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.
A newly detected invasive mussel is posing a potential threat
to Lake County’s water bodies. The Lake County Water Resources
Department, and Watershed Protection District urge residents
and visitors to Clear Lake, and other Lake County water bodies,
to be aware and on the lookout for invasive golden mussels
(Limnoperna fortunei). The newly detected invasive mussel
(freshwater bivalve) found in several locations in the Port of
Stockton and in the Sacramento-San Joaquin Delta region. On
Oct. 17, the California Department of Water Resources reported
finding attached, adult mussels at a sample site location in
the Port of Stockton. Mussel specimens were sent to UC Davis
Genomic Variation Laboratory and confirmed to be golden
mussels, originally from China and Southeast Asia; the species
had not previously been detected in North America.
Colorado wildlife officials keep putting up geographic and
psychological barriers to the noxious water weed Eurasian
watermilfoil, and the voracious invader keeps busting right
through. The fast-growing water floater — the bane of
Colorado handlers for nearly two decades — now has been found
in Pueblo’s Fountain Lake, near the Interstate 25 and U.S. 50
intersection, and its outlet into the broader Arkansas River.
The announcement is the first major spread of milfoil in
Colorado since a 2022 invasion of Boulder Reservoir, and opens
up the southeastern part of the state to all sorts of
trouble.
A large, fast-breeding rodent that tears through wetlands and
crops has raised alarm among Solano County officials and
farmers. Nutria, which may grow up to 2 feet long and weigh 20
pounds, were discovered in the Central Valley as early as 2017,
after going undetected for 40 years in California. But recently
they’ve multiplied. State Fish and Wildlife efforts have
captured a total of 5,171 nutria across 10 counties, including
Stanislaus, Fresno, San Joaquin, Mariposa, Sacramento, Contra
Costa, Madera, Tuolumne and Solano. The fear is they will
migrate to other North Bay areas beyond the Suisun Marsh,
specifically into sensitive wetlands and watersheds, such as
the Napa-Sonoma Marshes Wildlife Areas, San Pablo National
Wildlife Refuge and San Francisco Bay.
The recent discovery of a new type of invasive mussel in the
Sacramento-San Joaquin River Delta is raising concerns that the
non-native species could cause major ecological harm and
inflict costly complications for the infrastructure California
relies on to deliver water across the state. … After finding
the golden mussels in O’Neill Forebay, state workers have begun
surveys to determine the extent of the infestation in the State
Water Project system, including the California Aqueduct, which
transports water pumped from the Delta to cities and farmlands.
The increased monitoring and maintenance that will be required
is expected to have an economic impact for the State Water
Project, increasing water delivery costs, said Tanya
Veldhuizen, manager of the Department of Water Resources’
Special Projects Section.
Known by a deceivingly healthy-sounding name —nutria — its
eating and burrowing ways can literally destroy natural wetland
systems if left unchecked. So far more than 500 nutria have
been detected since last year in the Suisun Marsh in the far
western Delta. “We’re very concerned,” said Krysten Kellum, a
spokesperson for the California Department of Fish and
Wildlife. “They are destroying our wetlands.” This foreign
creature has plenty of company in this 700,000-acre estuary.
More than 95 percent of the Delta’s fish and plants are
non-native. While the Delta may look outwardly bucolic, it is
one of the most altered places on earth. —Written by Tom Philp, editorial writer and columnist
with The Sacramento Bee
A new species of mussels discovered in California’s waterways
earlier this month could have massive ramifications for the
entire state if it’s not contained, the California Department
of Fish and Wildlife said Thursday. The California Department
of Water Resources discovered golden mussels, which are native
to China and Southeast Asia, while doing routine maintenance in
the Port of Stockton, marking the first-ever appearance of the
species in North America. The mussels likely reached California
by clinging to the bottom of an international vessel, Fish and
Wildlife officials said, announcing the
discovery. The department said the
species poses a significant, immediate threat to the ecological
health of all of California’s waters, not just the
Sacramento-Joaquin Delta where it was discovered.
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.
