Transcript Attack of the Aquatic Habitat Snatchers

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 mid1970s.




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