Download Troubled Waters

Troubled Waters:
Biological Invasion of Our Aquatic Resources
Aquatic Invasive Species Workshop
June 22, 2011
San Rafael, California
Ronald Smith
United States Fish and Wildlife Service
Aquatic Invasive Species Program
Pacific Southwest Region
Outline of the Presentation
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Problem
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Pathways
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Examples of some invasive flora and fauna
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New invaders of concern
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What you can do
Problem with Non-native Invasive Species
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Economic cost to U.S.
 Damage to infrastructure
 Loss of resources
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2nd leading cause of native species’
extinction/endangerment
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Loss of global biodiversity
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Human health risk
 Asian lung fluke
 West Nile virus
Pathways of Introduction
How they get here…
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Aquaria
Aquaculture
Ballast water
Intentional introduction
Live bait
Live seafood
Aquascaping
Pathways of Introduction
How they are spread once there are here…
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Stowaways
Boats and equipment
Shipping crates
Recreational activities
Infrastructure maintenance
Field crews
Examples of Invasive Aquatic Plants in California
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Water Hyacinth
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Hydrilla
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Eurasian Watermilfoil
Giant Salvinia
Brazilian Elodea
Curly Leaf Pondweed
South American Sponge Plant
Characteristics of Invasive Aquatic Plants
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Form dense mats can clog entire lakes & waterways
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Interferes with commercial and recreational water navigation
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Displace and reduce the diversity of native aquatic plants
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Supports a lower abundance and diversity of invertebrates
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Less valuable food source for waterfowl
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Clogs water diversions and pumps
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Depletes dissolved oxygen levels
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Increased sedimentation
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Causes flooding
Water Hyacinth (Eichhornia crassipes)
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Grows in all types of freshwater habitats
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Vary in size from a few inches to over three feet tall
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Showy lavender flowers
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Leaves are rounded and leathery, attached to
spongy inflated stalks
Dark feathery roots with end caps
Hydrilla (Hydrilla verticillata)
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Submersed plant, can grow to the surface
and form dense mats
Stems are slender, branched and up to 25
feet long
Leaves are strap-like and pointed, grow in
whorls of four to eight around the stem
Leaf margins are distinctly saw-toothed
Tiny white flowers on long stalks
Potato-like tubers attached to the roots in the
mud
Eurasian Watermilfoil (Myriophyllum spicatum)
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Tolerates a wide range of water conditions and
often forms large infestations
Stems are reddish-brown to whitish-pink;
branched and commonly grow to lengths of six to
nine feet
Leaves are deeply divided, soft and feather-like,
about two inches long, and arranged in whorls of
three to six leaves about the stem
Flowers are reddish and very small, held above
the water on an immersed flower spike that is
several inches long
Giant salvinia (Salvinia molesta)
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Looks like free floating fern; stems
rootless, hairy, about 10 cm long
Leaves in threes, looks like two,
rounded to somewhat broadly
elliptical 2 cm long, upper surface
with 4-pronged hairs joined at the
tips (resembling an egg beater),
lower surface hairy
Brazilian Waterweed (Egeria densa)
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Submersed plant is rooted, occurs in streams,
ponds, springs, and lakes
Stems are usually a foot or two long, but can be
much longer
Leaves are strap-shaped, about one inch long,
1/4 inch wide and occur in whorls of three to six
around the stem
Leaf margins have very fine saw teeth
Flowers are on short stalks about one inch above
the water; have three white petals and are
about 3/4 inch across
Curly-leaf Pondweed (Potamogeton crispus)
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Stem is flat, reddish-brown and grows
from 1 to 3 feet long
Leaves are reddish-green, oblong and
about 3 inches long
Distinct wavy edges that are finely
toothed
Flowers are reddish-white and emergent
from a short stem
New Invader:
South American Spongeplant
 Many seeds & small seedlings move
easily.
 Spongeplant mixed with duckweed.
Red circles show spongeplant
seedlings.
 Seeds survive at least three years.
 First California infestation in Redding
and Arcata 2003.
 Outcompetes several other
aggressive water weeds, like water
primrose and parrots feather.
Center for Aquatic and
Invasive Plants
http://plants.ifas.ufl.edu
Examples of Invasive Fauna Species
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Asian Clam
Chinese Mitten Crab
New Zealand Mudsnail
Florida Watersnake (Nerodia)
Northern Snakehead
Asian Clam (Corbicula fluminea)
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Introduced in 1800’s for human consumption
High densities, out-competes native clams
Impairs water delivery systems by clogging
pipes, valves and sprinklers
Traps sediment, forms bars in agriculture
canals, alters flow
Possible cause for pelagic fish decline in the
delta
Bioaccumulation of toxins
Control:
 mechanical removal
 chemicals
Chinese Mitten Crab (Eriocheir sinensis)
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Intentional releases for human
consumption and/or via ballast
water
Clogs fish salvage facilities
Creates losses for fisheries
Threatens levee stability
Potential host for human lung fluke
Population cyclic, low at present
New Zealand Mudsnail
(Potamopyrgus antipodarum)
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Ken Davis
Distribution of the New Zealand mudsnail in California.
From New Zealand
750,000 NZMS per square meter
Competes for space and food
Ties up nutrients – not digestible
by most fish or birds, shell takes a
long time to decompose
Shells block pipes, filters and
grates
Development of biocontrols
underway
Southern Watersnake
(Nerodia fasciata)
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Native to southeastern US
Threat to CA native and federally listed giant
garter snake (Thamnophis gigas)
Eradication efforts in SoCal
Northern Snakehead
(Channa argus)
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Native to China, and possibly Korea and Russia
First discovered in MD in 2002
Introduced as food source and through aquarium trade
Voracious predator – decimate native fish populations
Primitive lung – can breath air and move short distances over land
Some successful eradication efforts
New Invaders to California
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Zebra mussel (Dreissena
polymorpha)
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Quagga mussel (Dreissena
bugensis)
Zebra and Quagga Mussel
What can you do…
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Become aware of AIS and plan your activities accordingly
Develop and implement actions to prevent AIS introductions
Report all suspected sightings of AIS to 1-877-STOP-ANS
Take an active role and spread the word about AIS…
Give us a call… (209) 946-6400
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Ronald Smith – AIS Program Coordinator
Jon Thompson – ISRAP/HACCP Coordinator
Louanne McMartin – Watershed Coordinator
Questions