Aquatic Plant Management

Aquatic plants are an important element of any aquatic ecosystem, providing oxygen via photosynthesis. They also provide critical habitat and food resources to a wide variety of fish and wildlife species. Quite often, aquatic plants become overly abundant, negatively impacting not only the ecological balance of the pond or lake, but also the recreational uses that the pond / lake might be providing. The keys to successful aquatic plant management are:

• Developing realistic pond / lake management goals that reflect the owner’s recreational uses and fish management priorities, and also includes an aquatic plant management strategy consistent with those goals.
• Limit unwanted, non-pond inputs of nutrients to the pond or lake that are the primary cause of excessive plant growth, particularly algae and duckweeds.
• Avoid excessive amounts of shallow water less than 8 feet deep.  A good rule-of-thumb is to have 75% of the pond or lake 8 feet or deeper.
• Maintain bottom slopes of 3:1, meaning for each additional three feet from shore, the water is one foot deeper.
• Actively control aquatic invasive (non-native) plants as they exhibit explosive growth patterns and often create plant monocultures.

On succeeding web pages, you can find information about:

• Major categories of aquatic plants
• Causes of excessive aquatic plant growth
• Benefits and disadvantages of aquatic plants
• Non-chemical control options (grass carp, dyes, aeration)
• Chemical options
  • Legal considerations
  • Importance of product labels
  • Available aquatic herbicide / algaecide products and associated water use restrictions
  • Which Aquatic Herbicide to Select
  • Planning to use chemicals effectively and safely
  • When to apply chemicals, avoiding fish kills

What Ohio’s Pond & Lake Owners Have Told Us About Their Aquatic Plants

Do you feel you have an aquatic plant problem?

Yes – 68.9 %
No – 31.1% %

What groups of aquatic plants are causing you problems?
When asked to check all groups of aquatic plants that are causing them problems, Ohio’s pond & lake owners identified the following groups (note: percentages do not add to zero as owners could check multiple groups of plants):

Planktonic algae – 5.5 %
Filamentous algae – 79.6  %
Submerged, rooted plants – 47.5 %
Floating leaved plants – 17.3 %
Emergent plants – 29.6 %

What control measures have you used?
When asked to check all control measures they’ve used, Ohio’s pond & lake owners identified the following measures (note: percentages do not add to zero as owners could check multiple measures):

No attempt to control – 14.2 %
Mechanical removal – 39.5 %
Biological control – 46.9 %
Chemical control – 65.4 %

Did You Know?

Pond owners are typically most successful in managing / controlling aquatic plants by using a variety of strategies. Nearly 55.4 % of Ohio’s pond & lake owners said they use two or more control measures annually.