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Aquatic Vegetation

ID & Management

Todd D. Sink, Ph.D.

Assistant Professor & Fisheries Extension

Specialist

Department of Wildlife & Fisheries Sciences

Improving Lives. Improving Texas.

•AquaPlant Website http://aquaplant.tamu.edu/

•AgriLife Extension Aquaculture, Fisheries, and Pond Management Website http://fisheries.tamu.edu/

•Mobile Apps

•AquaPlant https://itunes.apple.com/us/app/aquaplant/id722310302?ls=1&mt=8

•AquaCide https://itunes.apple.com/us/app/aquacide/id722031732?ls=1&mt=8

Management Resources

Filamentous Algae

Duckweed

Hydrilla

American Pondweed

Water Hyacinth

Coontail

Duckweed

Filamentous Algae

Reasons for Aquatic Vegetation Management

• Reduce water loss – evapotranspiration

• Cattails increase water loss by 75-80%

• Reduce breeding habitat for noxious insects – mosquitoes, midges, etc.

• West Nile virus, equine encephalitis, etc.

• Improve fish & wildlife habitat

• Increase size & condition of fish

• Enhances recreational activities

Why are aquatic plants so invasive?

• Propagate by:

– Seeds

– Fragments

–Roots

–Vegetative offshoots

• Tolerate flooding & drought

Alligator weed Vegetative off-shoots

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Banana lily Seed pods

Spatterdock or cow lily Roots or rhizomes

Coontail Fragmentation

Managing Aquatic Vegetation

• First critical step….

•Identification

•Algae

•Floating

•Submerged

•Emergent

Aquatic Plant Identification

• Algae - primitive, non-seed bearing plants & no roots, stems, or true leaves

• Floating - all parts of plant floats

• Submerged - mostly underwater, rooted with flaccid stems

• Emergent - stiff or rigid stems with parts standing above the surface

• Submerged v/s Emergent

Algae

• Planktonic - microscopic floating

• Filamentous - stringy or hair-like

• Macro-algae (look like plants)

• Chara

• Nitella

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#1 Filamentous Algae Chelated copper complexes, diquat, or copper sulfate Not Mozambique tilapia

Chara – skunk grass Chelated copper complexes or copper sulfate

Floating Plants

• Duckweeds

• Watermeal

• Mosquito fern (Azolla)

• Salvinia

–common & giant

• Water lettuce

• Water hyacinth

Duckweed & Watermeal Carfentrazone, fluridone, or penoxsulam – all $$$$ Tilapia and ducks (have other issues) + flumioxazin or diquat (duckweed only)

Azolla or Mosquito Fern Carfentrazone, diquat, fluridone, flumioxazin, penoxsulam, tilapia

Water Hyacinth

Increased water loss of 200 – 300%

Non-native

Diquat, imazamox, imazapyr, or penoxsulam Manual removal

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Submerged Plants • Coontail • Eelgrass • Egeria • Elodea • Fanwort • Hydrilla • Bushy Pondweed (Southern Naiad) • Parrotfeather

• American pondweed

• Bladderwort

• Curly-leaf Pondweed

• Illinois Pondweed

• Sago Pondweed

• Variable-leaf Pondweed

• Eurasian Watermilfoil

• Variable-leaf Watermilfoil

Submerged Plants can be Confusing Egeria

Hydrilla

Elodea

Hydrilla common – Egeria & Elodea not so much

Do not rake or cut!

If unsure diquat, endothall, fluridone, or penoxsulam kills them all.

Grass Carp - E

Hydrilla Elodea Egeria

If unsure diquat, endothall, fluridone, or penoxsulam kills them all.

Grass Carp - E

Coontail

Seeds & Fruiting Bodies

Diquat, endothall, fluridone, flumioxazin Grass carp – F-G

No raking or cutting!

#3 Southern naiad (bushy pondweed)

Diquat, endothall, fluridone

Grass carp - E #4 Native, good fish habitat – can become problematic

Diquat, endothall, fluridone, imazamox Grass carp - E

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Submerged Vegetation & Treatment Issues

• 8-14 tons of vegetation per surface acre (4-6 ft deep)

• Be careful with contact herbicide treatments & submerged vegetation!

• Many tons of rotting vegetation depletes dissolved oxygen & causes fish kills!

• No more than 25-30% of pond

• No issues with systemics other than glyphosate

Emergent Plants

• Arrowhead

• Buttonbush

• Cattail

• Common Reed

• Giant Reed

• Horsetail

• Lizard’s-tail

• Pickerelweed

• Rushes & Sedges

• Smartweed

• Southern watergrass

• Torpedograss

• Waterleaf

• Waterlilies

• Water Pennywort

• Water Primrose

• Water Shield

• Willow

Alligatorweed

Non-Native

Alligatorweed Flea Beatle Imazapyr or triclopyr

Water Primrose

Land Water

#2 Glyphosate, imazamox, imazapyr, or mowing

Cattail

Increase water evaporation 250% Glyphosate, imazamox, or imazapyr

White or Fragrant

Spatterdock or Cow Lily Yellow or Mexican Lily

Banana or Floating Hearts

Water Lilies

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American Lotus

Mexican water lily Water Shield

Floating Hearts Spatterdock

White water lily

Water lilies, lotus, & spatterdock

fluridone, imazamox, imazapyr, or glyphosate

Rushes are round & sedges have edges

Glyphosate

Arundo donax or Giant Reed

0

20,000

40,000

60,000

80,000

100,000

120,000

Native Arundo

Ac

re-f

t

Annual Water Use

Imazapyr, triclopyr, glyphosate, or imazamox – then burn

Willow

180-250% increased evaporation

Dam destroyer

Glyphosate, imazapyr, triclopyr, or removal

Questions?????