Docstoc

Aquatic

Document Sample
Aquatic Powered By Docstoc
					Attack of the Aquatic Habitat
          Snatchers
         By: Cynthia Ribitzki
           For: 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
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 muck
      Herbicide sprays
      Monitor un-invaded marshes to prevent future
      invasions
     Use only S. foliosa for restoration projects

				
DOCUMENT INFO
Shared By:
Categories:
Tags:
Stats:
views:15
posted:9/5/2012
language:English
pages:16