A newly updated educational guide will help ensure that aquatic pesticide application in Ohio is sustainable and supports water quality, in part thanks to contributions from Ohio Sea Grant.
Mark Warman, Ohio Sea Grant Extension Specialist, played a key role in recent updates to Ohio State University Extension’s Aquatic Pest Control Study Guide alongside other partner agencies, serving as a technical adviser.
Curly-leaf pondweed, pictured here obstructing a paddler, is a major aquatic invasive species in Ohio.
The study guide, which had not been updated since 2007, helps people successfully prepare for and pass the Aquatic Pest Control (Category 3A) commercial applicator license exam from the Ohio Department of Agriculture. With the recent updates, the guide provides clear, current, and practical information to support safe and effective management of invasive and nuisance aquatic vegetation.
“It’s important to provide recent information to anyone using pesticide in aquatic environments because those systems are often connected to shared, public water resources,” Warman said. “Keeping this guide up-to-date helps applicators make informed decisions for effective treatments while safeguarding water quality, fish and wildlife, and the overall health of aquatic ecosystems.”
Updates were needed for a number of reasons, Warman explained: new pesticides have been developed over the years, plants and algae sometimes develop resistance to common pesticides, and resource managers have adopted more sophisticated application techniques and equipment. Pesticides can also potentially be overapplied, affecting water quality, or move off target, harming unintended organisms.
Through the project, Warman worked with organizers Dr. Mary Ann Rose and Chrissy Kaminski of OSU Extension’s Pesticide Safety Education Program to conduct a comprehensive review of the manual, enhancing clarity and accuracy while prioritizing key topics. Ohio Sea Grant also contributed new photos of aquatic invasive plant species to strengthen the guide’s usability.
Other partner organizations the program collaborated with included the Ohio Department of Agriculture, the Ohio Environmental Protection Agency, Columbus and Franklin County Metro Parks, Cleveland Metroparks, and aquatic management company AquaDoc.
“I’m proud of new definitions and real-world examples the study guide provides,” Warman said. “I think it makes the most recent science accessible and relevant to readers.”
For example, the guide includes information on prevention resources such as “Clean, Drain, Dry” to help boat owners cut down on the spread of nuisance plants and algae.
Since the guide was released in December 2025, it has seen strong adoption, selling more than 150 print or PDF copies. During that same period, 230 new people have taken the applicator license exam.
“We were very happy to partner with Sea Grant on this, and I’m very proud of the publication that we produced,” said Kaminski, Extension Program Manager. “Mark was critical in providing information on plant biology, photos, and critiques of drafts. His contributions helped make the manual both accurate and relevant to aquatic pest managers.”
Ohio Sea Grant is supported by The Ohio State University College of Food, Agricultural, and Environmental Sciences (CFAES) School of Environment and Natural Resources, Ohio State University Extension, and NOAA Sea Grant, a network of 34 Sea Grant programs nation-wide dedicated to the protection and sustainable use of marine and Great Lakes resources. Stone Laboratory is Ohio State’s island campus on Lake Erie and is the research, education, and outreach facility of Ohio Sea Grant and part of CFAES School of Environment and Natural Resources.