Featured Scientist

Christy prepares for a day’s work underwater at La Jolla.


Christy Juhasz works on an abalone density survey off the northern California coast.

CDFW Environmental Scientist Christy Juhasz works for the Marine Region’s Invertebrate Management Project, where she is primarily responsible for managing California’s Dungeness crab fisheries. Christy coordinates preseason quality and domoic acid testing for the commercial fishery, summarizes seasonal landings data and works on rulemaking proposals for both the commercial and recreational Dungeness fisheries.

A Southern California native, Christy earned a bachelor’s degree in marine biology, with a minor in oceanography, from the University of California, Los Angeles. Soon after graduating, Christy’s first paid position involved monitoring and trapping the invasive European green crab in several northern California bays and estuaries. Afterwards, she began working for CDFW as a scientific aid at the Shellfish Health Laboratory, located at the Bodega Marine Laboratory in Bodega Bay, where she spent several years testing quality control measures of a sabellid, polychaete worm that had been introduced at aquaculture facilities.

In 2007, she became a certified CDFW diver and began assisting in abalone density surveys conducted on the Sonoma and Mendocino coasts. In 2011, she was hired in her current position to work on Dungeness crab fisheries management.

What led you to a career in marine biology?

As a child, I spent an inordinate amount at the coast and particularly enjoyed exploring tidepools. I was always fascinated by the creatures that eke out an existence on the water’s edge, fostering my love of marine invertebrate species. This only grew after taking an invertebrate taxonomy course, becoming certified in scientific diving and volunteering at a small, local marine aquarium while in college where I was able to share my love of native California marine life with the public.

Not many people can say they get to dive as part of their job duties. What’s that like?

Before coming to work at CDFW, most of my diving experience was in the warmer waters of Southern California and the Bahamas for training and research, respectively. Diving in the colder and rougher northern California ocean waters has been interesting. My job has taken me to some beautiful underwater habitat where diverse and colorful kelps, invertebrates and rockfish species abound, while also making me a much better diver.

One interesting CDFW dive location includes the site of Mavericks, although not at the height of the surfing season. We were there to assess the red abalone population within the Marine Protected Area and I was able to observe firsthand the effects of the intense wave action that had eroded away the subtidal rocky reef promontories.

How frequently do you get to dive?

Recently, I had my first child so have not been able to get back underwater as intensely since before I was pregnant. Prior to this, I was an active CDFW diver, primarily assisting with monitoring red abalone populations in the summer months. Diving and field work, in general, are always fun to go out and do in coastal locations, but they do require a lot of planning and preparation. Actual collection of data while SCUBA diving really teaches you to be in the moment, as you have multiple tasks to complete underwater. Obviously safety is paramount and you have to pay attention to the air you consume while you’re working, which ultimately limits the amount time you have underwater.

Today, most of your work relates to Dungeness crab. What do you find interesting about this particular fishery?

The Dungeness crab commercial fishery is one of California’s highest valued fisheries and is also one of the state’s oldest fisheries. In fact, regulations governing take of legal-sized males around a set seasonal period date back to the turn of the 20th century, and are known as the 3-S management principle (sex, size and season). The fishery does widely fluctuate from season to season, but with California landings dating back to just over 100 seasons, there have been no observable, long-term crashes in catch history. In recent seasons, the fishery has experienced some record landings in both management areas of the fishery, especially in the central region, which in the past decades rarely contributed to the majority of statewide landings.

I enjoy and thrive in my job under the dynamic and varying responsibilities and tasks that support the operations of the fishery. Whether I’m working on rulemaking packages, meeting with constituents for various issues or incorporating new or more extensive sampling procedures – it’s all very interesting.

Do you work with species other than Dungeness crab?

Yes. Some of my monitoring and rulemaking work involves other invertebrate fisheries in California, which have been increasing in importance (see link to journal article below). This raises new challenges for fisheries managers, especially considering the many invertebrate fisheries we oversee and the various life history strategies characteristic of each species.

For instance, red urchin and red abalone have to be relatively near one another for successful fertilization after they release their gametes into the water column. This is in contrast to Dungeness crab, which mate during the period when females molt, and brood eggs before they hatch. These differences just reveal how each fishery requires a unique set of regulations to effectively manage them.

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

I have been collaborating with other CDFW staff to monitor the arrival of the Dungeness crab megalopae – that’s the last pelagic, larval stage of crabs before they molt and settle to the bottom as juveniles – to California’s bays and estuaries. The study aims to determine if there is link between their relative number and size, and perhaps predict commercial catch three to four years later, which is about when these crabs would grow into the fishery. Work on this is still preliminary, but in the time we have been observing, we have noticed big differences in total numbers and average size. This may be driven by optimal ocean conditions since the planktonic larval stages spend an average of four months total in the water column during the winter and spring months.

I’m also involved in the rulemaking process for the Dungeness crab commercial fishery. One current development is the creation of a formal statewide program for incentivizing the retrieval of lost and abandoned Dungeness crab traps at the end of each season. The fishery has rules in place such as the use of a destruct device that wears away, to allow escapement and prevent a lost or abandoned trap from continuously capturing organisms. However, traps attached to a buoy with vertical lines in the water column that remain in the water past the season pose additional hazards to marine life and vessel traffic. The industry has been piloting local programs for the past several seasons. A formal program is expected to be in place by the end of the 2018-19 season.

Recent seasons of the Dungeness crab fishery have been plagued by high domoic acid levels and low quality, leading to season delays. How has this changed the nature of your work?

The pre-season quality testing has been conducted for the northern portion of the fishery for many years in concert with Washington and Oregon testing. Although procedures have been modified over the years, the scheduled delays are built into the current operations of the fishery. The fishery cannot be delayed due to quality issues past January 15, whereas with domoic acid season delays are unpredictable.

Our efforts to monitor Dungeness crab are more extensive before the start of the season. Dungeness crab fishermen are key players in this task, as I call and email with them to collect and retrieve samples throughout the fishery’s range statewide (this is similar to how the quality testing is conducted as well). I also coordinate with staff from the California of Department of Public Health to ensure that samples collected are properly received by their laboratory testing facility. During the 2015-16 delayed season, CDFW staff worked tirelessly on this sampling effort while navigating the problem under current regulations and effectively communicating the latest information on the status of the delay and potential opening of the season. This was especially important in light of lost revenue due to the unforeseen delays.

Do you expect that domoic acid will continue to be a problem in future seasons?

Domoic acid is a neurotoxin produced by a unicellular algal organisms that thrive in warm water. The domoic acid problem that caused the severe delay of the 2015-16 season was thought to be a direct effect of the anomalous (unusual) ocean warming from the “warm blob” that developed off of US West Coast in 2014. As these anomalous warming ocean conditions persist, so does the problem of harmful algal blooms that cause domoic acid. This has become a top priority for discussion between industry, the Dungeness crab task force and other affected fisheries and agencies. 

CDFW Photos. Top Photo: Christy measuring a dungeness crab.

For Further Reading:

• 2011 Annual Status of the Fisheries Report – Dungeness crab (PDF)
• Marine Invertebrate Survey and Assessment Project
• The Rise of Invertebrate Fisheries and the Fishing Down of Marine Food Webs in California published in California Fish and Game’s Journal 100th Edition (PDF)

Robert conducts a topographical survey of pool habitat on Big Sur River.


Robert and crew snorkel-survey Coho salmon and steelhead habitat use on South Fork Eel River tributary.

Robert Holmes is an Environmental Program Manager supervisor over the Statewide Water Planning Program in CDFW’s Water Branch. Robert leads efforts in the statewide implementation of the Instream Flow Program, sustainable groundwater management, and water rights activities.

Robert has been with the Water Branch for 10 years, and has worked on instream flow, water quality, and aquatic species and habitat assessments for over 20 years for the State of California. Robert is a freshwater biologist and received a Bachelor of Science from CSU Sacramento in Conservation Biology, and a Master of Science from Humboldt State in Natural Resources where his thesis work was on steelhead trout early life history development.

What inspired you to become a scientist?

I spent my childhood playing outdoors and learned a great appreciation for nature early on – exploring catching and identifying frogs, spiders, turtles, snakes and other critters. Basically, science has always been that pathway of learning about the outdoor world for me. I had lots of questions. What kind of spider is that? What kind of bird? What does it eat? Why is it only here in winter? Fast-forward to today and I’m still asking questions about the natural world, when I’m chasing fish to document habitat use and availability, collecting streamflow to determine gains and losses in a stream reach, or evaluating physical habitat suitability data. There are many rivers and places to explore, many questions to answer about the natural world, and much to learn!

What got you interested in working with water - and fish and wildlife?

Recreation! Growing up near the lower American River, I spent a lot time there with friends, riding bikes, swimming, skim boarding and fishing. In high school we would go snowboarding near Castle Peak, and later, whitewater kayaking and wakeboarding local rivers. On several occasions, when spring conditions were right, we would follow the westward flow of water from the summit to valley by hiking and snowboarding the backcountry of Donner Summit, kayaking a class IV stretch of one of the forks of American River, and then wakeboarding the lower Sacramento River. And that’s all in one weekend! I also like to fly fish. There’s nothing like those cold crisp winter mornings when fishing and it’s so cold your line freezes to the rod and you can barely feel your fingers. It’s worth it when you get the tug on your line, or a steelhead does a tail dance across the top of the water after taking your fly, and you pull them in and see that color! Drifting the Feather River or Yuba River for steelhead is fun, but trout fishing the Eastern Sierra is my favorite.

What brought you to CDFW? What inspires you to stay?

I was awarded a grant in graduate school at Humboldt State funded by the CDFW to develop a spawning and stocking program for coastal cutthroat trout in Humboldt County. At the time, I was also the assistant manager of the HSU Fish Hatchery. I formally came to the CDFW Water Branch in 2008 as the Statewide Instream Flow Coordinator. What inspires me and keeps me here is knowing how important the work is we do in developing instream flow criteria and recommendations for the protection and conservation of our fish and wildlife and their habitats. Our work is a critically important piece of information used by decision makers when balancing water needs and demands and determining water allocation schedules. We also have an awesome professional team who shares a solid work ethic, commitment, and passion for their work and meeting the CDFW mission!

What is a typical day like for you at work?

There is no typical day – really! Every instream flow study we work on and every associated river we step our boots in the water is different and presents its own unique challenges. One thing is for sure – there always needs to be a Plan A, and Plan B, and even a Plan C. Doing field studies brings lots of challenges. We have to plan our activities around storm events, rising and receding flow levels, droughts, access agreements, travel times, species periodicities, equipment limitations and so on. At the end of the day, the priority is always crew safety. We have had to call off several scheduled field days due to potentially unsafe conditions for our field crews presented by heavy storms and high streamflows.

What is special about working in instream flow?

Effective riverine resource stewardship and management is generally achieved by integrating science, policy and public involvement. We conduct instream flow studies to determine instream flow needs for fish and wildlife protection. These studies must be technically defensible, consistent with policies and coordinated and vetted in a transparent process. Therefore, success at achieving flow levels for the protection of fish and wildlife and their habitats is heavily reliant on this three-way interaction between the science, policy and public involvement.

What is special about the field of instream flow is that it takes a diverse, technically trained crew to do our job. For example, we have to draw upon all our scientific disciplines to get the job done – biologists, ecologists, hydrologists, water management scientists, engineering geologists, hydraulic engineers and others. I also get the privilege of working on external projects with some of the best and most well respected scientists in the field of instream flows, aquatic ecology and fisheries. Currently we are participating in an effort with hydrologists from UC Davis and other scientists to develop a statewide framework for assessing ecosystem and environmental flow criteria. This effort is really exciting as it has the potential to be very useful for several of our CDFW headquarters and regional program functions that use instream flow criteria for doing their jobs.

What is most challenging aspect of your job?

A commonly heard complaint of instream flow is that it is an issue of “water for fish versus people” and that instream flow practitioners advocate natural conditions in rivers at the expense of other water users. This idea is popular, but misleading, because all water uses – for recreation, for municipal supply, for industry, for fish and wildlife – are ultimately for the benefit and enjoyment of people in one way or another. In the long run, reserving water for instream flow is about the use and enjoyment of the river’s natural resources by future generations. Since these future users of water are not available to express their needs or desires, fish are often used as an indicator of healthy river conditions. So preserving instream flows (and fish) today actually preserves water management options for future generations.

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

Every project is rewarding in different ways. Probably most rewarding from a big picture view is knowing how important the work we do is in the decision making and balancing processes by the State Water Board. It was actually very rewarding to publish a recent study of steelhead habitat selection and availability from the Big Sur River, which was initially approved for publication in North American Journal of Fisheries Management, in our very own Fish and Game Journal’s 100th year “Special Fisheries Issue” (PDF). There was only one chance to publish in this special issue – the next one is another century away! Our team has published multiple papers in several of the top scientific international peer review journals – but being a part of the 100th year of publication special fisheries issue was cool!

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

Understanding the relationship between surface water and groundwater on streams and rivers is really important as it has the potential to affect both the quantity and quality fish and wildlife habitats. Generally speaking, surface water and groundwater systems are connected in most landscapes and streams interact with groundwater in three basic ways: streams gain water from inflow of groundwater through the streambed, streams lose water by outflow through the streambed, or they do both depending upon the location along the stream. Groundwater seepage is vitally important to the hydrologic cycles and for fish and wildlife in California because it is responsible for keeping water in rivers during times of no rainfall (i.e., base flow conditions). I would really like to see more research into understanding these surface water and groundwater relationships on a regional and statewide scale and how this interaction can affect the base flows for fish and wildlife.

What is the best thing about being a fish and wildlife scientist?

The best thing about being a scientist is turning field data into information for decision making processes. Putting on a cold (and still wet) wetsuit in the morning and hopping into ice cold frigid water to survey salmonid habitat use would not be considered fun by many. But the best part is actually being in the water with the fish and observing and recording their behavior in their habitat – specifically observing the microhabitats they select to occupy (or not) and feed or hold, and how they interact among themselves and with other species as they grow and compete for resources – and as flow levels change. After collecting data it is the scientists’ responsibility of turning that observation data into information that natural resource managers, the public, and decision makers can use. Honestly, seeing this whole scientific process through – identifying study questions, study design and planning, implementation and then reporting – is the best part of being a fish and wildlife scientist!

Do you have any advice for people considering careers in science or natural resources?

Get your feet wet! Do internships while in college and try different jobs in the field of your interest. First, you will be able to figure out what is right for you, and maybe what is not. Second, these jobs, whether volunteer or paid, and the associated people you meet and interact with early in your education and career will likely be important as you develop professional relationships and move into a career down the road. And most of all – have fun! Science is important, challenging, rewarding and fun.

CDFW photos. Top photo: Robert conducting snorkel survey of steelhead habitat use on Big Sur River.

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.