Invasive species, also known as exotics, are plants, animals,
insects, and aquatic species introduced into non-native habitats.
Without natural predators or threats, these introduced species
Often,invasive species travel to non-native areas by ship,
either in ballast water released into harbors or attached to the
sides of boats. From there, introduced species can then spread
and significantly alter ecosystems and the natural food chain as
they go. Another example of non-native species introduction
is the dumping of aquarium fish into waterways.
Invasive species also put water conveyance systems at risk. Water
pumps and other infrastructure can potentially shut down due to
large numbers of invasive species.
The organism, responsible for the catastrophic decline of the
Sierra Nevada yellow-legged frog and 200 other species, emerged
from East Asia in the early 1900s and is spreading by the pet
trade and the expansion of global trade, according to an
international research consortium of 38 different institutions.
The U.S. Army Corps of Engineers has reached an agreement with
the Tahoe Regional Planning Agency to provide $1 million in
federal funding to help combat invasive aquatic species that
harm the health and clarity of Lake Tahoe.
The “triple threat” of invasive rodent species has made its way
to the edge of the delta, officials said, putting the state’s
fragile water infrastructure at risk. The California Department
of Fish and Wildlife said Tuesday that it had discovered the
nutria, a large rat-like mammal that inhabits wet, rural areas,
on agricultural land west of Stockton.
The destructive invasive swamp rodents known as nutria are
officially on the doorstep of one of the state’s most
critically important waterways. State wildlife officials
announced Tuesday that a nutria was killed on agricultural land
west of Stockton in San Joaquin County.
About the size of a beagle, they can quickly turn a lush green
marsh to a wasteland. … They are called nutria, and right now
they’re starting to spread through the waterways leading into
the Sacramento-San Joaquin Delta, the ecologically fragile
network of sloughs and rivers that functions as the heart of
California’s flood-control and water distribution system.
Last winter’s drought-busting wet weather was a boon for
reservoirs and parched landscapes, but not so much for some
invasive species in San Francisco Bay, according to a long-term
study by Tiburon-based researchers. All that fresh water
that poured into the bay was bad news for certain invaders,
which have turned up in droves in recent decades from around
the world, often in ships’ ballast water.
Tahoe Resource Conservation District is three years into a
long-term aquatic invasive species eradication project on the
Truckee River — and the progress is encouraging. TRCD is
working to eliminate Eurasian watermilfoil from a 3-mile
stretch of the Truckee River, starting above the Tahoe City dam
and continuing down to Alpine Meadows Road.
This tour traveled deep into California’s water hub and traversed
the Sacramento-San Joaquin Delta, a 720,000-acre network of
islands and canals that supports the state’s water system and is
California’s most crucial water and ecological resource. The
tour made its way to San Francisco Bay and
included a ferry ride.
Governors of 19 Western states are pressing the federal
government to do more to prevent the spread of damage-causing
invasive mussels from infected federally managed waterways.
… The governors say they’re particularly concerned about
the mussels reaching the Columbia River Basin, Lake Tahoe, and
the Colorado River Basin above Lake Powell.
For months, regional water officials were prevented from
recharging drought-depleted water basins in the San Gabriel
Valley and southeast Los Angeles County because they feared an
infestation of an invasive shellfish that could destroy local
Like a scene in a horror movie where the evil creature keeps
coming back, invasive green crabs in the Seadrift Lagoon at
Stinson Beach just won’t seem to die. … Green crabs are
native to Europe and were introduced in the early 1800s to the
East Coast of the United States, and finally made their way to
San Francisco Bay in the late 1980s, possibly via ballast water
There’s an invasion plaguing the coastal waters of Southern
California. Waves of tiny interlopers spark havoc at fisheries,
clog municipal water pipes and frustrate boaters who must
dislodge buckets of sea crud.
Estuaries are places where fresh and
salt water mix, usually at the point where a river enters the
ocean. They are the meeting point between riverine environments
and the sea, with a combination of tides, waves, salinity, fresh
water flow and sediment. The constant churning means there are
elevated levels of nutrients, making estuaries highly productive
With a blue bandanna tucked under his hat and draped
across his neck to protect him from the sun, Gordon Fidler of
Palm Desert walked slowly over the terrain at Joshua Tree
National Park, eyes peeled for tumble mustard – a weed invading
an area of Keys View and threatening the natural wildlife.
… Invasive plants – or weeds – create fire hazards,
crowd out native plants and consume water and nutrients,
depleting food sources for the habitat such as the desert
A troublesome invasive species is
the quagga mussel, a tiny freshwater mollusk that attaches itself
to water utility infrastructure and reproduces at a rapid rate,
causing damage to pipes and pumps.
First found in the Great Lakes in 1988 (dumped with ballast water
from overseas ships), the quagga mussel along with the zebra
mussel are native to the rivers and lakes of eastern Europe and
western Asia, including the Black, Caspian and Azov Seas and the
Dneiper River drainage of Ukraine and Ponto-Caspian
Pyramid Lake is now infested with ecosystem-altering Quagga
Mussels after state officials found six of the non-native
freshwater mollusks Thursday in a tunnel that connects the lake
with another body of water along the state’s water delivery
After several years of unrelenting hyacinth invasions each
fall, it’s as if someone has finally peeled back that green
shag carpet and returned Stockton’s rivers to its people. …
And there is a general sense that a coordinated effort by state
and federal officials — along with a bit of help from Mother
Nature — is starting to make a difference.
It was a good plan: Bring in hungry beetles that feed only on
nonnative salt cedar trees to get a handle on a hardy, invasive
species that was crowding riverbanks across the West and
leaching precious water from the drought-stricken region.
Two types of yellow-legged frogs, and a kind of toad found in
Yosemite National Park, won extra protection Thursday when
federal authorities declared nearly 3,000 square miles in
California’s Sierra Nevada mountains as critical habitat for
the endangered animals.
California wildlife agencies say the drought has pushed the
endangered Delta smelt close to extinction. State and federal
agencies announced Tuesday a joint effort to improve habitat
conditions for the fish.
Saying they wanted to go beyond what they’ve done in the past,
state officials resumed water hyacinth removal efforts at the
downtown Stockton waterfront earlier than normal on Wednesday
with the blessing of federal biologists.
For [J.D.] Richey and the anglers, it was a successful weekday
outing, resulting in a bounty of fish dinners to come. More
broadly, the scene put them smack in the center of yet another
Central Valley river conflict, one that pits “good” fish
against “bad” fish, farmers against anglers, and without enough
fresh water to allow them all to thrive.
When the Tahoe Keys were created in the 1960s they became Lake
Tahoe’s largest commercial marina. … It’s possible that no
one could have foreseen that those warm, shallow channels would
one day be home to Tahoe’s most dense population of invasive
Eleven years ago, it was a major threat to San Francisco Bay. A
fast-growing, non-native plant that spread in dense thickets up
to 7 feet tall was exploding out of control, overrunning
wetlands, threatening birds, wildlife and even the public’s
view of the water.
Water hyacinth, the invasive water weed that carpets San
Joaquin Delta channels in the warm season, choking out native
species, degrading water quality, blocking recreational boaters
and interfering with commercial ship traffic, holds promise as
The discovery of an invasive mudsnail downstream of the Table
Mountain Boulevard bridge in Oroville, has prompted state
officials to urge Feather River users to decontaminate
equipment. … Officials are also setting up decontamination
protocols to keep the mudsnails from entering the nearby
Feather River Fish Hatchery.
Tuolumne County has received a $70.4 million grant to restore
part of the Rim fire zone, build a plant that turns wood into
energy and building materials, and create a center for job
training and other services.
An invasive species of snail that is able to self-reproduce by
the hundreds and outcompete native species has been discovered
for the first time in Humboldt State University’s College
Creek, and there is no known method to stop its exponential
The Delta’s floating green menace has now forced the city of
Stockton to close its largest boat launch, another sign that
this year’s water hyacinth invasion is just as nasty — if not
more so — than last year’s.
Monday’s announcement was a blow for those hoping that an extra
$4 million dedicated to hyacinth control efforts and a more
aggressive schedule for applying herbicides would lead to
noticeable improvement in 2015.
A federal appeals court ordered the government Monday to
rewrite its regulations on ballast water discharges from ships,
one of the leading culprits in the spread of invasive species
across U.S. waterways.
[Gary] Rogers, 72, is a first responder of sorts in the war on
water hyacinth. He patrols the Delta several times a week,
investigating those backwater sloughs where the alien scourge
is known to incubate.
Montana, Wyoming, Washington, Oregon and Idaho are the only
states in the West still free of invasive quagga and zebra
mussels. State officials want desperately to keep the mussels
out of blue-ribbon trout streams and pristine mountain
The $250,000 plan, sponsored by the Tahoe Keys Property Owners
Association (TKPOA), released on Tuesday for comment, tackles
an issue that other methods during the past 25 years have
failed to address to remove non-native invasive species that
choke parts of the Tahoe Keys lagoons.
Federal agriculture officials are spending nearly $60 million
this year to help combat the beetles, bollworms and other bugs
that have the potential to wreak havoc on American crops, with
California and Florida taking the biggest share.
Reclamation has released for public review environmental
documents for the proposed zebra mussel eradication project for
San Justo Reservoir, the Hollister Conduit and the San Benito
County Water District’s distribution system. The proposed
treatment is to use potash which has been shown to be effective
in killing zebra mussels.
U.S. Interior Secretary Sally Jewell has released the initial
plan for a new wildfire-fighting strategy to protect a wide
swath of intermountain West sagebrush country that supports
cattle ranching and is home to a struggling bird species.
A 300-yard stretch of the Tuolumne River near Hughson shows one
of the many impacts of the ongoing drought. The river is thick
with water hyacinth, a plant that chokes the flow to the point
where it looks like you could walk across it.
The Tahoe Regional Planning Agency on Friday asked Nevada
lawmakers to support Gov. Brian Sandoval’s recommended budget
to fund a total of $750,000 a year to protect Lake Tahoe from
invasive aquatic species.
Government-sanctioned tests of equipment designed to cleanse
ship ballast water of invasive species are seriously flawed
because they don’t determine whether the systems will remove
microbes that cause gastrointestinal illnesses, scientists said
Goodness gracious, politicians and state officials are abuzz
these days about the water hyacinth problem in the Delta waters
around Stockton. … Which begs the questions: Where was this
fervent reaction in 2013? And 2012? And 2011? And 2010?
Recent storms have mostly cleared Stockton waterways that were
hijacked by hyacinth the past two months, but officials at a
standing-room-only town hall meeting Monday said it’s important
to stay focused on the future.
The lake of [Jay] Hall’s memory is dead, its salmon all but
vanished in the past decade – a collapse so swift that
fisheries biologists have likened it to driving off a cliff.
For a brief few decades, those biologists had turned this Great
Lake into a Pacific chinook factory, taking a wildly popular
sport fish from faraway ocean waters and setting it loose to
gorge upon the swarms of invasive alewives that had decimated
native fish species.
The earthquake and tsunami that devastated a large part of
Japan almost four years ago is still causing trouble, not only
for Japan, of course, but also for the Northwest coastline. The
biggest threat isn’t radioactive particles from the Fukushima
power plant meltdown, though some has recently shown up on this
side of the Pacific, but potential invasive species hitching a
ride on debris that’s been out in the ocean these few years.
State officials said the weather is playing a role in ridding
the delta of a stubborn water weed that has plagued Stockton’s
Waterfront, but added that the state is also upping its efforts
to finish off the pesky plant.
The Village West Marina in Stockton recently came up with a
possible solution to help weed out the growing water hyacinth
problem, but the San Joaquin County Sheriff’s Department put an
end to the plans for now, saying it breaks a harbor navigation
To John Laird, Secretary of the California Natural Resources
Agency: The hyacinth situation in parts of the California Delta
has become a disaster. The navigable part of the Calaveras
River is completely filled in with the pest as are Buckley
Cove, downtown Stockton harbor, Whiskey Slough, much of the San
Joaquin River and many other areas — this is just a sampling.
With Stockton’s water hyacinth invasion seeming to only get
worse, San Joaquin County legislators on Friday asked state
officials to request a “sustained funding source” from the
federal government to fight back against the prolific weeds.
The Bureau of Reclamation has released a report summarizing six
years of testing coatings to control the attachment of quagga
and zebra mussels to water and power facilities. … The
testing was conducted at Parker Dam on the Colorado
In a final effort to rid thousands of invasive fish from the
Presidio’s historic Mountain Lake and make room for native
species, biologists will use a standard fish-killing chemical
called rotenone, park officials said this week.
A project to suffocate Asian clams at Lake Tahoe’s treasured
Emerald Bay may be coming to an end this month, when divers
help remove about 5 acres of rubber matting being used to cut
off the species’ oxygen supply.
Asian Citrus Psyllids, an invasive insect, have been found in
Manteca and Lodi, according to San Joaquin County Agricultural
Commissioner Tim Pelican. … The psyllids pose no threat to
humans, but they can carry the huanglongbing disease, also
known as citrus greening.
For the second year in a row, despite state officials’ efforts
to control water hyacinth with herbicides as early as March,
another bumper crop is now making its annual fall push into
Stockton and other portions of the Delta.
This 24×36 inch poster, suitable for framing, explains how
non-native invasive animals can alter the natural ecosystem,
leading to the demise of native animals. “Unwelcome Visitors”
features photos and information on four such species – including
the zerbra mussel – and explains the environmental and economic
threats posed by these species.
This 24×36 inch poster, suitable for framing, explains how
non-native invasive plants can alter the natural ecosystem,
leading to the demise of native plants and animals. “Space
Invaders” features photos and information on six non-native
plants that have caused widespread problems in the Bay-Delta
Estuary and elsewhere.
The 24-page Layperson’s Guide to the Delta explores the competing
uses and demands on California’s Sacramento-San Joaquin Delta.
Included in the guide are sections on the history of the Delta,
its role in the state’s water system, and its many complex issues
with sections on water quality, levees, salinity and agricultural
drainage, fish and wildlife, and water distribution.