Menu
Contact Us Search

Science Spotlight

Science Institute News

rss

Recent accomplishments of CDFW's scientific community


Going with the Flow: CDFW’s Water Branch Keeps a Careful Eye on California’s Riverine Resources

Going with the Flow: CDFW’s Water Branch Keeps a Careful Eye on California’s Riverine Resources

A brownish-green river with a glassy surface flows through semi-arid land as two men fish from the rocky shore
Surveying Ventura River in Ventura County

A person in a black, full-body wetsuit floats, face-down, in a clear, shallow stream lined by forest and riparian vegetation
Snorkel survey in Hollow Tree Creek in Mendocino County

A young steelhead trout is barely visible, camouflaged against greenish-golden rocks in a stream
Hollow Tree Creek steelhead

Taking care of California’s fish and wildlife wouldn’t be possible without managing the resources upon which they depend. To that end, CDFW has an entire branch – and many scientific staff – dedicated to the scientific study, and planning and management of water resources.

Within the Water Branch, CDFW’s Instream Flow Program (IFP) is tasked with collecting and contributing data necessary to make all kinds of important management decisions about ecological function, fish rearing, spawning and migration and habitat suitability.

In the simplest terms, “instream flow” refers to the rate of the water running through a waterway in a natural environment. But when one considers all the interests competing for use of that water – fisherman, boaters, farmers, businesses, water districts, and fish and wildlife themselves – the complexity of the subject is evident.

Measured in cubic feet per second (cfs), instream flow can be measured at different times of the year in a specific location in a waterway. The fluctuations can tell scientists quite a bit about the ecosystem health of a watershed. While some watersheds have flowing water throughout the year and others are intermittent it is often the responsibility of water managers to distribute the water between uses. CDFW, a natural resource management agency, is faced with the complex task of identifying and recommending instream flows necessary for supporting natural resources. Determining instream flows are crucial so that aquatic, riparian, and terrestrial resources dependent on water will be considered and protected during water distribution activities.

Guided by the California Water Action Plan, the Public Resources Code and the Fish and Game Code, IFP staff conduct flow studies, collect field data, develop guidelines for quality assurance, conduct outreach and coordinate with other agencies and interested parties on program-related activities.

In the past year, some of IFP staff’s largest projects have included:

  • A flow study at the South Fork of the Eel Watershed, which supports threatened coho, Chinook and steelhead.
  • A study of 46 coastal steelhead streams (Ventura County to Siskiyou County) to develop flow criteria and evaluate historic flow trends.
  • A flow study to identify flow regimes that will protect endangered Southern California steelhead in the Ventura River.
  • Technical studies and final flow recommendations based upon the needs of South-Central Coast steelhead in Monterey County’s Big Sur River.
  • Ongoing training for IFP staff, to ensure that field studies in swift water are carried out safely.

To learn more about these specific projects, please download the link opens in new windowIFP’s 2017 Year in Review (PDF) document, available on CDFW’s website.

A Featured Scientist Q&A with the IFP manager Robert Holmes is also available on the CDFW Science Institute page.

CDFW photos. Top photo: IFP staff hold a planning meeting prior to a survey on the Ventura River in Ventura County


On the Trail of the Mysterious Sierra Nevada Red Fox

On the Trail of the Mysterious Sierra Nevada Red Fox

A trap made of small logs covered with pine and fir fronds is camouflaged in the snow between two tree trunks.
Camouflaged trap used to capture foxes for the study. CDFW photo by Jennifer Carlson.

A bright orange, bushy-tailed fox runs in snow toward dense forest
Sierra Nevada red fox bounds back to its native habitat after capture and study. CDFW photo by Scientific Aide Corrie McFarland.

The Sierra Nevada red fox has been the subject of intensified study by CDFW over the past decade. As they are notoriously tough to track and even tougher to trap, there are many unanswered questions regarding this elusive animal.

In an effort to better understand this state-listed threatened species, an ongoing research project seeks to capture and affix GPS tracking collars to them. The data collected will help biologists better understand the size and characteristics of the fox’s home range, its denning and resting areas, and its foraging habits.

The species has been outfoxing researchers for some time -- to the point where in the 1980s, it was presumed to have vanished forever from its historically occupied habitat in the Cascade and Sierra Nevada ranges. In March 1993, thanks to the then-emerging technology of infrared trail cameras, US Forest Service employees detected a single red fox in the Lassen National Forest.

That discovery prompted a wider study of foxes and other meso-carnivores in and around Lassen Volcanic National Park. In the late 1990s and early 2000s, Dr. John Perrine of the University of California, Berkeley, captured five individuals, primarily in the park, and placed radio collars on them to study their home range (both summer and winter), food habits and resting sites. Unfortunately, two of the collared individuals died within a year and none of the females reproduced during the course of the study.

Years later, CDFW launched a new study to determine the foxes’ current distribution in northern California and to address potential impacts on the species from activities including recreation and timber harvest. Initial efforts in 2008 used scat-detector dogs to survey portions of Lassen Volcanic National Park and the adjacent Caribou Wilderness. Then, from 2009 to 2011, trail cameras and hair-snaring devices were employed to survey high-elevation habitats in the Cascade Range from Mount Shasta to Lassen Peak. Yet foxes were only detected in the Lassen Peak area.

CDFW biologists have continued to survey for foxes with trail cameras, hair-snaring devices and scat surveys. Scats and photos are often obtained along Lassen Volcanic National Park and Forest Service hiking trails, because, like many other animals, red foxes frequent trails as they move through their territories. Analysis of the DNA contained in the collected scats and hair identified 22 individuals from 2007-2016. Some of these foxes are long-lived – samples collected over time from the same individual indicate that five of those individuals lived at least five and a half years.

CDFW efforts to capture and collar Sierra Nevada red foxes since 2013 were unsuccessful – until early February 2018. The nearly two decade-long dry spell came to an end at last when CDFW captured a Sierra Nevada red fox, a male that weighed about 10 pounds. It was captured in a “log cabin” style trap on National Forest land just outside of Lassen Volcanic National Park, near the town of Mineral. The fox was collared and released at the capture location, and CDFW biologists have been impressed by the distances he has regularly been covering since (five to six miles per day) despite the rough terrain and high elevation.

“Persistence played a large role in our success, because there are many days when we do not have any fox detections,” said CDFW Wildlife Biologist Jennifer Carlson. “We also ramped up our efforts this year by hiring two scientific aids rather than just one, which allowed us to literally double our efforts by putting more traps out across the study area.”

CDFW hopes to capture as many as four more red foxes this year. Scientists are using box traps, cage traps and a “log cabin” style trap that researchers have used in other states to capture both red foxes and wolverines. Capturing foxes is not an easy task given the cold temperatures and snowstorms, but as the Lassen population may only consist of around 20 individuals, it is imperative for the department to learn as much as it can about this stealthy animal.

For more information, please visit the Sierra Nevada red fox page.

Top photo: Senior Environmental Scientist Pete Figura and Senior Wildlife Veterinarian Deana Clifford release a red fox study subject. CDFW photo by Corrie McFarland



Recent Posts

  • Restoring Franks Tract Posted 3 days ago
    In the heart of California’s Sacramento-San Joaquin River Delta lies a 3,000-acre flooded island called Franks Tract. Before humans diked and drained Franks Tract to grow potatoes, grains, asparagus and corn, the island was part of a vast freshwater marsh. ...
  • CDFW Bands Together with NWTF to Benefit Wild Turkey Hunters Posted last week
    Tim Hermansen of CDFW carries a turkey holding box to CDFW’s Levi Sousa while John Davis clears the net. Derek Schiewek of CDFW holds a turkey while CDFW’s Laura Cockrell measures the tarsus. Recent efforts to determine the number of turkeys ...
  • Replenishing Southern California’s Abalone Populations Posted 3 weeks ago
    WARC diver Shelby Kawana assesses habitat at one of the CDFW red abalone stocking sites located off the coast of southern California. WARC diver Armand Barilotti assesses habitat at one of the CDFW red abalone stocking sites located off ...
  • CDFW Pilot Study Establishing Foundation for Enhanced Study of Porcupines Posted last month
    Porcupine1: NRVP participants Greg Moore, Mike Maulhardt, Charles Brown and Ben Smith volunteered to service and maintain porcupine stations at Red Lake Wildlife Area. Not to put too fine a point on it, but studying California’s porcupines hasn’t traditionally been ...
  • Sierra Nevada Bighorn: A 21st Century Wildlife Success Story Posted last month
    These pregnant females will bolster the population of a newly established herd as well as provide an infusion of fresh genetic material to helps ensure their new herd’s health and long-term survival. Outfitted with an ear tag and two tracking ...
Read More »

CDFW Science Institute logo