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
then multiply.
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 Department of Water Resources (DWR), California Department
of Fish and Wildlife (CDFW), and California State
Parks have confirmed presence of the invasive golden
mussel at Pyramid Lake in Los Angeles County
and Silverwood Lake in San Bernardino County. These lakes
are the southernmost State Water Project (SWP) reservoirs
where golden mussels have been detected. The invasive
species was recently discovered during a routine water test by
DWR; in response, State Parks has updated Silverwood
Lake’s boat inspection protocols, effective immediately.
Invasive golden mussels may have been spotted in Butte County
last week, raising concerns about the potential impact on local
water resources. A recent watercraft inspection at the
Thermalito North Forebay prevented what is suspected to be the
invasive species from entering the water, marking only the
second time they have been seen at the site. … The
Oroville facilities, including the Thermalito Forebay,
Thermalito Afterbay, and Lake Oroville, supply water to roughly
23 million Californians.
Wild pigs roam on the loose in 56 of California’s 58
counties. … [E]specially in warm weather, pigs love to hang
out in streams and ponds. “They’ll wallow in the water
sources, which is one of the types of damage they do,”
[Santa Clara Valley Open Space Authority Natural Resource
Technician David] Mauk said. “[It] harms the sides of banks,
causes a lot of erosion, damages the vegetation in those
riparian areas and really destroys the habitat for other
animals that want to use those, like the California red-legged
frog.”
Water is a driving force in the American West, and today it’s
at risk more than ever. Not just from overuse, not just from
megadrought, but from minuscule invaders that pose a nearly
unstoppable threat to the region’s rivers, lakes, dams and
reservoirs. …The mollusks’ westward sweep recently crossed a
feared Rubicon when Colorado discovered zebra mussels in its
portion of the Colorado River system, an imperiled lifeline to
40 million people.
Golden mussels pose a growing threat to California’s waterways
and infrastructure. … Dr. Pam Marrone is the co-founder of
the Invasive Species Corporation, a Davis-based company seeking
to find environmentally-friendly solutions to control invasive
species. The company created a product called Zequanox that
successfully eradicates non-native zebra and quagga mussels,
and is now adapting that product for the newest aquatic
invader. Marrone spoke with Insight Host Vicki Gonzalez about
her experience in biocontrol, and her company’s work to get rid
of the golden mussel for good.
As highly-invasive golden mussels spread across California
waterways, officials are urging boaters to take thorough
precautions to avoid introducing the species to unaffected
waters over the busy Labor Day weekend. It’s also a good idea
to contact the body of water you plan to visit to get the
latest information before heading out there, according to the
California Department of Fish and Wildlife. … The freshwater
mollusks threaten the state’s water infrastructure by clogging
pipes and power systems.
The scientist traipses to a pond wearing rubber boots but he
doesn’t enter the water. Instead, Brad Hollingsworth squats
next to its swampy edge and retrieves a recording device the
size of a deck of cards. He then opens it up and removes a tiny
memory card containing 18 hours of sound. … [N]o croaking
from the invasive bullfrog, which has decimated the native
red-legged frog population over the past century. It was
another good day in his efforts to increase the population of
the red-legged frog and restore an ecosystem spanning the
U.S.-Mexico border.
As part of restoring the Bolinas Lagoon watershed, the
Watershed Stewards Program, San Francisco Bay Area Inventory &
Monitoring Network, Point Reyes National Seashore, and Audubon
Canyon Ranch partnered for a volunteer event at Volunteer
Canyon Creek. With over a dozen volunteers we removed hundreds
of pounds of invasive Cape ivy from the banks of the creek, a
sensitive tributary of Bolinas Lagoon. Bolinas Lagoon, a
Wetland of International Importance, supports large numbers of
harbor seals and migratory birds, and has served as the heart
of surrounding communities for thousands of years.
Local officials are doubling down on efforts to protect Lake
Sonoma from a tiny invasive mollusk with a massive destructive
potential. At this week’s Sonoma County Board of Supervisors
meeting, the board unanimously approved a plan to extend the
Lake Sonoma Mussel Infestation Prevention Program, aiming to
keep quagga and zebra mussels out of the
reservoir. The board’s official resolution ratifies and
approves Sonoma Water’s application for a state grant to fund
two more years of mussel-prevention measures at Lake Sonoma. In
plain terms, the county is trying to secure about $400,000 in
state funding to continue boat inspections, public outreach,
and early-detection monitoring on the lake through 2027.
… [F]or wetland biologists and others with a stake in the
health of the surrounding Sacramento-San Joaquin Delta, the
largest estuary on the West Coast, the birds represent the
latest – and an exponentially growing – threat to the few
remaining wetlands left in California. … Mute swans
also feed gluttonously on submerged vegetation, destroying the
plant life on which other native wetland species depend. … A
measure before the state Legislature aims to allow hunters and
landowners to shoot the swans for the next five years to try to
bring their numbers down to more manageable levels in the
Sacramento-San Joaquin Delta and beyond.
A few strands of thin, feathery, green plants growing under the
dock didn’t catch anyone’s attention last spring. But those
strands spread quickly and within months the lake’s calm waters
were tangled in mats of the feathery Eurasian watermilfoil, an
aggressive aquatic plant that grows quickly and clogs
everything in its path. … This isn’t just an isolated
incident; it’s happening across California. Aquatic invasive
species are spreading faster than ever, infesting our ponds,
creeks, reservoirs, lakes, and rivers. Now is the time to learn
about aquatic invasive species; what they are, how they spread,
and what we can do to stop them. When we understand the issue,
we can make smart choices and protect California’s waters.
Several Colorado Democrats are using the recent detections of
zebra mussels in the Colorado River to push for implementation
of key provisions in the Expanding Public Lands Outdoor
Recreation Experiences Act. The EXPLORE Act, as it’s more
commonly known, passed in December 2024 and contained multiple
bills around improving public land access and conservation,
including the aptly named “Stop the Spread of Invasive Mussels
Act.” The law gave new authorities to the U.S. Department
of the Interior and U.S. Department of Agriculture to respond
to and monitor aquatic invasive species.
… American bullfrogs are not native to the Western US. Humans
brought them to the region more than a century ago, largely as
a food source. And in the years since, the frogs — which are
forest green and the size of a small house cat — have
multiplied dramatically. … They escaped from farms and, with
other accidental and intentional introductions, proliferated
until they were common in ponds, lakes, and other water bodies
throughout much of the West, including Arizona, California, and
the Pacific Northwest. … While western states have rivers and
wetlands, permanent warm waterbodies weren’t common until the
spread of agriculture and the need for irrigation. … Now
ponds, reservoirs, and canals — which bullfrogs love — are
everywhere.
With golden mussels now confirmed
in California waterways, the focus has shifted from
detection to defense. On Monday, local leaders toured the Port
of Stockton—where the invasive species was first spotted in
North America just 10 months ago—to highlight the growing
efforts to stop the mussels before they cause widespread damage
to critical water infrastructure. … [Rep. Josh] Harder and
other California Democrats are backing a $15 million bill in
Congress to create a task force that would research, prevent,
control and eradicate golden mussels. The bill is currently in
committee. Meanwhile, scientists at a Davis-based lab are
already testing a potential biological solution.
A new aquatic invader, the golden mussel, has penetrated California’s ecologically fragile Sacramento-San Joaquin Delta, the West Coast’s largest tidal estuary and the hub of the state’s vast water export system. While state officials say they’re working to keep this latest invasive species in check, they concede it may be a nearly impossible task: The golden mussel is in the Golden State to stay – and it is likely to spread.
In the vast labyrinth of the West
Coast’s largest freshwater tidal estuary, one native fish species
has never been so rare. Once uncountably numerous, the Delta
smelt was placed on state and federal endangered species lists in
1993, stopped appearing in most annual sampling surveys in 2016,
and is now, for all practical purposes, extinct in the wild. At
least, it was.
This tour guided participants on a virtual journey deep into California’s most crucial water and ecological resource – the Sacramento-San Joaquin Delta. The 720,000-acre network of islands and canals support the state’s two major water systems – the State Water Project and the Central Valley Project. The Delta and the connecting San Francisco Bay form the largest freshwater tidal estuary of its kind on the West coast.
Nutria are large, beaver-like
rodents native to South America that have caused alarm in
California since their rediscovery along Central Valley rivers
and other waterways in 2017.
The growing leadership of women in water. The Colorado River’s persistent drought and efforts to sign off on a plan to avert worse shortfalls of water from the river. And in California’s Central Valley, promising solutions to vexing water resource challenges.
These were among the topics that Western Water news explored in 2018.
We’re already planning a full slate of stories for 2019. You can sign up here to be alerted when new stories are published. In the meantime, take a look at what we dove into in 2018:
Sixty percent of California’s developed water supply
originates high in the Sierra Nevada mountains. Our water
supply is largely dependent on the health of our Sierra forests,
which are suffering from ecosystem degradation, drought,
wildfires and widespread tree mortality.
We headed into the foothills and the mountains to examine
water issues that happen upstream but have dramatic impacts
downstream and throughout the state.
GEI (Tour Starting Point)
2868 Prospect Park Dr.
Rancho Cordova, CA 95670.
For more than 100 years, invasive
species have made the Sacramento-San Joaquin Delta their home,
disrupting the ecosystem and costing millions of dollars annually
in remediation.
The latest invader is the nutria, a large rodent native to South
America that causes concern because of its propensity to devour
every bit of vegetation in sight and destabilize levees by
burrowing into them. Wildlife officials are trapping the animal
and trying to learn the extent of its infestation.
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
natural habitats.
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
Sea.
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.
