Attack of the Aquatic Habitat Snatchers

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Attack of the Aquatic Habitat Snatchers

• By Cynthia Ribitzki
• For SWES 474

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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

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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

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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

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Typha Angustifolia

• Displaces native plants
• Impedes water flow
• Increases sedimentation
• Changes sediment chemistry
• Green Areas indicate Typha regions

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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
• Ill enlighten you on the problems this can cause.

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Myriophyllum Spicatum (Eurasian water-milfoil)

• Explosive growth during early colonization
• Forms dense mats
• Reduces food quality
• Reduces oxygen levels in water

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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

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Spartina Alterniflora (Smooth Cord Grass)

• Ecosystem Engineers
• The San Francisco INVASION
• The European INVASION

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S. Alterniflora (cont.)

• Ecosystem Engineering
• The indirect or direct control of resource
  availability mediated by an organisms ability to
  cause physical state changes in abiotic or biotic
  materials in essence the creation, destruction,
  or modification of habitats. -(Crooks 2002)

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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

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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

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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.
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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.

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Conclusion?

• Aquatic Habitat Snatchers are running a muck!
• AGH!

Just Kidding!
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Solutions

• Suggested Control Methods for S. alterniflora and
  its hybrids
• Selectively removing them from native marshes
  where invasion has not run a muck
• Herbicide sprays
• Monitor un-invaded marshes to prevent future
  invasions
• Use only S. foliosa for restoration projects