Todd Sink, Ph.D.Associate Professor and Aquaculture Extension Specialist

Department of Range, Wildlife, and Fisheries ManagementTexas A&M AgriLife Extension Service

Improving Lives. Improving Texas.

Managing Aquatic Vegetation for Waterfowl

(& Wading Birds)

Aquatic Vegetation Misconceptions

• No management DOES NOT = good management

• Uncontrolled aquatic vegetation growth is not good• Ponds are manmade environments

• Invasive vegetation needs control• Invasive NOT = non-native

• Herbicides are not bad, they are a tool

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, Zika, equine encephalitis, etc.

• Improve fish & wildlife habitat • Increase size & condition of fish, wildlife food

• Too much inhibits food capture fish/birds

• Enhances recreational activities

Aquatic Vegetation Management◦ AquaPlant Website - http://aquaplant.tamu.edu/

Why does aquatic vegetation become a problem in small impoundments?

• What do plants need for growth?– Water– Sunlight– Nutrients

• Ponds are nutrient sinks – accumulate nutrients from watershed & groundwater over time!

• Healthy balance: 10-15% coverage

Why are aquatic plants so proliferative?

• Propagate by:– Seeds

– Fragments

– Roots

– Vegetative offshoots

• Tolerate flooding & drought

Aquatic Plants• First critical step….

• 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

Algae• Planktonic - microscopic floating• Filamentous - stringy or hair-like• Macro-algae (look like plants)

• Chara• Nitella

Filamentous algae Hinders recreational activitiesBirds, fish, wildlife do not eat, does not produce foodChelated copper complexes or copper sulfate plus diquat

Chara – skunk grassConsumed by many species of ducksProduce many invertebratesPropagation – pick up whole plant & transfer

Floating Plants• Best for waterfowl

• Duckweeds• Watermeal• Mosquito fern (Azolla)

Duckweed & Watermeal• Reason duckweed called “duck”weed• Can become extremely problematic small, still ponds• Many “invasive” native & non-native species• Propagation – pick up & place in new water

Azolla or Mosquito Fern• Extremely high protein, rich in vitamins• Many species of waterfowl and wildlife like to eat

Submerged Plants• American pondweed• Illinois Pondweed• Variable-leaf

Pondweed• Coontail• Eelgrass• Widgeon grass• Bushy Pondweed

(Southern Naiad)

• No –bad• Eurasian Watermilfoil• Variable-leaf

Watermilfoil• Egeria• Hydrilla

Hydrilla Elodea Egeria

Do not want!!!

If unsure diquat, endothall, fluridone, or penoxsulam

Milfoils

Native, good fish habitat – open growthWildlife food- tubers, seeds, leaves, new shootsInvertebrates

American pondweed

Good fish habitat – dense growthWildlife food- tubers, seeds, leaves, new shootsHigh density invertebrates

Illinois pondweed

Good fish habitat – dense growthWildlife food- seeds, leavesHigh density invertebrates

Eelgrass (Vallisneria)

Dense growthWildlife food- seeds, leaves, shootsHIGH density invertebrates

Widgeon grass

Coontail

Seeds & Fruiting Bodies

SeedsInvertebratesVery dense growthEasy transfer

Dense growth

Wildlife food-seeds, leaves, shoots

Invertebrates

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

Rushes are round & sedges have edges – NOTSeeds & nesting

SmartweedSeeds, seeds, seedsCover & nesting

White or Fragrant

Spatterdock or Cow LilyYellow or Mexican Lily

Banana or Floating Hearts

Water Lilies

American Lotus

Mexican water lilyWater Shield

Floating Hearts Spatterdock

White water lily

Water lilies, lotus, & spatterdockWildlife food – seedsValuable wading bird hunting habitat