteorological parameters around the world, there can be significant variations to the inventive approaches that water managers take while pursuing preventative and/or restorative actions towards mitigating the negative consequences of eutrophication and climate changes on ecosystem functioning and services.

The European Union’s Water Framework Directive is an international law, which enforces EU member states to have all ground and surface waters in the EU in good ecological status relative to the water body’s type and historical state. Within the context of the EU-WFD, we are assessing the approaches of water managers in implementing rehabilitation plans, and more specifically how they evaluate their rehabilitation plans in terms of socio-economic benefits. Due to the influence that the availability of ecosystem services has on stakeholders and society at large, we hypothesize that water managers are also integrating these values into their rehabilitation plans. More specifically, we are inventorying what type of socio-economic appraisal techniques water managers are using in the development of rehabilitation plans.

In order to test this hypothesis, we are collecting data from water management organizations throughout Europe using online surveys as well as in-depth qualitative interviews. We will analyze these data for trends in approaches towards improving the ecological status and the inclusion of socioeconomic values. By sharing the common practices of approaches taken towards fulfilling the WFD, the results of our study can inform water managers in Europe and beyond on the most efficient manner for developing benefit-oriented rehabilitation plans.

 

💧 C3: Salt I – Impacts in the Adirondacks

Moderator: Kris Stepenuck
University of Vermont, Burlington, Vermont

3:35 A Reduction in Spring Mixing Due to Road Salt Runoff Entering Mirror Lake (Lake Placid, New York)
Brendan Wiltse1, Elizabeth Yerger2, and Corey Laxson2
1Ausable River Association, Wilmington, New York; 2Paul Smith’s College Adirondack Watershed Institute, Paul Smiths, New York

Road salt has resulted in the salinization of surface waters across temperate North America. Increasingly, road salt is recognized as a significant regional pollutant in the Adirondack Park. Here we analyze bi-weekly limnological data from Mirror Lake (Lake Placid, New York) to understand the role of road salt runoff on an apparent lack of complete spring mixing in 2017. Water column profile data show notable spatial and temporal variability in chloride concentrations within the lake. Concentrations are highest at the lake bottom during the winter, with increases associated with the onset of road salt application to the watershed. High chloride concentrations in the hypolimnion persisted through the summer of 2017 due to a lack of complete spring mixing as the result of road salt induced density differences within the water column. Water density calculations and Schmidt stability point to an increase in water column stability due to the accumulation of salt at the lake bottom. The incomplete spring mixing resulted in greater spatial and temporal extent of anoxic conditions in the lake bottom, reducing habitat availability for lake trout. Restoration of lake mixing would occur rapidly upon significant reduction of road salt application to the watershed and improvements in stormwater management.

3:55 High-Resolution Assessment of Road Salt Export to Blue Mountain Lake
Corey Laxson, Elizabeth Yerger, Hunter Favreau, and Daniel Kelting
Paul Smith’s College Adirondack Watershed Institute, Paul Smith’s, New York

Widespread use of road salt has resulted in salinization of many lakes in the Adirondack region of New York State (NYS). Although several studies have documented the regional extent of salinization, few have quantified the total export of salt from a watershed to a receiving lake. Blue Mountain Lake is significantly impacted by road salt. Chloride concentration in the lake is 85 times higher than nearby un-impacted lakes and has tripled over the last several decades. The lake’s watershed is drained by five tributaries, three of which contain heavily salted NYS roadways, with the remaining two draining unimpacted forestland. A combination of in-stream stage and conductivity recorders, as well as discharge measurements were used to quantify chloride export to the lake at 30-minute intervals over a 3-year study period. We found that the export of chloride from unimpacted watersheds was quite low and ranged from 5 to 7 g/ha/day. Conversely, export from watersheds containing NYS roads were as up to 170 times higher, with export coefficients as high as 16,000 g/ha/day observed during periods of spring runoff. Overall, we quantified a total of 167,000 kg of chloride exported to the lake in water year 2015, and 162,000 kg in 2016. We estimate that over 98% of this chloride can be attributed to the salting of less than 5 km of NYS roads. This type of high-resolution data improves our understanding of the movement of road salt through the environment and provides a baseline for gauging the efficacy of forthcoming changes to winter road management.

4:15 Effects of Road Salting on Surface Water Chemistry of Adirondack Lakes
Daniel Kelting and Corey Laxson
Adirondack Watershed Institute, Paul Smiths, New York

Salinization of surface water from sodium chloride (road salt) applied to paved roads is a widely recognized environmental concern in the northern hemisphere. Nearly 7 million tons of road salt has been applied to the paved roads in the Adirondack Park over the last 40 years. Runoff from this network enters more than half of streams and about one-third of lakes in the Park, making road salt a potentially significant regional pollutant. We confirmed road salts’ regional significance using a dataset of 138 lakes with varying paved road densities in their watersheds. Fifty-six lakes in watersheds without paved roads had median sodium and chloride concentrations of 0.55 and 0.24 mg/L, respectively, while the remaining 82 lakes in watersheds with paved roads had median sodium and chloride concentrations of 3.60 and 7.22 mg/L, respectively. In addition to salinization, further changes in lake chemistry resulting from soil ion exchange may occur. We determined that lakes in watersheds with paved roads were less acidic and had higher concentrations of nitrate, sulfate, calcium, potassium, and magnesium compared to lakes in watersheds without paved roads. We also found that cation and anion concentrations were positively correlated with paved road density, providing strong evidence connecting road salt and lake chemistry, and support for soil ion exchange as the mechanism. Salt-driven changes in lake chemistry are similar to changes documented from acid deposition. As many watersheds experience both acid deposition and road salting, these co-occurring stressors should be accounted for in assessing lake chemistry and ecosystem health.

4:35 Model for Protection – Lake George Road Salt Reduction Initiative
Chris Navitsky
Lake George Waterkeeper, Lake George, New York

Through partnerships, innovations, and direct investments dedicated to “reducing the use,” The FUND for Lake George is leading a concerted initiative now realizing significant reductions in road salt with the target goal of achieving a 50% reduction basin-wide by 2020. The Lake George Road Salt Reduction Initiative is designed to serve as a scalable Best Practices model recognized throughout New York State and the nation.

The Lake George Road Salt Reduction Initiative’s Project Roadmap illustrates the deliberate progression of science-guided actions for continuous measuring as Best Practices are applied town-by-town, the reduction results of which are being documented by the most advanced technologies ever applied to this intensifying threat. From empowered science to sustaining solutions, steadfast commitment and leadership in pursuit of environmental excellence undergird the efforts in the Lake George region consisting of municipalities in Warren, Washington and Essex Counties to create the first watershed-wide tracking program in North America. Additionally, The FUND is working to have municipalities become SWiM™ (Sustainable Winter Management) Certified, a developed certified program that is focused best practice implementation.

 

C4: Voice of Experience

Moderator: Ken Wagner
Water Resource Services, Wilbraham, Massachusetts

3:35 A Lot Is Different … but Some Things Never Change
Ginny Garrison
Retired, Vermont Department of Environmental Conservation, Lakes and Ponds Management and Protection Program Manager, Waterbury, Vermont

Unlike many people in the lake management field, I don’t have childhood memories of spending time on and around a lake. However, my family did have a camp beside a stream in the Catskills and I spent many hours playing in the water, catching pollywogs to take home and watch grow into frogs, and swimming in the refreshing pools. But rather than those experiences, it was probably the shocking (horrifying) discovery during my college days of raw sewage flowing down a beautiful hemlock-lined stream into the Androscoggin River in Maine that resulted in my ultimate career path.

My lake management career with the (then) Vermont Department of Water Resources began in early 1974, just as the nascent environmental movement was sweeping the country. The USEPA was only a few years old, the Clean Water Act had recently been passed, and NALMS wasn’t even a sparkle in its founders’ eyes. Lots of discoveries and changes in the field of limnology came about during the 35 years I worked for the State of Vermont. In this presentation I’ll speak from the perspective of a state lakes program manager about the way things were, how things have changed, and the lessons I learned over the years that are still relevant today.

3:55 Lessons Learned From Thirty Years of Running a Volunteer Monitoring Program
Linda Green
URI Watershed Watch Program, URI Cooperative Extension, Kingston, Rhode Island

Linda Green, inaugural and thirty-year director of URI Watershed Watch (WW) shares anecdotes and lessons learned from over three decades running a large statewide (and then some) volunteer water quality monitoring program for not only lakes and ponds but rivers, streams and salty sites. What was the genesis of WW? How did we figure out the what, where, when, how and who? Who to partner with and how to meet diverse goals? How to fund a long-term cost-effective program that many think should be free (after all aren’t they volunteers)? How to figure out and meet data quality objectives? How to not only survive, but thrive in challenging times?

4:15 A Retrospective Look at Some Oft-Inconvenient “Words of Wisdom”
Robert Kirschner
Retired Director of Restoration Ecology and Curator of Aquatics, Chicago Botanic Garden, Rhinelander, Wisconsin

Like my two colleagues on this panel, I had the incredible fortune of my career beginning just as lake management in the United States hit “prime time.” It was the mid-1970s: Earth Day and the US EPA were only a few years old, and inspired in part by the infamously burning Cuyahoga River, the Clean Water Act amendments were passed when, with exceptional bipartisan support, Congress overwhelmingly overrode President Nixon’s veto. Funds for research, demonstration, and outreach soon flooded into state and federal programs for the restoration and protection of water resources. NALMS was born! It was an exciting time for a young and rebellious limnologist; I literally couldn’t wait to get up and go to work every day (well, almost). In the ensuing years, the federal Clean Lakes Program sparked ambitious initiatives at all levels of government and within the nonprofit sector. Myriad efforts were successful, but many have not sustained to the current day. Why? In a society bombarded with environmental challenges, how can we elevate our mission for quality lakes? Using a potentially annoying litany of “words of wisdom” that our parents and elders used to pester us with, we’ll explore how more than a few of these are actually grounded in sound science—and how, perhaps, we can use these little gems to help guide our path forward.

4:35 Extended Discussion

 

C5: Harmful Algal Blooms II

Moderator: Victoria Chraibi
Tarleton State University, Stephenville, Texas

3:35 Evolution of a Harmful Algal Bloom Program, a Perspective From Kansas
Megan Maksimowicz, Patricia Haines-Lieber, Elizabeth Smith, and Trevor Flynn
Kansas Department of Health and Environment, Topeka, Kansas

Since 2010, Kansas Department of Health and Environment has operated a response-based monitoring program for Harmful Algal Blooms. As a state agency that serves both human health and environmental concerns under one roof, we are challenged by all the complexities that HABs represent: health concerns, economic disruption, evolving science, unpredictability of blooms, prevention and mitigation, public misconceptions, and watershed management.

Kansas has gone from nine lakes on advisory in 2010 to 33 lakes on advisory in 2018. The first advisory limits were founded on World Health Organization’s guidelines for cell count and microcystin thresholds in recreational waters. Over time, these have been adjusted based on regional science as well as national and international guidelines. Each year, we synthesize data, incorporate new research findings and regulatory guidelines, and incorporate stakeholder concerns to update our approach. The product of this work is a dynamic document, the “Harmful Algal Bloom Response Plan.”

Blooms have increased in frequency and duration, so we must continually balance our available resources to meet the challenges. We maintain close coordination with human and animal health colleagues in other agencies and state emergency management. In 2019 we established a voluntary pilot program for Public Water Supplies to monitor cyanotoxins in raw and finished water, which has so far enlisted twenty producers from across the state. In 2019, we have placed extra emphasis on public education and outreach. Here is one agency’s perspective on how a Harmful Algal Bloom program was built and what the future might bring.

3:55 Cyanobacterial Harmful Algal Bloom Outreach in Wisconsin: A Partnership Between the Wisconsin Department of Natural Resources and the Wisconsin Division of Public Health
Gina LaLiberte1 and Amanda Koch2
1Wisconsin Department of Natural Resources, Madison, Wisconsin; 2Wisconsin Division of Public Health, Madison, Wisconsin

Cyanobacterial harmful algal blooms (CHABs) are of increasing interest and concern to the public in Wisconsin. The majority of Wisconsin’s 14,000 lakes do not experience significant CHAB issues, but recurring problems in some eutrophic systems have led to growing awareness of CHAB impacts on lake users and homeowners. The Wisconsin Department of Natural Resources (WDNR) and the Wisconsin Division of Public Health (WDPH) are called on to provide information about statewide CHAB occurrence, health impacts, and management strategies to the public. WDNR and WDPH staff work closely with each other on CHAB information and outreach, ensuring messaging consistency between the two agencies. This cooperative approach grew out of the agencies’ partnership which anchors the Wisconsin Harmful Algal Bloom Surveillance Program. The Wisconsin HAB Surveillance Program began in 2008 with a grant to the WDPH from the Centers for Disease Control and focuses on investigating CHAB-related illness complaints. Cooperative outreach efforts of the two agencies includes yearly presentations on CHAB identification, health impacts, and risk management at the Wisconsin Lakes Partnership Convention, annual CHAB webinars hosted by WDNR, presentations to local public health departments, lake associations, and summer camp groups, and collaborative work to develop outreach materials with information consistent across the two agencies.

4:15 Potential Techniques for Improving Analysis of and Response to Harmful Algal Blooms
Gerald A. Burnette
Civil and Environmental Consultants, Inc., Franklin, Tennessee

Harmful Algal Blooms (HABs) are increasing in both frequency and intensity. Because of this, organizations that manage reservoirs face new pressures to address identification and notification of HAB occurrences in a timely manner. The desire to improve responses to these events is driving some organizations to revisit their procedures related to algal testing. Proper analysis of and response to HABs may require approaches that are different from those used for traditional phytoplankton analysis. The time-critical nature of HAB response means faster and more efficient analytical techniques become essential to meeting expectations. The US Army Corps of Engineers manages many reservoirs, and in this context is evaluating best practices related to HAB management. A primary objective is to identify techniques that show the most promise for improving identification and response times, and incorporate these into existing programs and projects that involve potential HABs. An additional objective is to incorporate these practices into existing software used for managing water quality data. This presentation will summarize the direction and initial results of various techniques that have been evaluated to this point.

4:35 Optimizing Harmful Algal Bloom Monitoring
Anne Wilkinson and Joe Bischoff
Wenck Associates, Minneapolis, Minnesota

Harmful Algal blooms (HABs) are a ubiquitous ecological and public health risk as they have the potential to produce cyanotoxins, i.e., microcystin. Prediction and management are imperative to mitigate these risks; however, cyanobacteria blooms are highly spatially and temporally variable making monitoring, managing and prediction difficult. To further complicate the issue for lake managers, toxin production does not necessarily coincide with biovolume accumulation. This phenomenon has been observed in several Minnesota Lakes throughout the open water season. The unpredictable relationship between HABs and toxin production is problematic for managers as they are developing monitoring plans. Additionally, there is a wide range of equipment, test methods and sampling frequencies that must be worked out. Thus, sampling plans can be expensive and inefficient. This presentation will outline three tiers of sampling plans at costs ranging from $100–$10,000. Each of the three plans provide a different level of HAB analysis and can be applied to lakes with different HAB history, trophic status and recreational or water supply risks. The goal of this presentation is to provide managers with different sampling plan options that can be tailored to different budgets and HAB risks to protect public health.

 

C6: Potpourri

Moderator: A.J. Reyes
Northeast Aquatic Research, Putnam Valley, New York

3:35 Integrating Health and Safety Into Our Management Projects
Christopher Mayne
GZA GeoEnvironmental, Inc., Glastonbury, Connecticut

Managing lakes and reservoirs for a living is rewarding work. However, there are many inherent occupational dangers that can cause serious injury or even death. These hazards include struck-by, caught-in-between, chemical exposures, drowning, biological hazards including cyanobacteria, slip, trip and fall hazards, electrical hazards, environmental hazards, powered vehicle hazards, and ergonomic issues. This presentation provides a discussion of safety issues involved with working on or near surface waters. There are a surprising number of unique projects that occur on or near lakes / reservoirs creating specialized hazards that must be addressed before work can commence. Discussions will include methods of hazard identification and risk assessment, control strategies, training, as well as case studies. The design of safety control measures into our work plans should be integral and a core element of our project planning process.

3:55 Low Dissolved Oxygen in Stratified Stormwater Ponds Causes Release of Phosphorus
Vinicius Taguchi1, Ben Janke2, Jacques Finlay2, and John Gulliver1
1St. Anthony Falls Laboratory, Department of Civil, Environmental, and Geo- Engineering, University of Minnesota, Minneapolis, Minnesota; 2St. Anthony Falls Laboratory, Department of Ecology, Evolution, and Behavior, University of Minnesota, St. Paul, Minnesota

The original design recommendations from the US EPA National Urban Runoff Program (NURP) recommended that stormwater ponds have a permanent water depth ranging from 1 to 8 meters. This would allow for particulate settling while avoiding stratification and anoxia that could lead to phosphorus release from captured sediments. Subsequent studies have since observed stratification in shallow stormwater ponds, some even as shallow as 40 cm. Other studies have observed that this stratification can last as long as 10 to 30 days, even in shallow ponds. In a study of 6 intensively-monitored shallow stormwater ponds (< 3 m deep) in the Minneapolis-St. Paul metropolitan area, supported by seasonal surveys of 25 additional shallow ponds in the surrounding area, we observed widespread and persistent stratification in many ponds. In some, density stratification from winter road salt applications set up chemostratification long before thermostratification established in the summer. It is also possible that the early presence of chemostratification facilitated the formation of thermostratification and could even have strengthened it. In other ponds, especially those with little tree sheltering, wind mixing may have prevented long-term stratification. Still other ponds, where tree sheltering was abundant, were observed to be stratified even without the presence of excessive road salts. Stratification appears more widespread than expected in shallow stormwater ponds. As a consequence, ponds may experience lower oxygen than they were designed for. This can result in anoxic (< 1 mg/L dissolved oxygen) sediment phosphorus release and long-lasting stratification may increase annual release and of phosphorus from storm ponds, greatly reducing their effectiveness as a water quality treatment practice.

4:15 Case Study of Modeling a Mine Pit Lake: Continental Pit, New Mexico
Stephen Klein
Benthica, Elizabeth, Colorado

A mass balance model was developed to predict the long-term evolution of chemistry in the Continental Pit at the Cobre mine near Silver City, New Mexico. The model includes hydrologic processes, solute mass loadings from rock weathering, thermodynamic equilibrium, thermal and chemical stratification, and primary productivity. Hydraulically, the pit lake is simulated as a terminal lake with inflows from groundwater and direct precipitation into the pit, with evaporation from the lake surface, and no outflows. Solute production rates by weathering are calculated from laboratory tests on rocks collected from the pit, and a model of oxygen diffusion into and reaction with the pit walls. The unequilibrated solute concentrations from the mass loadings were periodically corrected to an equilibrium composition using MINTEQ. Stratification and mixing were predicted using GLM. Due to the morphometry, a one-dimensional model of primary productivity was used.

The lake is predicted to fill to an elevation of 2009 meters after 300 years with a maximum water depth of 95 meters. Predicted sulfate concentrations are driven by groundwater input and increase essentially linearly with time due to evapoconcentration. Initially, the lake stratifies on a seasonal basis, however the lake becomes meromictic with chemical stratification, and an anoxic monimolimnion. Uncertainties in P release from weathering result in different predicted levels of primary productivity, however, the deep water and sediment become a sink for P.

4:35 Trout Stocking Effects on Algae Blooms in Washington Lakes
Rob Zisette
Herrera Environmental Consultants, Seattle, Washington

The trophic cascade effects of trout stocking on cyanobacteria blooms in Washington lakes is being evaluated using two existing data sets. The first data set includes 50 years of comprehensive water quality, phytoplankton, zooplankton, and trout stocking data for Liberty Lake located in eastern Washington. The second data set is from 90 other Washington lakes with at least 10 years of data from routine monitoring of water quality (field parameters, nutrients, and chlorophyll), cyanotoxins during blooms, and trout stocking. These data will be supplemented with lake morphometry and climate data to evaluate relationships among the key metrics on a seasonal, annual, and spatial basis using principal component analysis. This analysis will be followed by either multiple regression or decision tree analysis depending on the observed relationships. Analysis findings will be discussed with lake and fisheries managers to develop recommendations for potential modification of trout stocking practices Washington State. This presentation will include data analysis findings for feedback prior to stakeholder involvement and project reporting.