Climate Change

Species Resilience and Science Advocacy: Getting to Know the Whitehead Lab at UC Davis

Dr. Andrew Whitehead working in the field
Dr. Andrew Whitehead in the field, deploying minnow traps to catch Gulf killifish, during our studies on the ecological impacts of the Deepwater Horizon oil spill. Photo Credit: Patrick Sullivan
Written by Nicole Drake

In the lab

Genetics, climate change, and conservation become highly intertwined in Dr. Andrew Whitehead’s lab. Although he works on a variety of research endeavors, he mainly focuses on how wild species respond to human-induced stress, such as the effects of climate change, and how that may affect an individual organism’s progeny. Essentially, Dr. Whitehead attempts to monitor how climate change and pollution will shape the genetic makeup of multiple generations.

“What we study are the consequences of how humans are changing the environment." He said "When we think of environmental change, we can think on a long timescale of mountains moving, but since humans became abundant in the last couple thousand years, that’s radically altered a lot of environments….So we need to look at how biodiversity is changing because of human-environmental change, and predict what kind of species are at highest risk.”

Killifish have been a key model species for Whitehead lab research. Killifish are well-adapted to live in estuaries, which are naturally stressful places. Estuaries comprise the area where a river meets the ocean, so they are filled with constantly shifting factors, strong water currents and human pollution. Therefore, killifish must be flexible to change in order to do well in their environment. Whitehead’s labs study what makes species resistant to change and how human-caused changes in environment might break the species or force them to adapt to additional human stressors like climate change. The data Whitehead’s lab analyzes allows them to begin building a model which can predict how dire each organism’s ecological situation is. From there, conservationists can prioritize the appropriate species which may be more closely threatened by environmental changes, and may allow more species to be retained to keep biodiversity at a steady level.

Atlantic killifish
Atlantic killifish (Fundulus heteroclitus). Image credit: Andrew Whitehead

Accomplishments and minor setbacks

Dr. Whitehead is proud of how his work combines different disciplines and blends fields together, allowing a melange of applied and theoretical science to uniquely study human impacts over short and long timeframes. He said, “I like that we really try to understand resilience over different time scales; we consider [our subjects] evolutionarily and physiologically. Something that’s become apparent is that in 20, 30 years of evolution, things unfold very quickly. We often think of evolution as a gradual process, but in some cases, species can also evolve very quickly to changing environments.” 

It is not necessarily all fun in the lab; being an environmental researcher with the Trump administration has come with its difficulties. Dr. Whitehead admitted that it may be difficult to handle the pushback researchers often receive in his field. Corporate money and lobbying against environmental legislation are difficult to fight against, in addition to the physical bombardments that can occur. He said,” We get pushback by petrochemical companies and their allies trying to discredit our research at conferences and meetings, particularly our students.” However, he retains hope that good will come out of these difficulties. “It’s an opportunity for a discussion. [The hecklers] don’t have the capacity to raise doubts about the science, so they just try to discredit the research. We just try to stick to the science and let it speak for itself,” Whitehead said.

The image of “an entirely objective scientist in a white lab coat” is something that Dr. Whitehead endeavors to push against. “It’s not good enough these days. Scientists need to be better advocates for science and truth, and try to communicate the take-home messages from their research,” he said. Whitehead believes that an issue of image lingers throughout society, with people perceiving scientists’ authority to be compromised once they start to advocate for their research instead of stay huddled in the lab. He said, “I’m coming around to the idea that we [as scientists] need to do more. Keeping on the lab coat has, in a lot of ways, failed.”

Despite these negativities, UC Davis makes the task of staying positive easier according to Dr. Whitehead. He said, “I appreciate the breadth and depth [of the research] that you find here; a lot of institutes just have one or the other. I’m surrounded by world-class researchers which is a huge benefit….To be surrounded by such talented folks is so great for me, and [Davis’s] geographical location is hard to beat.”

Classes with Dr. Whitehead

Whitehead’s classes at UCD are something he is also passionate about. He teaches EXT120 (Aquatic Toxicology) and EXT150 (Evolution in Human Altered Environments), each of which excite him to spread the knowledge that the courses contain. Dr. Whitehead described EXT120 as though “you take toxicology and put it underwater to see what’s important to chemicals [there].” His main interest is in EXT150, which expands the course’s view beyond toxicology and incorporates evolutionary biology, agricultural science, and urbanization of society, amongst other topics. According to Whitehead, “Toxicology itself is just a fraction of the course. It takes a much broader view beyond that, to include the many dimensions in which human activities alter the environment.” 

Beyond anything else, Dr. Whitehead urges students to reach out and get to know their professors.

He said, “There’s a preconceived notion that professors are unapproachable, but there’s nothing more they want to do than talk about their research. Most professors are willing to put aside an hour or so to talk to you about their research; I’d say nine out of ten times you’ll get a positive response.”

Dr. Whitehead encourages all students to attend lab meetings, volunteer, and reach out to their professors. He wants everyone to realize that “Sending an email a couple of times isn’t being annoying, it’s being persistent.” 

To contact Dr. Andrew Whitehead, email him

Meet the Author: Nicole Drake

Nicole Drake is a third-year UC Davis EEB major and ENT minor. She is also a trained and certified yoga instructor who enjoys walking on the beach and a good cup of coffee. Nicole previously worked at the San Francisco Zoo and has a great passion for wildlife conservation and ecology. Her favorite animal to work with was the Magellanic penguins




Mathematics and Kelp Collide in California’s Coastal Waters

Jorge Arroyo-Esquivel on the Bodega Marine Reserve
Jorge Arroyo-Esquivel on the Bodega Head State Marine Reserve

Written by: Jessica Ramos

California’s Kelp Forests

Dense canopies of kelp are a well-known and much-loved feature of California’s coastal waters. Kelp forests create subtidal havens for marine life like red and white abalone, urchins, sea stars, and rockfish. Once plentiful, kelp along the coast of California has faced multiple stressors, each exacerbating the devastating effects of the others. In 2013, many of the sea stars that once thrived in kelp forests fell victim to a mysterious wasting disease, leaving populations of urchins who were once consumed by voracious sea stars to feast on the abundant kelp without mitigating effects from predation. Warming waters have also contributed to the decline of kelp forests by stressing the delicate fronds and affecting their reproductive capabilities.

Mathematics and Kelp Collide

Jorge Arroyo-Esquivel, a 3rd year Ph.D. student at UC Davis, is studying ways to gauge and predict the long-term effectiveness of efforts to restore the vibrant kelp forests of California’s coastline. Arroyo-Esquivel is a member of the applied math graduate group under his advisor, Dr. Alan Hastings, and explains that much of their work explores population dynamics, a branch of mathematical biology. By examining the ways in which species interact with their environment, he is able to create theoretical models and predict future shifts in population. As Arroyo-Esquivel puts it, “We’re always trying to answer the question: if I have a group of individuals from a species, will they grow?”

Arroyo-Esquivel knew he wanted to be a marine biologist by the time he graduated from high school. However, life took a different turn once he started college, taking on both physics and biology courses concurrently. Finding that the workload of the two focuses was intensely demanding, he chose to carry on with physics, completing his undergraduate degree in mathematics in his homeland of Costa Rica before coming to California to pursue his Ph.D. at UC Davis. However, upon hearing about the plight of California’s kelp forests through his fiancé, also a Ph.D. student at UC Davis, Arroyo-Esquivel resolved to learn more about the situation and try to come up with a solution.

The first step towards making this a reality was taking a class with Dr. Marissa Baskett, a Professor in the Department of Environmental Science and Policy at UC Davis and Associate Director of Research Initiatives at the UC Davis Coastal and Marine Sciences Institute. In her research, Dr. Baskett uses mathematical models to explore the drivers of adaptation and resilience to environmental change in marine systems, and how management might affect that adaptability.

Purple Urchin
Photo by David Slipher

Evaluating Methods and Success

Under Dr. Baskett’s guidance, Arroyo-Esquivel is putting theoretical ecology to work in developing mathematical models that gauge the effectiveness of three key methods of kelp restoration proposed by NOAA:

  • Harvesting purple urchins in order to prevent their ever-growing populations from devouring the remaining and newly forming kelp.
  • Kelp planting by “seeding” areas with kelp spores in an effort to make it easier for new kelp plants to grow.
  • Kelp replanting, which involves growing kelp in a protected area and planting it out into target areas once it has reached maturity.

Each of the three methods offers promise, and Arroyo-Esquivel’s modeling seeks to determine not only which would be most successful, but also how the methods interact with each other and how cost-effective each is in terms of long-range success. Although the study is still in progress, they’ve already found that replanting partially grown kelp seems to have the highest success rate but is also the most cost-prohibitive of the three, and therefore the most difficult to implement on a large scale. Arroyo-Esquivel also noted that if urchin populations are brought below a critical level in restored areas, kelp forests are often able to maintain a healthy level of growth with little further intervention, making urchin harvesting a strong contender in restoration strategies.

“Even a single strategy can have a huge impact” Arroyo-Esquivel notes, and explains that ultimately, it comes down to balance. “Recovering more ground of the coastline just doesn’t seem to be possible when the urchin population exceeds the healthy baseline for an area, but when we increase the amount of kelp, the number of urchins that area can sustain and still remain healthy increases alongside it.”

Un-Kelpful Challenges

One of the challenges Arroyo-Esquivel and the rest of the project team has encountered is the difference in kelp species in Northern and Southern California. South of San Francisco, giant kelp (Macrocystis pyrifera) is the predominant species all the way south to Mexico, whereas north of San Francisco the dominant species is bull kelp (Nereocystis luetkeana). Because the two species differ in some important ways, measuring restoration progress requires some ingenuity. For example: from above, giant kelp looks more or less the same year-round because it is perennial and continues to grow year after year. In contrast, bull kelp is an annual, completing its life cycle in a single year, which makes it difficult to capture an accurate estimate of bull kelp populations via aerial photography. The often misty conditions off the shores of Northern California also exacerbate the difficulty of capturing accurate aerial information about kelp forests.

What’s in Store for California’s Kelp Forests?

Looking to the future, the team hopes to develop more detailed models and simulations to find an ideal balance of methods for restoration efforts, and Arroyo-Esquivel will be participating in a recently funded kelp recovery research project being conducted by researchers at the Bodega Marine Laboratory. He also hopes to see recovery efforts aided by the eventual reintroduction of sea stars, including Pycnopodia helianthoides, or sunflower sea stars, a familiar sight off the coast of California prior to the insidious advance of wasting disease. Recovery of this and other sea star species could add important balance by reintroducing predation to the purple urchin populations within kelp forests.

Although kelp restoration efforts still have a long way to go, Arroyo-Esquivel is excited to be able to apply his mathematical knowledge and training towards protecting coastal and ocean ecosystems, a subject he’s always felt passionate about. He hopes that the insights gained by this project will lead to even stronger implementation of recovery methods and a more resilient and hopeful future for California’s kelp forests.



Will Mussel Aquaculture Be Viable Along The California Coast?


By Priya Shukla

Mussels are found the world over. Many native freshwater mussels are admired for their ability to clean our streams and rivers, while invasive ones (which are actually clams masquerading as mussels!) are reviled for voraciously eating plankton and clogging pipes. The shells and tissues of mussels are often used as monitoring instruments because they reliably record changes in the surrounding environment.

musselsIn western North America, tightly packed conglomerations of the California mussel span from southwest Alaska to the end of Baja California. And, archaeological evidence indicates that the indigenous peoples of western North America consumed these mussels 13,000 years before moules-frites appeared on seafood restaurant menus in Pacific coast backwaters.

Although mussels have a rich tradition in European cuisine – going so far as to appear in Enlightenment-era art – oysters have reigned as the primary shellfish consumed throughout the United States, including in California. As demand for oysters grew and natural populations dwindled, the U.S. oyster industry transitioned from harvesting natural oyster beds to growing them in coastal waters (“aquaculture”). Oysters have been farmed in California since 1929, but mussels have been farmed in Europe since the 13th century. With global demands in seafood increasing, mussel farming – a $3 billion global industry – is now emerging along the California coast.

musselsAquaculture was responsible for nearly half of the seafood consumed in 2015, and farmed shellfish made up 10% of all seafood consumed that year. Mussels grow the most easily of all farmed shellfish, reaching market size within a year. They are incredibly nutritious; a single Blue Mussel contains only 290 calories, but has 40g of protein and 1,500mg of Omega-3 fatty acids. While these characteristics make mussels an ideal target for a profitable business and for securing food resources around the world, it is unclear how the changing climate will affect the success of these mussel farms.

California’s coastline is on the frontlines of climate change. San Diego saw its warmest ocean temperatures this past summer, a toxic algal bloom closed the San Francisco Bay Area Dungeness Crab industry in 2015, and oyster and abalone farms are actively combatting acidifying waters. Mussels, like oysters and abalone, build a protective calcium carbonate shell to protect their soft tissues from the elements. In more acidic waters, mussels – especially young ones – have a hard time building their shells and the protein-laden byssal threads (“beards”) that they use to secure themselves to the rocky shore degrade. They are also incredibly sensitive to rises in temperature.

beachFor my doctoral research at UC Davis, I plan to study how climate change will affect the mussel aquaculture industry. Because farmed mussels are often suspended on ropes using their byssal threads, I am interested in exploring whether warmer, more acidic waters will prevent mussels from staying attached to ropes and affect their overall production. Mussel aquaculture presents many opportunities in California and around the world, and I hope to use my research to make mussel farms an enduring and robust enterprise as the oceans continue to change.



Empathy as a Universal Language

By Ashley Collier Smart

In spite of the environmental disasters that are caused by mining and burning coal, I cannot help but be at least a little fond of it, if only for selfish reasons. For the last 300 years, coal work has provided a livelihood for my relatives—I have the family name of Collier to attest to this fact. During an age when people adopted their trade as a last name my relatives were employed as Colliers, or coal miners. I come from a line of Colliers dating back to the 1700’s with relatives working in coal in western Europe before immigrating to America.

My family’s story is the story of coal and the American Dream, where workers believed hard work could translate to economic freedom. Nearly one million people a year were involved in mining coal at the peak in the 1920’s. These jobs provided a stable source of income that did not require an extensive skill set for native-born and recently arrived immigrants. However, coal mining was a dangerous profession fraught with lax worker regulations and precarious mine construction. The lives of coal miners became collateral for keeping up with the increasing demand for heating fuel and electricity that drove the greatest advances in the quality of life ever known.

burning coal
Burning coal and the release of carbon dioxide is one of many ways coal disrupts the environment. Mountaintop removal is a method of coal extraction which negatively alters the surrounding ecosystem (Photo: Wikipedia).

As the scientific process chugged along and coal burning was discovered to be a potent contributor to climate change, coal gained a dirty reputation and rightfully became a target for regulations. A new generation, my generation, has grown up with increasing alarm at the prospect of irreversible climate change and the coal industry a political issue. It wasn’t only coal that was vilified, but it was also the people who mined coal. Simultaneously revered and disenfranchised, coal workers moved from providing the fuel for the engines of the American economy to being unemployed en mass in economically depressed regions as green energy alternatives became more popular.

As a climate scientist, I study the consequences of increased oceanic acidity which is a by-product of fossil fuel combustion, but because of my coal connections I recognize the complexity of the human element of coal. My association with coal is not simple, but nuanced, filled with both rational and emotional connections for and against coal–and I don’t think that this is an uncommon position. In an increasingly partisan environment where dog whistling defines the political norm, we risk creating false dichotomies that pit coal workers against the environment.

Coal burning contributes to climate change and must be reduced, but it has historically provided a reliable livelihood for many people in impoverished areas. We should be more cognizant of the regional impact of reducing coal mining and empathetic to facilitate productive conversation. We need to lie down our verbal weapons and listen. Of course, this doesn’t mean that we have to agree with the decisions people make, but an awareness of why people feel the way they do fosters trust and allows these conversations to take place to develop solutions.

Atmospheric levels of carbon dioxide
Atmospheric levels of carbon dioxide have rapidly risen since the industrial revolution. The NOAA Mauna Loa Observatory has tracked levels of carbon dioxide in the air starting in 1958.
coal workers
Coal workers traditionally engaged in dangerous mining work where they were exposed to a number of toxic substances (Photo: Wikipedia).
Av number of coal workers
Average number of coal workers in the United States from 1890 to 2015. The number of coal workers has declined over time resulting in displaced workers in economically depressed regions (Photo: Wikipedia).