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.
Palisade High School, a twenty minute drive from where I live
in Colorado, has something unusual – a fish hatchery. When I
read about this, I had to visit the school to see for myself.
Razorback suckers (Xyrauchen texanus), the only fish raised at
Palisade’s hatchery, once lived throughout the Colorado River
Basin from Wyoming to Baja California, Mexico. As is
typical of many fish native to the western US, damming of
rivers, introduction of non-native sport fishes and irrigation
channels have taken a toll. The critically endangered fish is
still found in small and fragmented populations throughout the
Colorado River Basin …
Everyone boating in Lake Tahoe already goes through a process
of “Clean, Drain, Dry” protocols prior to launching to keep
invasive species out of the big, beautiful lake. But what about
other vessels in the lake like paddle boards, electric
surfboards, kayaks, and canoes? … For pristine
waters that have no invasive species, such as Echo Lakes,
Angora, and Fallen Leaf lakes, even Lake Tahoe is considered a
threat from the Eurasian watermilfoil, curlyleaf pondweed, and
Asian clams currently found in Big Blue.
After nearly two years of a collaborative effort led by the
Delta Stewardship Council’s Delta Science Program, the wait is
finally over. We’re excited and proud to present the final
2022-2026 SAA for the Delta. … Scientists, managers, and
those with a stake in the Delta were invited to participate in
two public workshops, four online surveys, and four review
periods and were engaged in various collaborative venues. The
collaborative process was a critical component of this SAA and
built on the success of the 2017-2021 SAA, which guided over
$35 million from the Council and its partners for
For the past 15 years, federal agencies have tried to subdue
growing populations of quagga mussels, an invasive species that
interferes with water infrastructure and threatens ecosystems.
Crews tried scrubbing the mollusks off equipment,
power washing them off boats and deploying chlorine and UV
lights to prevent them from settling in pipes. But the tiny
mussels have not only resisted all deterrents, they’ve clogged
cooling equipment, reduced water flow to hydropower and
even changed the water quality, making it less suitable for
A leading U.S. environmental conservation group has released
its annual list of the country’s most endangered rivers. The
Colorado River tops the list, but states across the nation must
address polluted, dry, and unhealthy rivers, according to the
list and accompanying report published today by American
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.
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
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
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
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.