Featured Scientist

Travis Tanaka on a boat sampling “slime eels”


Travis holding a California Halibut

Travis Tanaka is an environmental scientist with nearly two decades of experience working for CDFW. As a marine scientist with the Marine Region based out of the Monterey office, his primary responsibilities include monitoring the California halibut and Pacific hagfish fisheries, as well as collecting data to help manage their take.

Where did you grow up?

Paso Robles. Growing up in Paso really didn’t influence my future with CDFW or my choice to be a consumptive outdoor enthusiast. My influences came from my father and grandfather. My father taught me to be a hunter and responsible gun owner at a young age. My grandfather was a commercial fisherman and introduced me to fishing for various groundfish species. He taught me to appreciate our ocean’s resources.

What led you to a career in marine biology?

While going through school, I wanted to pursue a career in wildlife management or resource law enforcement. However, my path changed following a college lecture where the professor spoke candidly about upcoming job market opportunities and the future of what we might expect regarding job pursuits within the field of wildlife management. He said the reality was that we would find a lack of work in wildlife management, but that there would be upcoming needs in marine science. After that I began taking extra coursework in marine science and fisheries. Since I’d grown up fishing with my grandfather, I already had a vested interest in fisheries and so taking additional coursework was easy. I had to rethink my interest in resource law once I realized I wouldn’t be able to pass the vision exam.

Tell us about your current research.

I am a staff member on the Northern/Central California Finfish Research and Management Project where we monitor and conduct research on state-managed Finfish species (e.g. California halibut, surf perch, smelt and Pacific hagfish.) My role is to work on California halibut and Pacific hagfish.

For halibut, I monitor the fishery within Monterey Bay. This includes sampling the Monterey area commercial hook-and-line fishery for length distribution and age composition. Early on, I used to go to recreational launch sites and sample the halibut catch from sport anglers. The California Recreational Fisheries Survey (CRFS) program has a great handle on the recreational fishery now, so I put my focus on the commercial end. I also lead the processing for all halibut otoliths our project collects through sampling for ageing. Otoliths, also known as ear bones, are a hard, bony structure important to the fish’s sensory system. Each year, the fish will add a layer, similar to tree rings. I am one of two readers of all halibut otoliths sampled by CDFW staff. To date, we have aged 4,000 California halibut. This age-at-length dataset is one of several datasets that were incorporated into our latest stock assessment. Our project has been collecting halibut data since 2007.

In 2008, I began sampling the hagfish fishery out of Moss Landing to monitor and increase our knowledge of this remerging fishery. I developed a count-per-pound metric to sample live hagfish at the dock. Live hagfish are impossible to measure due to their movement and slime production. Hagfish can’t be sexed externally. To get an estimate of average weight or size, we randomly fill a bucket with hagfish, weigh the bucket and then count back the contents. If this is done repeatedly throughout the tank, we can develop an estimate for average weight. If the average count number goes up, then the fish are smaller per count, and vice versa. The ideal count is around four fish per pound, based on market demand. We then document the average size of retained hagfish and collect life history information, as well as information on the market and its participants.

During a short period in the early 1990s, the Pacific hagfish fishery in California flourished to satisfy an export market for hagfish skins where they were used to create expensive leather-like products, such as boots, bags, wallets and purses. However, a market-induced crash later occurred, and the fishery went dormant. But by 2007, a renewed market demand emerged for the harvest of live hagfish for use as human food.

Part of my job also involves working with fishermen interested in designing new harvest gear. Recently, I worked with fishermen who wanted to use barrels as a new trap type for the take of hagfish. After the fishermen secured experimental gear permits, our project evaluated their new gear design. With assistance from a colleague, we performed the necessary observation trips to collect data on interactions and bycatch. At the same time, we also collected lab samples to document sex ratios and the spawning maturity of hagfish caught by these traps. Once all of the results were in, we approved their new trap type that will improve quality-of-catch, reduce the number of traps on the seafloor, and ultimately be a viable option to existing trap gear.

What are Pacific hagfish?

Pacific hagfish are primitive, spineless, deep-sea fish that lack jaws, true eyes or a stomach. They live in muddy sea floors. Hagfish dine by scavenging dead or dying fish and marine mammals. They enter their prey through any existing hole or orifice they can find, or by creating a new hole via their two pairs of rasping jaws. Once inside, they tear the flesh from the carcasses as they devour their prey from the inside out. When stressed, their defensive mechanism is to overwhelm any prospective predators by exuding a thick viscous slime. This behavior is the reason hagfish are commonly called “slime eels.” Today, Pacific hagfish are caught and sold for human food, and much of the harvest is shipped to markets overseas.

What is a typical day like for you at work?

It depends on if my work day is during my field season or not. My halibut field season runs approximately May-October. Hagfish work is year-round but is significantly slower in the winter. During the field season, halibut sampling occurs in the morning and then I spend the afternoons in the office editing commercial fishing receipts, entering data, or processing halibut otoliths for ageing. Local hagfish sampling occurs in the morning. Once per month I travel to Morro Bay and Port San Luis to sample the Pacific hagfish fisheries in those ports. During the halibut off season, the average day is spent in the office working on the backlog of halibut otoliths, keeping up with landing receipt editing or addressing any pending issues. I spend a significant amount of time answering questions from commercial fishermen and recreational anglers.

What is the most challenging aspect of your job?

The most challenging aspect of the job, for me and for many others in CDFW, is balancing the needs of the resources (halibut and hagfish) with the needs of those people that use it. Within the group that utilize a fishery, there are often conflicts due to allocation between the recreational and commercial sectors (although not for hagfish, for which there is no recreational fishery). Thus, I am required to spend a significant amount of time answering questions from commercial fishermen and recreational anglers over a broad range of marine resources questions. As a CDFW environmental scientist, I must consider and balance the ramifications and consequences (biological, economic, social) of regulations and management actions.

Tell us something about yourself that many people would be surprised to learn.

It’s not really a surprise, but if I were not a CDFW scientist, I would be working as a commercial fishermen and hunting guide. I have also created some fishing tutorial videos on “Recreational Crabbing” and “Rockfish and Lingcod Fishing Tips and Tricks.” All are now posted on CDFW’s website and have nearly 40,000 views!

Media contact: Carrie Wilson, Communications, (831) 649-7191

Photos courtesy of Travis Tanaka. Top Photo: Travis sampling "slime eels".

Scott Harris participates on fish survey on the Middle Fork Eel River. CDFW Photo by Amanda Ekstrand.

Scott L. Harris is an environmental scientist with CDFW’s Northern Region, based in Mendocino County. Scott is responsible for monitoring and managing salmonid populations in the Eel River and Mendocino coast watersheds as part of the North Central District Salmon and Steelhead Management Project, a multi-faceted effort funded through the Sport Fish Restoration Act (SFRA). His fieldwork includes counting adult salmon and steelhead through spawning ground surveys and ladder counts at the Van Arsdale Fisheries Station (VAFS), counting juvenile salmonids migrating to the ocean and determining resident trout distribution in the Mendocino National Forest. Much of his time is spent at the VAFS fish ladder studying the biological effects of water releases from the Potter Valley Project (PVP). He also consults on fish passage issues, evaluating man-made structures (fish ladders, etc.) at road crossings to determine whether they are damaged, blocked or in need of cleaning, and whether the design is adequate to meet the need.

What or who inspired you to become a scientist?

The “what” is water. I am fascinated with water, salt or fresh. I grew up in Southern California and spent most of my time at the beach. When I was about 10, I was instantly hooked on the ocean when I first put a mask on and saw what was taking place under the waves. At about the same age, I found a local stream and was mesmerized by the number of animals that lived in and around that stream. Then came my love affair with PBS, NOVA, Wild Kingdom, the local library, etc. I’m guessing a lot of folks went through a similar progression.

The “who” probably started with Carl Sagan, Marlin Perkins (and, of course, Jim Fowler, Perkins’ assistant), my friend’s mom (a science teacher) and my dad (an engineer). Today I am surrounded by many colleagues who feed my interest in science and I would bet these folks are inspirational for many others, young and old.

My fascination with water continues today with my job. However, my work with the department requires the understanding of the physical aspects of water, not just the biological aspects. In stream restoration, it is necessary that one understands hydrology and fluvial (movement of sediment in water) processes.

What is a typical day like for you at work?

If there was a typical day, I would probably quit! There are days when I am greeted at my door by hunters that need a bear or deer validated. When a hunter takes a deer or bear, the animal must be reviewed and then some paperwork is completed indicating that the take was legal. In addition, a tooth must be extracted from bears. The tooth is used to determine age and this information is used as a tool in management of our black bear populations. Sometimes I’m asked to pull a bear tooth in the Safeway parking lot or at the gas station. This is not exactly fisheries but I absolutely believe I am part of a team. Typically, if I receive a call before 9 a.m., I know my day will change and that someone needs help. Many days include a wild card. I wouldn’t have it any other way!

I am one of the lucky ones. During the year, I spend 90 percent of my time in the field. So, 90 percent of the year, I leave my office excited and with a smile on my face, ready to learn something new or hopefully teach someone something new.

What is your favorite species to interact with or study?

For those who know me, they know how important herps and birds are to me. I bring that knowledge to many of my colleagues. However, there are two species that I have a special fondness for: The Middle Fork Eel River summer Steelhead and the Pacific Lamprey.

We conduct an annual free dive/snorkel survey on the Middle Fork Eel River that was named the “Death March” 30 or more years ago. This 26-mile, five-day survey is conducted in the Middle Eel/Yolla Bolly Wilderness located in Trinity and Mendocino counties with the intent to enumerate adult summer Steelhead. Dozens of department employees have been on the Death March over the years and I guarantee that they have yet to forget it. This annual survey began in 1966.

In 2009, I took over the activities at the Van Arsdale Fisheries Station located in the upper Eel River. Through our activities there, Pacific Lamprey became a target species for study. I have been collaborating with two people, Damon Goodman with the U.S. Fish and Wildlife Service and Stewart Reid with Western Fishes, both of whom are known for their background and expertise on Pacific Lamprey. We have all learned some amazing things about Pacific Lamprey. There has already been one “white” paper written from this work and I believe there are at least another two in the making.

What aspect of working on monitoring salmonid populations is the most challenging?

The projects that are most challenging are typically those with numerous stakeholders or interested parties. I have been involved with the Willits Bypass for decades and this project has seen multiple agencies and interested parties over time. Keep in mind, the Willits Bypass was started in 1955, so the number of interested parties could be considered myriad. Another project with a high number of interested parties is the PVP. With the Federal Energy Regulatory Commission relicensing effort underway for the PVP, things are getting interesting.

What is the most rewarding project that you have worked on for CDFW?

There are a few projects that come to mind, but the one that I will tell you about is more about how I have volunteered my time as a mentor. About 10 years ago, a neighbor introduced me to her son, Bryan. Bryan needed a science fair project. Before we decided on a project, I thought it would be good to involve Bryan in some of the fieldwork we conduct. So, he ended up getting a taste of salmon spawning ground surveys, juvenile outmigrant trapping, backpack electrofishing – he even participated in the infamous Death March.

The project we decided on was, to say the least, controversial. The title of the project was “Why is there no water in Alder Creek.” And yes, this project had everything to do with the effect of pot growing on aquatic resources. We conducted the fieldwork on weekends due to Bryan’s school schedule and we worked on maps and tables in the evenings. This project led to numerous field visits with department enforcement and Bureau of Land Management enforcement. Things got a little hairy in the field. It also led to a few threats over the phone. The bottom line is, Bryan’s project won first place at the state level and he even got to have lunch with retired Governor Deukmejian. I remain in touch with Bryan to this day, I suppose, as a father figure.

What is the most challenging aspect of your career as an environmental scientist?

For myself, and probably for most of us in the department who conduct monitoring, research and habitat restoration, it is resources. Not having resources (money) to implement more of what we are already doing is maddening. The challenge is to be OK with so little help.

If you had free reign and unlimited funding, what scientific project would you most like to do?

In, at least, our state’s three largest rivers (Sacramento, Klamath and Eel) I would like to see aquatic habitat (rivers, estuaries, lagoons, vernal pools, etc.) restoration of every conceivable type take place, and as quickly as possible. With the implementation of the restoration would come monitoring the effectiveness of the implementation by evaluating the response by plants, animals and the physical environment.

Any advice for people considering careers in science or natural resources?

Certainly, education plays a key role when it comes to our natural resources and science. Education also includes get involved in internships and/or volunteering. I have mentored 15 AmeriCorps members, two of whom went on to get doctorate degrees in fisheries ecology.

Top photo: Scott Harris hoists a bucket during a fish rescue on Feliz Creek. CDFW photo by Derek Acomb

Alisa Ellsworth holds a newly-collared bobcat for the Eastern Sierra Bobcat Project.


Alisa Ellsworth and crew working on Fish Slough Ecological Reserve restoration project.

CDFW Senior Environmental Scientist Alisa Ellsworth supervises the Inland Desert Region’s Northern Lands Program. Based out of the Bishop office, Alisa oversees 10 employees who perform a wide variety of activities including land acquisition planning, coordinating mitigation for incidental take, and managing over 120,000 acres of state ecological reserves and wildlife areas in Inyo, Mono and San Bernardino counties.

A Central Valley native, Alisa grew up in Visalia. She attended both undergraduate and graduate school at Fresno State, where she completed a bachelor’s degree in botany in 1993 and a master’s degree in biology in 1995. Her thesis focused on vernal pool ecology in Madera County.

What inspired you to become a biologist?

My interest in science first started in high school when I had to do an insect and plant collection for my biology class. I really enjoyed learning how to identify things in nature. When I started college, I was naturally drawn to biology courses and my path was set. I met a group of people that liked to go out botanizing and birding on the weekends and a whole new world opened up for me.

My first wildlife job was in 1992 with Pacific Southwest Research Station, estimating the density of spotted owls in Sequoia National Park. This is where I learned how to hike at night using a compass and topographic map, as there weren’t GPS units back in those days. The work also involved gathering vital rate data (reproduction and mortality) as well as characterizing diets from regurgitated pellets. In 1993, I spent an amazing summer working for the US Forest Service. I hiked all over the Sierra National Forest, mapping vegetation types and looking for rare plants.

How did you come to work for CDFW?

I worked as a scientific aide for the Habitat Conservation group in the Central Region for a year and a half when I was in college. After I graduated, I began working as a private consultant until 1996 conducting rare plant surveys, wetland delineations and revegetation projects. Around that time, I caught the travel bug and applied for a research assistant position focused on field studies of the guanaco, a South American wild camelid related to the llama. This took me to Torres Del Paine National Park in the Patagonia region of southern Chile, where I worked on guanaco reproductive strategies, spacing strategies and movement. We radio collared young guanacos (called chulengos) and monitored for survival and cause-specific mortality. This involved watching a mother give birth to her baby and then soon after running in and grabbing the baby and quickly putting a radio collar on it. Most of the mothers were pretty mild mannered, but one tried stomping on us and spit all over us, which was quite smelly!

Afterward, I joined the Peace Corps and stayed in Ecuador until 1999, working on environmental education projects in schools. When I returned to the United States, I worked briefly as a consultant again, and then took an associate biologist position with Caltrans in Fresno. When a position opened up in CDFW’s Bishop office, in the streambed alteration agreement program, I jumped at it. I was hired in 2001 and have never wanted to leave Bishop since.

Over my career with CDFW, I have managed the X9B and X9C deer zones, the Owens Valley tule elk zones and the White Mountain bighorn sheep hunt zone. I have collected and analyzed wildlife population data for upland game birds, mule deer, tule elk and Nelson bighorn sheep. I’ve provided harvest recommendations and direction for population management of those game animals. Since 2008, I’ve been with the Lands program, working on acquisition projects, writing grants and working with the Wildlife Conservation Board and other non-governmental organizations on projects of shared interest.

We sometimes say that the Eastern Sierra is “the most beautiful part of California you’ve never seen.” What is unique about this ecosphere?

The Eastern Sierra is comprised of mostly public land with very little development compared to many other areas around California. This allows for intact wildlife populations to exist in vast expanses of native habitat. For example, the federally endangered Sierra Nevada bighorn sheep can be found in the high alpine environment in the summer months. They then move downslope in the winter to take advantage of available food not buried under snow. More than 600 bighorn in 13 occupied herd units can now be found in the Sierras, compared to 1995 when there were only 105 left after being devastated from diseases transmitted from competing domestic livestock in the high alpine meadows.

The sheer beauty of the tall mountains and the abundance of wildlife make it a truly special place. I enjoy hearing the tule elk bugling in the fall evenings near the Owens River. If you really want a treat, you can wake up before the sun rises to go observe the greater sage grouse congregate on their leks (meadows or barren areas with little cover) during the spring breeding season. The males put on quite a display in hopes of attracting a female by puffing out their chest, inflating air sacs and making unique sounds that I equate to drops of water.

What kinds of projects are conducted on the reserves and wildlife areas you manage?

Our activities are quite diverse, including managing water rights and grazing, controlling invasive species and performing various wildlife surveys. I serve as the lead for the Eastern Sierra bobcat study, which was initiated in 2014-2015 as part of a three-year project to assess current populations in Inyo and Mono counties. Specific data collected during the study include bobcat population size, density and age structure, as well as home range size, habitat selection, prey base and reproduction.

I also am also the lead for the low-elevation mesocarnivore survey project. This involves the use of remote cameras to capture detailed images of wildlife species such as bobcat, coyote and gray fox. The surveys help us estimate the percent of the study area that a species of interest occurs by placing one camera within a 10.4 Km cell and surveying 100 cells over multiple weeks. The data collected provides occupancy of the species surveyed. Capture-mark-recapture surveys can be done using this method with species such as bobcats that can be identified because of their unique coat patterns.

Inyo and Mono counties have been divided into eight study areas using geographical boundaries that the mesocarnivore surveys will be rotated through. Initially, these surveys will provide occupancy and abundance of individual species within each study area. Over time, data collected from the surveys can be useful to identify population trends.

What has been the most satisfying part of your CDFW career?

I really enjoy working with outstanding people who are focused on managing and conserving the state’s most important places and wildlife. I’m particularly proud of the conservation work that’s been conducted for the benefit of the Round Valley deer herd. We purchased several important properties within its winter range in Rovana and Swall Meadows, with the goal of protecting an intact migration corridor for them to move up and down in elevation to and from their winter and summer ranges.

What projects would you undertake if you had unlimited money and resources?

I am passionate about conserving natural areas for the perpetuation of healthy ecosystems and the wildlife populations they support. California is an incredibly biologically diverse state and these places are truly unique. By protecting them, we will allow them to be enjoyed generations to come. My most recent focus has been working to conserve the greater sage grouse through land acquisition and conservation easements. Funding all of the proposed actions in the Bi-State Action Plan for Greater sage grouse would be a dream come true.

CDFW photos.
Top photo: Alisa Ellsworth works a Sierra Nevada bighorn sheep capture.