Featured Scientist

Environmental Scientist Tom Greiner at the helm of CDFW research vessel Triakis.


CDFW Research Vessel Triakis on San Francisco Bay


Greiner holds a young leopard shark


Greiner on Humboldt Bay


Tom Greiner… just for the halibut

Thomas Greiner is an environmental scientist for the Aquaculture and Bays Management Project in CDFW’s Marine Region. He has more than 23 years experience with the department. Based out of the Santa Rosa office, his main duties include monitoring and management of the commercial herring fishery in San Francisco Bay and biological assessment of California’s estuaries.

Tom earned a double major in general Biology and Fine Arts from Eastern Michigan University. He came to CDFW in 1989 as a scientific aid. Afterwards he pursued a Master’s degree at Humboldt State University. After another stint as a scientific aide, Tom was hired as a Senior Laboratory Assistant for the CDFW’s San Francisco Bay Study and later promoted to Marine Biologist and Associate Biologist and is now an Environmental Scientist.

Who or what inspired you to become a scientist?

I have had an interest in nature, and animals in particular, since I was knee-high to a porcupine. My mother’s willingness to put up with all sorts of critters in the house certainly paved the way. Along the way several people tried to warn me that there are very few jobs in natural resources, but my stubbornness won out.

Can you give us an overview of the herring fishery and tell us why it’s important?

The primary commercial herring fishery in California occurs in San Francisco Bay. It is primarily a roe fishery with its product exported to Japan, where it is considered a delicacy and is a traditional holiday gift. There is also a smaller herring-eggs-on-kelp fishery and a fresh fish fishery for local consumption. In addition, there is a sport fishery for bait and food.

The San Francisco Bay herring fishery was once highly profitable, but a reduction in the price per ton paid to commercial fishers, due to competition from other fishing areas and diminishing demand in Japan, has led to reduced fishing effort.

What is a typical day like for you at work?

A typical day is spent in the office manipulating data and writing or editing documents, but work still takes me out into the field. In the summer, I occasionally help with fish rescues or sample the local estuaries by kayak using beach seines. Winter is my busy field season. I sample Pacific herring in San Francisco Bay aboard a research vessel by deploying a mid-water trawl. On a trawl day I typically get up long before sunrise and meet the crew, which consists of one boat operator (me or one of the other Herring Team biologists) and two winch operators. Once on the water, we look for cormorants, gulls, seals and sea lions to help us find schools of fish. After we have found a school, the vessel operator plans a strategy for the trawl which includes assessing potential hazards, determining tow direction (we tow with the current), and amount of line we need to let out to get the net down to the school of fish. We avoid trawling in rough seas or swift currents, but things can still get dicey – between vessel breakdowns, tangling up or ripping the net, and getting the net stuck in the substrate, trawling is often an adventure.

We collect data on age, length, weight and reproductive status from these samples. We use this data to assess condition of the San Francisco Bay Pacific herring spawning population. This information, along with a spawning biomass estimate made by another Herring Team member, is used to set the next season’s commercial fishing quota.

Managing the quota requires up to the hour information on herring fishing activity and landings along with coordinated, decisive action when calling for closure of the fishery to prevent over-exploitation of the herring resource. I coordinate fishery closures with the Herring Team, CDFW enforcement and the U.S. Coast Guard.

What is it about the work you do that you find most interesting or rewarding?

It is very rewarding working as part of a well-oiled (okay, occasionally squeaky) team to protect our natural resources. Precision teamwork is required both in the management of the commercial fishery and safely operating our sampling vessel.

What is the accomplishment you’re most proud of?

There isn’t one single accomplishment that I pride myself on above others, but instead it is my dependable, consistent, quality work. Through many years of study, I have developed a good reputation for reliable identification of estuarine fish and macroinvertebrate species. Continuous identification practice is important as I recently had a SNAFU concerning juvenile jacksmelt and topsmelt IDs – juvenile fish identification can be very tricky and the characteristics used to differentiate species in adult fish don’t always apply to the little guys.

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

Restoring and protecting habitat and native wildlife and monitoring the recovery would be very rewarding. Healthy and varied habitat is often the key component in an ecosystem. One nice part is that this can be done on a small scale and some benefits may still be observed. Planting one tree can make a difference, especially in an urban area that lacks trees.

Are you a recreational angler (or hunter) yourself?

It has been quite a while, but I occasionally fish for food. I think that my main purpose in fishing is to make my friends feel good because they catch more fish than I do. It’s been much longer since I’ve hunted, but I also support the idea of hunting for food.

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

Get a degree in biological sciences, natural resources or related field. Meeting working biologists is very helpful and volunteering shows motivation. Be flexible in the job locations and positions that you are willing to accept. Very few people get permanent positions with CDFW right out of college. You need to have persistence, persistence, persistence, grit and patience. And learn to be frugal – you won’t make a lot of dough in this profession.

Top Photo: Tom Greiner, Arn Aarreberg and Ryan Watanabe identify and measure fish and invertebrates sampled by beach seine from Estero de San Antonio, a coastal lagoon in northern Marin County.

Anna Burkholder is a senior environmental scientist with the Preparedness Branch of CDFW’s Office of Spill Prevention and Response (OSPR) in Sacramento. She is the statewide Inland Geographic Response Plan Coordinator, working with fellow OSPR staff throughout the state to develop inland response plans for waterways at high risk for an oil spill. She has worked for CDFW for 20 years, most recently joining OSPR in 2016. In addition to her role as response plan coordinator, she is training for two oil spill emergency response positions: wildlife branch director (the position that oversees wildlife response efforts during a spill) and liaison officer (which works to address stakeholders’ concerns during a spill).

Anna earned her Bachelor of Science degree in biology, with an emphasis in zoology, from San Francisco State University. She prefers being outdoors, hiking with her dogs, snowshoeing, paddle boarding and horseback riding. She volunteers with the DOVES Guidance Program, a therapeutic horseback riding program for at-risk kids, as well as for NorCal German Shorthaired Pointer Rescue. She is improving her skills at upland bird hunting, including pheasant and turkey, and is still waiting to take a shot at her first tom.

Who or what inspired you to become a scientist?

When the movie Jaws came out, I was both terrified and fascinated. To this day, it is my favorite movie and I am more thrilled than ever with sharks. I briefly met Peter Benchley, the author of Jaws, several years back at the Monterey Bay Aquarium and that was exciting. He was promoting a new book trying to dispel the terrifying image of Great Whites, which he felt partially responsible for creating. I was also inspired by Dr. John McCosker, a Great White Shark expert that works for the California Academy of Sciences in San Francisco. McCosker had begun investigating why shark attacks occur, assessing their danger to humans in the grand scheme of things. He has worked to help understand the importance of sharks in the ecosystem and how they relate to the health of our oceans.

What got you interested in working with wildlife?

Clearly I would have loved to study sharks but didn’t follow that path. Along the way though, some of my classes at San Francisco State got me interested in some aspects of wildlife. Studying the behavior of snow leopards at the San Francisco Zoo (they sleep a lot!) for my Animal Behavior class, and doing some mark and recapture studies of mice and voles in Pacifica for an Ecology class, were fun experiences.

Who or what brought you to CDFW? What inspires you to stay?

Pure luck brought me to CDFW. After I graduated from college, I was working for a biotech company in Hercules and wasn’t terribly happy with the work. I used to go for walks during my break time and look out over San Pablo Bay and think to myself, “I need a job out there.” While taking an oceanography class at night at a junior college, I was looking at the job board one evening and saw a posting for a temporary scientific aid position with CDFW, working on the Bay Study Project. I got the job and lo and behold, there I was out on a boat every month, sampling fish throughout the Delta and San Francisco Bay (including San Pablo Bay!). I have never looked back.

Twenty years later, I guess it was a good move for me. I stay because I love this department, mostly the people I work with, and the dedication and passion we all have for the environment and the strong desire to protect the species and habitats in the state.

What is a typical day like for you at work?

When I am not traveling to participate in oil spill drills, oil spill workshops or Incident Command System training, I spend time working on the Geographic Response Plan template document that will be used to produce regional plans throughout the state for oil spill response. I coordinate with my OSPR colleagues, as well as other state and federal agencies, oil spill response organizations and industry folks on the development of these documents so they can provide a useful tool in responding to an incident. It’s been great to meet and work with an entirely new set of folks that I haven’t come across in my career until now, and to have a common goal of preparing for oil spills and working to protect the public, the environment and economic resources in our state.

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

I’ve spent a lot of time in the field working on boats. I worked on the 2007 Pike Eradication project at Lake Davis, and even got to spend a day escorting Delta and Dawn, the wayward humpback whale cow and calf that swam up the deep water channel to the Port of Sacramento in 2007. We escorted them on the last day they were observed inside the Golden Gate as they made their way through San Pablo Bay and finally back out to the Pacific Ocean.

I would have to say the most rewarding project is shaping up to be my new job with OSPR. The office was established 25 years ago and has a very comprehensive marine program in terms of preparedness and response to oil spills, but since OSPR’s jurisdiction expanded to include inland in 2015, I get to be on the forefront of establishing preparedness plans to protect all waters of the state.

What do you enjoy most about your job?

I work with an amazing group of folks in every part of our department, and we have a common goal of preserving and enhancing the natural environment. Being able to feel proud of the department you work for and cheering on the achievements of others in your field is a great feeling. Not to mention some of the great days in the field, which include flying along the California coast to record data on nesting seabirds, looking for nesting grebes in high mountain lakes and touring the state’s bird and marine mammal rescue and rehabilitation facilities.

Is there a preconception about scientists you would like to dispel?

The term “environmental scientist” encompasses a wide range of job duties within the State of California, including field biologists and environmental planning and permitting staff. We certainly have state scientists who conduct important laboratory research, including folks who work for OSPR and conduct water analysis and DNA fingerprinting on oil products. And what’s wrong with a periodic table? I loved general chemistry class!

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

If it is what you love to do, then don’t shy away from following that path. You can try different aspects of working in the natural resources field and then focus on what you enjoy the most. I would volunteer or take shorter-term assignments to work with multiple organizations and get experience in different areas. Meet experts in their field and get a foot in the door through internships or part-time jobs. There are so many exciting directions you can go in this field.

In 2013, Stuart Itoga became CDFW’s deer program coordinator, which means he is responsible for understanding, managing and conserving California’s deer populations. An avid outdoorsman, Stuart was born in Chicago and raised in San Jose. He holds a degree in Wildlife Management from Humboldt State University.

Stuart first joined the department in 1995 as a scientific aide at the Butte Valley Wildlife Area in Siskiyou County after holding fisheries and wildlife positions with the U.S. Forest Service. He is now a senior environmental scientist.

California is home to both mule and black-tailed deer, both resident and migratory herds that wander more than 70 percent of the state and number about 500,000 animals. At the dawn of the state’s 2017 deer hunting season (the general season opens Sept. 16 in many parts of the state), Stuart shared some personal background and his professional outlook on the state of deer management and deer hunting in California.

Who or what inspired your love of natural resources?

I always liked being outside, but hunting and fishing with friends really did it for me.

What do you like best about your job?

I get to work with so many great people. I work with scientists from other state agencies, and it’s enlightening to discuss different conservation approaches with other agency staff. But working on deer projects with our scientists is the best part. They really care about conserving deer and our other natural resources. It hasn’t all been good, but working together, we’ve been able to do some really good things over the past few years. I like the direction we’re headed.

Are you a deer hunter yourself?

I am – or I used to be, at least. When I started this job as the deer program coordinator, I thought it might help me figure out where the best spots were, but this job keeps me so busy I just haven’t made the time to get out deer hunting the past few years. It doesn’t look like I’ll get out there this season either.

Hunters often remark that California’s deer seasons start too early, and that overall hunter success would be much better if the seasons started later in the year, closer to the rut as is the case in many other states. What do you think?

We could start seasons later, which likely would result in greater levels of harvest that couldn’t be sustained over the long term. This would mean fewer tags for hunters. Having some early seasons allows us to provide tags to a greater number of hunters. Our hunter survey overwhelmingly indicated that hunters prized just the opportunity to get out and hunt deer. So we try to provide a balance of opportunity and high-quality hunts. You may not get the hunt you really want in a given year, but you will be able to get a tag to hunt somewhere.

There are very limited doe hunting opportunities in California compared to other states. Wouldn’t providing more doe hunts not only improve hunter success but also help improve the overall health of California’s herds by removing some older does no longer able to reproduce?

Doe hunts are typically conducted to reduce deer density and negative impacts to the herd and the habitat that result from too many deer. We are currently updating our baseline population data with new methods that allow us to estimate deer populations with a greater level of precision and accuracy. We are assessing where we might be seeing high-density impact at work. There are some areas where the densities are around 12 deer per square kilometer and others about four. The question we’re looking at now is how many deer are sustainable over the long term and what the appropriate levels of harvest – male and female – need to be.

Going back to our survey, 85 percent of hunters supported a doe hunt if data indicated it was warranted. However, having the supporting data and the support of hunters is only part of the equation. In California and other Western states, doe hunts are not widely supported by the non-hunting public, and 37 of California’s 58 counties can veto the department’s recommendations for antlerless hunts.

Mountain lions are another sore subject for many deer hunters. They often get blamed for suppressing California’s deer numbers. To what degree are mountain lions impacting California’s deer herds?

Mountain lions are deer predators as are bear, coyotes, bobcats and people. We’re updating our baseline deer population numbers, which will help us determine the level of significance associated with lion and other predation. Without a good starting number, it’s impossible to tell what impact lions – or other predators – are having on deer populations. In addition to our population study with deer, the department is assessing the mountain lion population, which will also provide valuable information on deer-lion interactions.

I personally think the number of people in the state may be the biggest stressor on deer populations. A population of almost 40 million people has quite an impact on the state’s natural resources.

What’s one message you’d like to share with deer hunters as they prepare to head out this season?

One thing I hear with some consistency is, “There are no bucks.” Our trail cameras and fecal DNA studies, however, are showing us there are.

We conducted a hunter survey a couple of years ago as part of an update of our California Deer Conservation and Management Plan. That survey, combined with the level of effort information we get from the harvest reports submitted by hunters, tell us the average California deer hunter spends about eight days in the field. That’s a good deal of time and effort. So I’m not saying it’s easy to get a buck, but hunters that are consistently successful put some effort into their hunt and also spend time scouting beforehand. If you can get out before your trip and pattern the deer, you’re going to increase your chances of being successful.

Good luck to all of our deer hunters this year! If you’re successful, send me a photo at stuart.itoga@wildlife.ca.gov. (Don’t forget to tag it first!)