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.

Dave Lancaster is an environmental scientist covering Humboldt and Del Norte counties for the Northern Region’s Wildlife Management Program. He has been a unit wildlife biologist for the past 13 years, covering a variety of issues involving birds and mammals including hunting program management, human-wildlife conflict, wildlife disease and welfare, habitat restoration, special-status species protection, population monitoring, research and providing technical assistance to other CDFW programs, agencies and the public.

Dave grew up in eastern Oregon and graduated from Oregon State University, earning Bachelor of Science degrees in both Wildlife Science and Fisheries Science. He has worked as a biologist for more than 20 years, the last 17 of which have been with CDFW.

What led you into a career as a wildlife biologist?

Hunting is a part of life out in rural eastern Oregon, and you start young. This early introduction to game quickly grew into a much wider appreciation for the land and wildlife in general. While there are a number of different jobs that allow a person to satisfy their desire to work out on the land, being a wildlife biologist provides an opportunity to work for the benefit of wildlife and the people who appreciate it.

It is interesting that you have degrees in both Wildlife Science and Fisheries Science. How did that come about?

I wanted to have a career in wildlife management, but most of the work was in fisheries, so I was hedging my bets.

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

Early in one’s career as a biologist, it is often necessary to be flexible and willing to go where job opportunities take you. Like many people in other states, my image of California was crowded freeways and urban sprawl. I never imagined I would make a career here, but when a job came up, I took it, figuring I would not be here long. It was a nice discovery for me that California still has a wealth of wildlife and wildlands, and diverse opportunity to work toward making a material contribution to conservation.

What is a typical day like for you at work?

Unit wildlife biologists have such a wide variety of duties that we typically work on several distinctly different issues in a day, and frequently have our plans changed by new developments occurring in any one of the many tasks we cover. I may on a given morning start to design a study, do a survey or prepare a management plan. Then the phone rings and I am being told a bear broke into a chicken coop, a deer is tangled up in barbed wire or a group of birds has been found dead on the beach – and the day just changed.

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

There are so many rewarding moments in a biologist’s career, it is difficult to pick out one particular thing. There are those projects that are not enjoyable to work on in the moment, but are very rewarding in the end because of the benefit to wildlife they produce. For example, developing habitat improvement projects and mitigation for impacts from development projects involve a lot of time at the desk, in meetings and conferring with folks with differing opinions and goals. Then there are the days when you are out in woods, grasslands or marshes doing surveys or tagging wildlife. You also get personal satisfaction and thanks from the public for helping a particular animal in some form of distress, such as when a deer or an elk is tangled up in barbed wire and you are able to free it up and send it on its way. On other days, you get the opportunity to help a person who is having some type of problem with wildlife. Of course, for wildlife biologists, any day improving the outlook for wildlife constitutes a good day, but if doing so happens to involve watching, handling or tracking animals, then all the better.

What is your favorite species to interact with or study?

The groups of species that I interact with most frequently are game birds and mammals, typically through managing hunting programs, helping landowners who are having conflicts with wildlife and responding to disease outbreaks. I do not have one particular favorite species. It is a diverse and fascinating world out there, with each one having its own appeal.

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

Figuring out how to restore and maintain native grassland habitats while accommodating commercial livestock ranching in the shrub steppe of the Great Basin and in coastal montane prairies would be high on the list in terms of landscape-scale conservation priorities. These areas provide important wildlife habitat but the livestock industry is important as well to these rural communities. Providing for both is the key to success in the big picture.

What is it about the work you do that you would most like us to know?

Unit wildlife biologists, as with staff from most of CDFW’s programs, work every day to find practical, effective solutions to complex problems, and try when doing so to satisfy a diverse range of constituents. We have to be practical because the decisions we make and the work we do often directly affects both our constituency and conservation actions carried out on the ground. We have to come up with solutions that actually work, not just in theory; they must work for wildlife, be compatible with landowners’ desired use of their property and be implemented in a cost effective manner. Take hunting as an example: you need to provide for the ecological integrity of the wildlife population being hunted and the habitats and other species that interact with it, and provide for use by the public both in the form of hunting and viewing opportunity, and use hunting as a tool to minimize property damage the hunted species may be causing on private property.

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

Get out in the field and read all the quality scientific literature you have time for. The university and on-the-job training are key components to building knowledge and competency, but a lifelong habit of self-education is indispensable. A broad familiarity with the collective knowledge compiled by those that came before us, tempered with extensive and considered first-hand observations from the field, are what make a good biologist.

Krysta Rogers is a senior environmental scientist at CDFW’s Wildlife Investigations Laboratory. She is the statewide lead for avian mortality investigations. Her professional experience has been focused almost exclusively on birds, including bird identification, biology, ecology and behavior. She has led and participated in numerous field projects including bird surveys, trapping, banding and sample collection.

Krysta earned both her Bachelors and Masters of Science degrees in Wildlife from Humboldt State University. She came to CDFW in 2007 as a wildlife biologist, starting out as the avian influenza surveillance coordinator. She subsequently worked on developing the lab’s Avian Investigations program, which includes mortality investigations, disease research and health surveillance for the many different bird species in California.

Who or what inspired you to become a scientist?

I had an interest in animals from a very young age and pursued this initially in the field of veterinary medicine. Although I enjoyed the animal health aspect, I learned I did not want to become a veterinarian in a small animal practice. I was unaware of other career possibilities until I took an elective course on endangered species at my local community college. The class introduced me to the career of wildlife biologist which subsequently informed my decision to attend Humboldt State University to obtain a degree in Wildlife. Later, while working toward my Master’s degree, my thesis advisor, Dr. Rick Botzler, taught me how to incorporate my interest in animal health into the study of wildlife biology.

What is a typical day like for you at work?

As the lead for avian mortality investigations, I spend most of my time responding to reports of dead birds from CDFW staff, other agencies, wildlife rehabilitation centers and the public. Given that most birds are active during the day and are thus highly visible to the public, these reports come in almost constantly. For investigations, I obtain carcasses for post-mortem exam to determine the cause of death, which may inform management actions. I either will perform the gross necropsy myself and submit various tissues for testing, or I will coordinate with another lab for the post-mortem exam and testing. Then I interpret the results and determine the next course of action. These investigations are varied – for instance, house finches and mourning doves dying from diseases at backyard bird feeders, juvenile California scrub jays and Cooper’s hawks dying of West Nile virus, Western and Clark’s grebes dying from starvation along the coast and at inland reservoirs, or bald and golden eagles dying of toxicosis or electrocution.

What is your favorite species to interact with or study?

It’s impossible to pick a single species; I’m interested in birds in general. There are more than 600 species of birds in California that live in a diversity of habitats. Different diseases or conditions can affect different species. This great diversity means always having the opportunity to learn something new in terms of species biology, a pathogen or environmental impacts.

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

Investigating causes of mortality is almost like being a detective. You need to gather lots of detail and determine what factors are relevant to the cause of death for a particular animal. Sometimes this may be relatively easy with a pathogen or condition you routinely investigate, but sometimes it’s something entirely new. This aspect keeps the investigations interesting.

What is the most challenging part of your job?

One challenge is communicating the importance of incorporating animal health into resource management and conservation plans. For many avian species, we don’t have even a basic understanding of the impacts of diseases or contaminants that may influence population growth or decline. The lack of this information may limit our ability to manage species over the long-term, especially in the face of climate change. Climate change will almost certainly favor certain pathogens or host species that can aid in disease transmission.

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

So far, it’s been collaborating with researchers at the University of California, Davis to investigate avian trichomonosis in our native band-tailed pigeons. Avian trichomonosis is a disease caused by a protozoan parasite that in band-tailed pigeons causes near annual large-scale mortality events. This project enabled us to genetically characterize the parasites infecting band-tailed pigeons, including naming a new species of parasite, and evaluate the ecological drivers and the population impacts of these disease events on band-tailed pigeons, a migratory game species.

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

I’d like to work towards an improved understanding of the impacts certain pathogens have on different avian species. This would include genetically characterizing the pathogens, identifying host range, and learning how avian species interact with their environment and the means by which they are exposed to certain pathogens.

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

Because there are so many career options in the field of science and natural resources, I’d recommend trying to get exposed to a diversity of people and projects as early as possible (e.g. junior high, high school). This can be accomplished through interviewing professionals, volunteering, internships and paid jobs. Learning about the different career options enables you to determine your interests and will help guide your educational path and eventually your career goals.