Recent accomplishments of CDFW's scientific community
The tilapia skin is visible on the bottom of the bear's paw.
Veterinarians perform an ultrasound to check on the progress of the second bear's pregnancy.
Acupuncture needles assist with pain management.
After placing the second bear, the team moved the first bear to another location where another man-made den awaited.
CDFW staff work together to build a makeshift den for a soft release in Los Padres National Forest. A soft release involves putting the bear in a den to simulate hibernation, and leaving it to wake up on its own.
Two talented veterinarians, an environmental scientist and several dedicated staff members at the CDFW Wildlife Investigations Lab recently put their heads and their resources together to help heal a pair of adult bears that were badly burned in the Thomas Fire. The bears, which were treated at the same time as a young mountain lion with similar, less severe burn injuries, were released back to the wild last Thursday, after several weeks of intensive – and unusual – care.
CDFW Senior Wildlife Veterinarian Dr. Deana Clifford was acting manager of the Wildlife Investigations Lab in Rancho Cordova when the first bear – an adult female weighing about 200 pounds – was captured inside of a backyard aviary in the Ojai area on December 9. With CDFW Environmental Scientist Christine Thompson coordinating, CDFW Wildlife Officer Jacob Coombs darted the bear and local veterinarian Dr. Duane Tom evaluated its injured paws and overall condition. Thompson then conferred with Clifford, who determined the bear might have a chance at recovery if treated quickly. The bear was put into a trailer for the seven-hour transport to Rancho Cordova, where Clifford was waiting.
By the time the bear arrived, Clifford had already reached out to Dr. Jamie Peyton, Chief of Integrative Medicine at the UC Davis Veterinary Teaching Hospital, for help. Weeks earlier, Peyton, who works mostly on domestic animals, had mentioned to Clifford in passing that she had a particular interest in animal burns, and would be interested in helping wildlife if the chance ever arose.
Peyton created a homemade burn salve for the bears’ paws, and a process for sterilizing tilapia skin. Fish skin, which contains collagen, is often used by doctors in Brazil to bandage human burns. The technique is not yet approved by the Food and Drug Administration for use in the United States, and had not been tried on veterinary patients.
To help keep the tilapia skin in place, Peyton cut pieces to exactly match the size of the bear’s paws and then sutured them over the wounds while the bear was under anesthesia. Additional temporary wrappings, including rice paper and corn husks, were added, with the intention of stretching out the amount of time it would take for the animal to chew down to the fish skin bandage. “We expected the outer wrapping to eventually come off, but we hoped the tilapia would keep steady pressure on the wounds and serve as an artificial skin long enough to speed healing of the wounds underneath,” Peyton said. She also used acupuncture to aid the bear with pain management.
The original plan was for Peyton to come to the lab weekly to check on the bear’s progress. But within just a few weeks, two more burn patients arrived from the Thomas Fire. A second adult female bear, found relatively close to where the first one was found, was brought to the lab by Thompson on December 22. And on December 23, the young mountain lion arrived from Santa Paula. The experimental tilapia treatment was extended to the two newcomers as well.
Of the three animals, the mountain lion’s injuries were the least severe. Because of his young age, he was earmarked for placement in a wildlife rescue facility. The two bears were in much worse condition, with oozing wounds and, in some cases, paw pads that were completely burned off. But because the bears were older and stronger, the veterinarians hoped to return them to the wild if their injuries could be healed.
To complicate matters further, on December 28, during a routine burn treatment, Clifford’s team performed an ultrasound on each bear, and found that the second bear was pregnant. The quest to heal the mother-to-be was now a race against time.
“That was a game changer for us, because we knew it wouldn’t be ideal for her to give birth in confinement,” Clifford said. “We aren’t really set up to have a birth at the lab holding facilities, and we knew there was a high probability that she could reject the cub, due to all the stress she was under. We needed to get her back into the wild as quickly as possible.”
While Clifford and Peyton continued to focus on healing the animals’ injuries, Thompson started scouting out potential release locations. Since both bears needed to be transported back to Southern California, it was decided to try to return them at the same time – albeit not exactly in the same location – in order to make the best use of staff time and resources.
Both bears’ original habitat had been destroyed by fire, so Thompson scouted for two new locations that fit several parameters. The bears needed to be close to their home range, but not within the burn area, and near ample food and water sources. She also wanted to keep them as far away from each other as possible. “A lot of wildlife habitat was destroyed by the fire, and there are already a lot of displaced animals roaming around,” Thompson said. “So there’s a good chance that whatever location we choose is already occupied by other bears, but only they know exactly where that designated territory is. The best we can do is make an educated guess, and place them as deep into wild lands as possible.”
Taking the rapidly changing winter weather reports into careful consideration, the team chose Wednesday, January 17, as the target date to get on the road. That morning, Peyton came to the Wildlife Investigations Lab one last time and both bears were immobilized for a final treatment for their feet. Then the bears were placed into separate transport trailers for the long journey home. Simultaneously, in the Los Padres National Forest, Thompson and Tom spent the day digging dirt and moving logs to create a winter den for each bear.
“At this time of the year, most bears have established dens for the winter, but since these bears won’t have time to create a den, we hope to improve their chances of survival by creating a den for them so they have a home base and shelter right away,” Clifford explained.
The team arrived late Wednesday night, and both staff and bears were hosted overnight by the Ventura County Sheriff’s Department. Early on the morning of January 18, Clifford, Thompson, Coombs, Tom and their team drove the bears deep into the forest for the final leg of their journey. One at a time, each bear was sedated and carefully placed into her den, while the team finished constructing a shelter around the slumbering animal. The bears are about five miles apart, as the crow flies, and each is wearing a satellite collar so CDFW can monitor her movements and survival post-release. Staff also placed trail cameras near each den.
“We’re really hopeful that these novel treatments accelerated the healing for these bears and provided them the best odds of survival,” Clifford said. “It’s especially good to know that we’ve maximized the odds of survival for the cub on the way. We don’t know exactly when it will be born, but hopefully we’ll be able to monitor the movements of the mother via satellite, and that will give us an indication of how things are going.”
For Clifford, the entire experience wasn’t simply about saving the lives of two bears. The bigger picture involves the body of knowledge the experimental treatment provided – both to the Wildlife Investigations Lab team and to the UC Davis Veterinary Teaching Hospital.
“This treatment has the potential to be used successfully on all kind of burn patients, both domestic and wild,” Clifford said. “For us, at the Wildlife Investigations Lab, it’s been an invaluable experience because California’s changing climate means that we’re likely to see more wild animals impacted by catastrophic wildfires. By better understanding what resources are needed to care for injured wildlife and what treatment techniques increase healing speed, we can make the most informed treatment decisions, reduce animals’ time in captivity and provide guidance to other facilities caring for burned animals.”
CDFW photos. For more, please see CDFW’s Flickr photo album: Thomas Fire Bears.
Top photo: The first bear rests in her holding enclosure after her treatment is finished. The outer wrapping on her feet (made of corn husks) will delay her efforts to chew off the tilapia skin bandages underneath.
Scientists with the California Department of Fish and Wildlife (CDFW) and Oregon State University recently published the results of a population study on fishers (Pekania pennanti) in northern California and southern Oregon. Led by CDFW Wildlife Statistician Dr. Brett Furnas and three coauthors, CDFW Senior Environmental Scientist Richard Callas, CDFW Research Analyst Russ Landers and Dr. Sean Matthews of Oregon State University, the study produced the first-ever robust estimates of density and size of the fisher population in northern California.
“This is the first time we’ve come up with a solid number of fishers, which is a starting point for tracking and monitoring populations,” Furnas said. “One of the most important tools we have used so far to help this species is reintroductions, so now -- with a baseline established and ongoing surveys planned -- we’ll be able to see if the population is really rebounding over time.”
Fishers in northern California and southern Oregon represent the largest remaining population in the Pacific states. The species once ranged from the state of Washington southward through Oregon and California. Currently, fishers occupy only a small portion of their historical range in that region. In California, fishers are found in the northern areas of the state and a small, isolated population occurs in the southern Sierra Nevada Mountains.
CDFW and the U.S. Fish and Wildlife Service have been petitioned on several occasions to list fishers as threatened or endangered under their respective Endangered Species Acts.
In 2016, while considering fishers in the southern Sierra Nevada Mountains of California, the California Fish and Game Commission voted that the petitioned action was warranted in part, choosing to accept the petition in the context of the Southern Sierra Nevada Evolutionarily Significant Unit, and adopted findings to that effect, which were published on May 6, 2016. Although fishers are relatively well-distributed in northern California and in portions of southern Oregon, data from existing surveys and prior studies was used to estimate abundance. This information is critically important to assess the status of fishers and serve as a baseline for conservation efforts.
Furnas and his coauthors used data from camera traps, hierarchical modeling of detections and non-detections of fishers from the cameras, and information about fisher home range size to develop their estimate of population size. They estimated that approximately 3,200 fishers occur within the northern California and southern Oregon study area, with an average density of 5.1 to 8.6 fishers per 100 square kilometers.
Estimating the sizes of wildlife populations is challenging, particularly for species such as the fisher that are difficult to observe and occur over large areas. A final population estimate for the fisher would not have been possible without the cooperation of a variety of federal and tribal agencies, universities and private landowners who shared datasets that were combined to complete the modeling. With these data, Furnas and his coauthors demonstrated that estimating the population size of the fisher at large geographic scales is feasible. They also suggested that the methods used in their research could be used to estimate the abundance of other carnivores, including black bear, gray fox and coyote.
The study was published in the journal Ecosphere. More information / view publication
Brush habitats were created and put into Lake Perris to provide fish with habitat to feed and reproduce. The habitats will be completely submersed when the lake is filled to capacity.
The exposed lakebed gave CDFW fisheries biologists the opportunity to safely construct different kinds of habitat for the fish in Lake Perris.
Rock Reefs and Spawning gravel areas have been created and placed in more than 100 places around Lake Perris that will be utilized once the lake is returned to full capacity.
Rock Reefs constructed along the shore of Lake Perris, most about 1,000 square feet provide cover for juvenile fish and forage species.
135 Pipe Caves were constructed from PVC pipe and will provide spawning habitat for catfish.
Biologists created about 1,500 brush habitats in hundreds of locations on the banks of Lake Perris and in accessible locations further into the lake.
Biologists created about 1,500 brush habitats in hundreds of locations on the banks of Lake Perris and in accessible locations further into the lake.
More than a decade ago, Southern California freshwater anglers were disappointed to see a tried-and-true fishing spot dramatically affected by an emergency lake drawdown. Due to seismic concerns with the Perris Dam, California Department of Water Resources (DWR) officials deemed it necessary to reduce the water level at Lake Perris near Riverside by several thousands of acre-feet.
The drawdown exposed about 25 feet of bank around the perimeter of the lake. Since water was not going to be available for years while the dam was assessed and repaired, CDFW embarked upon a fisheries habitat mitigation project (funded by DWR) to create new fish habitat in the remaining water and the now exposed lakebed.
The project had two phases. The first was to immediately create fisheries habitat in the drawn-down portion of the lake in order to maximize use of the remaining water. The second was to build new habitats on the temporarily exposed areas, with the hope of benefitting both sport-fish species and anglers when the lake is eventually refilled.
After 12 years, both phases are nearly completed.
After the initial water level reduction, teams from CDFW and DWR began working to prevent the immediate collapse of the lake’s fishery. The initial work, which took three years, involved the creation and placement of about 400 fish habitats made of recycled Christmas trees and citrus limbs. The man-made shelters ensured the fish would have places to hide and reproduce.
After the initial triage, CDFW biologists began to place additional habitats into the remaining water of Lake Perris. These habitats, made of thousands of tree trunks, citrus limbs and whole tree stumps would eventually give the lake’s fish an additional 1,500 refuges for safety.
The citrus limbs were drilled with a ½” hole in the base and multiple limbs were tied together as compactly as possible and attached to a concrete block with polypropylene ropes to weigh them down. They were then placed strategically in different parts of the lake. These citrus habitats should provide cover for the warm water fish for at least 10 - 15 years.
Due to their bulk, increased buoyancy and weight, the single tree stumps were placed individually around the lake and weighted down with concrete blocks to keep them anchored.
Because the lake will be refilled to capacity once dam repairs are complete, it is important that the scientists are able to carefully track each habitat location. They worked in quadrants, placing 20 - 60 bundles into each to create “communities.” The grouped communities increase localized productivity of the warm water fish native to the lake and contribute to maintaining the warm water fisheries while the lake is in its reduced capacity. Each of the quadrant’s corners was marked with GPS, enabling scientists to record and monitor data specific to each location.
The second phase of the project was the implementation of a Fishery Habitat Plan for the exposed lakebed above the drawn-down area. The implementation of the plan is a requirement of the Lake and Streambed Alteration Agreement between CDFW and DWR.
As with the below-water work that had already been completed, CDFW scientists carefully planned what kinds of habitat to create, what materials to use and where to place them in the open, exposed lakebed in order to provide the best environments for fish when the lake was fully restored. Areas were selected for habitat placement based on accessibility, proximity to existing natural habitat directly affected by the water reduction, avoidance of areas utilized for construction activities, distance from swimming areas and consideration of boating hazards.
Multiple types of habitats were designed and installed in Lake Perris, including:
CDFW Photos. Top Photo: Citrus tree stumps, weighted down with concrete blocks to keep them anchored were placed individually around Lake Perris to create small habitats called communities.
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For more than a century, CDFW’s Trout Hatchery and Stocking Program has been providing recreational fishing opportunities to anglers throughout California. Today, the trout hatchery program is composed of 13 hatcheries, which oversee 20 distinct fish production programs to produce 17 strains, species and subspecies of trout.
McCloud River Redband Trout (Oncorhynchus mykiss stonei) is the latest addition to the CDFW’s production and release efforts. McCloud River Redband Trout is a unique sub-species of rainbow trout endemic to the upper McCloud River area of Shasta and Siskiyou counties of northern California. This fish has beautiful coloration and unique adult characteristics – a pronounced crimson lateral stripe, adult parr marks, relatively large black dorsal spotting, yellow-white hues on the underbelly and white-tipped fins.
The new production and stocking program for McCloud River Redband Trout at Mt. Shasta Fish Hatchery will focus on the upper McCloud River, including McCloud Reservoir. Given that stocking will occur solely within the historic watershed of McCloud River Redband Trout, the program is distinguished by CDFW as a Heritage Trout Production Program. A Heritage Trout is defined as a species of trout native to California, in its native habitat and area. This type of fishery represents the most natural form of aquatic habitat, species and angling opportunity available. Many anglers seeking additional challenges and goals will specifically pursue heritage trout fisheries.
While modern genetics management and conservation hatchery methods are utilized in the McCloud River Redband program, the hatchery-produced fish are primarily for recreational angling and not for release to areas containing wild and genetically pure McCloud River Redband Trout in their natural habitat. This ensures that the most wild populations remain in their native habitat and can continue local adaptation without hatchery influence. CDFW expects the McCloud River Redband Trout program to reach full implementation by 2019-20. The McCloud River Redband program demonstrates CDFW’s progress and commitment to conservation efforts and fisheries management.
CDFW trout hatcheries will continue to produce and stock several strains and species of trout statewide to promote trout angling opportunities, and contribute to the conservation of California’s native species and sub-species of trout. One of the next priorities for the department’s trout hatchery program will commence in 2018, and focus on advancing the Kern River Rainbow Trout program at CDFWs’ Kern River Planting Base.
CDFW Fish and Wildlife Technician Beau Jones stocking McCloud River Redband Trout in August 2017. CDFW photos by hatchery staff.
California’s recreational fishery resource provides a huge benefit to the state’s economy. In the latest issue (102-3) of the scientific journal California Fish and Game, Reid et. al tackles the difficult task of quantifying the economic value of California’s recreational red abalone (Haliotis rufescens) fishery.
Using data for the 2013 season at more than 50 sites in Sonoma and Mendocino counties, the authors used the travel-cost estimation method to determine a value. According to their findings, the 31,000 people who fish for red abalone provide an economic benefit to California of between $24M and $44M annually.
The lower figure was derived solely by determining the costs involved in driving to the fishing locations, while the higher figure considers the time spent on the fishing activity. The data reveal three dominant criteria used to select fishing sites: 1) the presence of a harmful algal bloom — and the resulting stricter fishing regulations — in Sonoma County; 2) protection from ocean swells; and 3) the presence of recreational conveniences such as restrooms and boat launches.
Determining the economic value of the red abalone fishery puts into perspective the importance of managing it for sustainability.
Other articles in this issue focus on management implications for California halibut (Paralichthys californicus) and Olympia oysters (Ostrea lurida).
Lesyna and Barnes report that California halibut reach physical maturity at different sizes and ages, depending upon location. Macroscopic examination of specimens revealed that, although all halibut were mature before reaching the commercial and recreational minimum legal size limit, central California halibut are larger and older by the time they reach physical maturity than their southern California counterparts.
Moore et. al studied the sexual development and symbionts of Olympia oysters (Ostrea lurida) that settled naturally on artificial clutches placed in San Francisco Bay. The results of the study suggest that Olympia oysters have the capacity to flourish when suitable habitat is available.
Collectively, these articles demonstrate the importance of studying natural resources for their consumptive and non-consumptive value.
According to California Fish and Game Editor-in-Chief Armand Gonzales, the articles provide critical direction for resource management. “It is therefore incumbent upon us as scientists, to keep working, keep studying and keep reporting what we see and find.
CDFW Scientific Aide Aimee Taylor prepares electrofisher to harmlessly catch Paiute cutthroat trout in North Fork Cottonwood Creek.
The extremely rare Paiute cutthroat trout (PCT). Photo by William Somer for CDFW.
Aimee Taylor and Senior Environmental Scientist Jeff Weaver electrofish PCT in North Fork Cottonwood Creek.
Jeff Weaver, USFWS Biologist Chad Mellison and others take genetic samples from the fish.
The project’s lead biologist, Bill Somer, and Chad Mellison transfer the trout from CDFW’s tank truck to cans for the ride to Silver King Creek, by pack mule.
The CDFW-FWS-USFS team packs pure PCT in milk cans through the Silver King drainage.
Bill Somer releases Paiute cutthroat trout into Silver King Creek, above Llewellyn Falls.
Team members measured each Paiute cutthroat trout caught at White Mountain.
The California Department of Fish and Wildlife (CDFW), U.S. Fish and Wildlife Service (FWS), and U.S. Forest Service (USFS) have returned a rare trout species to its home water after a 71-year absence.
In 1946, poachers were decimating the Paiute Cutthroat Trout (PCT), a species whose native range was limited to a nine-mile section of Silver King Creek (Alpine County). To ensure the species’ survival, the USFS and Eastern Packers Association translocated 401 of these fish to North Fork Cottonwood Creek in Inyo County’s White Mountains. This population has persisted in isolation from other forms of trout and has recently provided important restoration options for resource managers. None of this would have been possible without the foresight of concerned biologists seven decades ago.
The conservation history of this rare trout is complex. The initial “conservation” measure was entirely inadvertent. In the early 1900s, Basque sheepherders in the area caught and transported PCT into the previously fishless portion of Silver King Creek above Llewellyn Falls. This early within-basin transfer was the salvation of the PCT, since non-native species were later introduced below the falls. The falls prevented non-natives from reaching the habitat above and protected PCT from hybridization and competition.
The FWS listed PCT as endangered under the Endangered Species Preservation Act of 1966 – the precursor to the federal Endangered Species Act (1973). The species was down-listed to threatened status in 1975, in order to facilitate management and restoration and to allow regulated angling. In 1994, CDFW, FWS and USFS began developing a restoration plan to remove non-native fishes from Silver King Creek and return the PCT to its native waters. From 2013 to 2015, the partner agencies treated 11 stream miles of Silver King Creek and three tributaries below Llewellyn Falls with a fish toxicant, rotenone, to remove all non-native fish species.
The PCT population in Upper Fish Valley, an area of Silver King Creek above the falls, has been considered a primary source for restocking the recovery area. Unfortunately, that population was heavily impacted by the extreme 2012-2016 drought. During this extended drought, lack of snow cover resulted in the stream freezing almost solid during cold snaps. In order to offset the resulting population decline, the partner agencies caught 86 pure PCT in North Fork Cottonwood Creek. On August 23, 2017, the fish were planted back into Silver King Creek above Llewellyn Falls.
Agency staff met in the White Mountain Wilderness (Inyo National Forest) and, along with volunteers and pack mules, hiked from their campsite to North Fork Cottonwood Creek. There, the team used electrofishers to retrieve descendants of the fish moved back in 1946. The fish were hauled out by mule, put in a specialized transport truck, and driven approximately 100 miles to the Carson Iceberg Wilderness. Another mule team then hauled them back to Silver King Creek. Thanks to careful handling by the collection and transport teams, every fish survived the trip home.
Due to its limited habitat, the Paiute Cutthroat Trout has been called the rarest, but most recoverable, form of trout in the United States. With the most recent success of this partnership, and due in large part to the foresight of conservationists in the past, the future looks bright for this beautiful native salmonid.
Learn more on the Paiute cutthroat trout web page.
Photos by Joe Barker, courtesy of U.S. Fish and Wildlife Service, except as noted.
Liz Vandentoorn, from the Inyo National Forest Region 5 Center of Excellence, leads a pack mule team and state and federal scientists to North Fork Cottonwood Creek to capture Paiute cutthroat trout and return them to Silver King Creek.
If you’re an avid marine sport angler, you have most likely seen the smiling faces and brown polo shirts of California Recreational Fisheries Survey (CRFS) samplers. Since its inception in 2004, CRFS has grown into one of the state’s largest and most important survey efforts. Survey samplers are tasked with collecting data about both recreational fishing catch and effort.
Annually, CRFS samplers make direct contact with 68,000 fishing parties at over 400 sampling sites between the California-Oregon state line to the California-Mexico border. A separate but related telephone survey effort contacts an additional 26,000 anglers. A program of this large scale is necessary because recreational fishing effort and success rates are highly dynamic – a large sample size is needed to adequately estimate catch and effort. Recreational fishing effort is also very challenging to predict, as it can be affected by many factors (weather, gas prices, time of year, fishing seasons, etc.). But the recreational sector accounts for a significant portion of overall marine harvest, so it’s essential to collect that data to produce reliable estimates of harvest.
CRFS is part of a larger effort to estimate recreational catch and effort on the west coast and is integral to the national effort conducted by the National Marine Fisheries Service’s Marine Recreational Information Program. This partnership allows CRFS methods to be periodically peer reviewed by expert consultants throughout the country. This review provides certification that the methods meet or exceed national standards and fisheries management needs, and can recommend the use of new methods to address changing needs or to capture emerging fisheries.
There are three parts to the survey. The first is the field sampling component. This consists of in-person interviews conducted for four different fishing modes – beaches and banks, man-made structures, private/rental boats, and commercial passenger fishing vessels. Field survey questions are specific to catch and effort data during daylight hours at publicly accessible sites. The second part of the survey is the telephone survey. Anglers are randomly selected monthly through the state’s online Automated License Data System (ALDS) and asked about effort data (the number of fishing trips taken) at beach and bank sites. The telephone survey also collects data from private boats returning to sites not sampled during the field survey, and private boats returning at night. The third part of the survey is collection of data from commercial passenger fishing vessel logs. Captains submit this information for every trip, and the data is used together with field sampling data to estimate overall fishing effort.
All of this information is used in many ways. In addition to CDFW, the Fish and Game Commission and the Pacific Fishery Management Council use the data to:
How can you help? There are two ways! If you encounter a CRFS sampler in the field, please cooperate and answer the interview questions truthfully. Take the time to allow the sampler to examine and measure any catch. Recreational anglers, particularly those who fish frequently, are more likely to encounter CRFS samplers. Every fishing trip is unique — different target species, success rates, different locations, different gear, etc. — so we ask anglers, “Even if you have completed this survey before, please cooperate each time you are asked!”
Secondly, if you receive a phone call, please say “yes” to the CRFS telephone surveyor. Data collected through this telephone survey is used to estimate fishing effort that cannot be estimated any other way.
Personal contact information is always kept confidential, and the information that is collected becomes part of a public database. To learn more about the CRFS, access the database or download related flyers and brochures, please visit www.wildlife.ca.gov/Conservation/Marine/CRFS.
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