Attack of the Aquatic Habitat

Snatchers

By: Cynthia RibitzkiFor: SWES 474

Aquatic Habitat Snatchers

Alter the surrounding ecosystem by Changing surround benthic and

pelagic animal communities Displacing native plants Shifting chemical processes (i.e. like the

nutrient cycle) Changing sediment characteristics and

deposition

Tamarix (Salt Cedar)

Eliminates surface water, lowering the local water table

Increases salinity of soil Tolerates up to

36,000ppm Increases

frequency, intensity, and effect of fires and floods

Melaleuca Quinquenervia (Melaleuca)

Turning “River of Grass” into “River of Trees”

In 50 years, it has taken over hundreds of thousands of acres of Everglades

Typha Angustifolia

Displaces native plants

Impedes water flow Increases

sedimentation Changes sediment

chemistry

Green Areas indicate Typha regions

Eichhornia Crassipes (Water Hyacinth)

an acre of water hyacinth can weigh more than 200 tons; infestations can be many, many acres in size; mats may double their size in as little as 6-18 days

I’ll enlighten you on the problems this can cause.

Myriophyllum Spicatum (Eurasian water-milfoil)

Explosive growth during early colonization

Forms dense mats Reduces food

quality Reduces oxygen

levels in water

Hydrilla verticillata (Hydrilla)

One square meter of hydrilla can produce 5,000 tubers.

Tubers can withstand ice cover, drying, herbicides, and ingestion and regurgitation by waterfowl.

Once hydrilla becomes established, it is readily spread by waterfowl and boating activities.

Growth creates dense mats Promotes anoxia Limits movement of predatory species

Spartina Alterniflora (Smooth Cord Grass)

Ecosystem Engineers

The San Francisco INVASION The European INVASION

S. Alterniflora (cont.)

Ecosystem Engineering “The indirect or direct control of

resource availability mediated by an organism’s ability to cause physical state changes in abiotic or biotic materials… in essence the creation, destruction, or modification of habitats.” -(Crooks 2002)

S. Alterniflora vs. S. Foliosa

S. foliosa is the native species of cordgrass in the San Francisco Bay area.

S. alterniflora was introduced in the mid-1970s. 60 cm taller Produces almost 10-fold the above

ground biomass Higher potential for sexual reproduction Spreads laterally 1.5 times faster

The S. Alterniflora Invasion Continues

Impedes water flow Causes threat of channel blockage in

narrow up-river channels Covers open mud Changes patterns of species diversity

The European Invasion: S. anglica is born!

S. Alterniflora is the maternal genome donor of S. anglica.

This could explain why S. anglica is covering most of the coast along the British Isles.

The Threat of Invasion

S. alterniflora has the ability to “homogenize biotas across biogeographic realms and alter evolutionary pathways”.

A few offspring of S. alterniflora can threaten the abundance of plant species in Europe and the extinction of S. foliosa in the San Francisco bay area, if the hybrids have superior male fitness.

Conclusion?

Aquatic Habitat Snatchers are running a muck!

AGH!

Just Kidding!

Solutions

Suggested Control Methods for S. alterniflora and its hybrids

Selectively removing them from native

marshes where invasion has not run a muckHerbicide sprays

Monitor un-invaded marshes to prevent future

invasions Use only S. foliosa for restoration projects