SUNSCREEN SHOWDOWN: OXYBENZONE AND HOMOSALATE AND ZINC OXIDE… OH MY!

Noah Kolander, Ichthyology Lab

Throughout most of recorded human history, we have not cared about the use of sunscreen. Or have we? It is now well known that the sun's rays can cause burns to the skin when left unprotected, but we have been trying to prevent such things for thousands of years. Initially, it was not to prevent cancer or getting sun spots but rather as a way to keep cool, prevent uncomfortable skin irritations, and, in some cases, prevent from looking like the lower class (Urbach 2001). Though trials were conducted in 1820, it wasn’t until 1900 that the same experiment was conducted where sunlight was split into “chemical rays” and heat. It was then that we realized that it was not just the heat that caused the burns but something different. This led to the invention of modern sunscreen derived from chestnut extract, which had been used in folk medicine for many years (Urbach 2001). Shortly after this revelation, in 1923, Coco Chanel returned from the French Riviera and accidentally tanned her skin, starting the craze of getting tan (BronzeTan.com 2020).

Fast forward to 2023, and we have more sunscreen and sunscreen ingredients than you can count with names that look like they came from an alien language. While not everyone is out trying to get a tan on the beach, everyone is directly affected by the sun's radiation every time they step outside. Fortunately, sunscreen technology has advanced to provide various types of sunscreen that can absorb or reflect the sun's rays, in addition to the wide variety of sun protection clothing that we have, there should be no reason for any of us to get burnt (Purohit 2017).

What seems like a straightforward solution to sun damage to the skin becomes less evident once you investigate the chemicals that make UV filtration possible.

There have been trials on the potential for active ingredients such as Benzophenone-3 (BP-3) to determine if this ingredient causes negative impacts (Watanabe 2015). The review found, though mixed results, altered birth weights and a decline in gestational age (Ghazipura 2017). I doubt any parent thinks that their sunscreen can cause gestational issues. Still, without further research, these products will continue to be sold and applied to the general public while potentially doing unknown harm to them.

(www.behealthynow.co.uk)

While human harm is a considerable concern, sunscreen and water are a pair that usually go together. On a deeper scale, sunscreen doesn’t stay put when applied to our bodies. Many sunscreen companies advocate applying more sunscreen after getting out of the water as it may come off in the water (Purohit 2017). When in the water, fish can bioaccumulate the active ingredients, disrupting endocrine function, altering behavior, and impacting development and reproduction (Lebaron 2022). Unfortunately, not all of these ingredients behave the same, and it is complicated to quantify each chemical's effect on every animal species. Aside from marine animals, studies examining marine algae’s response to BP-3 show decreased chlorophyll content and growth rate (Mao 2017).

Perhaps more commonly talked about is the effect that BP-3 has on corals. Each additional stressor adds to and exacerbates the preexisting problems in a changing climate. This, unfortunately, holds true for corals. Studies have demonstrated that BP-3 can damage all life stages of some species of corals and intensify the problem in the sunlight when most of the BP-3 pollution takes place (Downs 2017). The tourist industry that many island and tropical nations are built on is concurrently destroying the very thing that many tourists are coming to see.

This complexity intensifies the decision-making process when buying sunscreen. It involves not only considering the chemical impact of sunscreen on your body for cancer prevention or sunburn protection but also considering the broader environmental context. The ongoing issue of sunscreen-related pollutants in the environment has prompted some individuals to proactively address the matter, advocating for chemical removal methods directly from the environment.

There has been some success in wastewater treatment plants. BP-3 coming from pharmaceuticals and personal care products. The study used diammonium salt, a synthetic mediator, and acetosyringone, a natural mediator, which removed BP-3 to below a detectable level in just a couple of hours (Garcia 2011). There have also been pushes to use constructed wetlands to adsorb the chemicals or reduce them through biodegradation or plant uptake (Ilyas 2020).

Regardless of how we keep these chemicals from entering the ocean, one thing is certain: it must be done. Fortunately, ad campaigns have been somewhat successful, enacting specific chemical bans leading to lowered detection levels (Miller 2021). Sadly, there are no marketing standards or repercussions for mislabeling a bottle of sunscreen as “Reef Safe.” A study done in 2020 found that of the 52 products with a “Reef Safe” label, 48% of them contained a NOAA-specified “Reef Toxic” ingredient (Chi-Han 2020).

Further digging can reveal ingredients classified as non-hazardous (Miller 2021), but finding products containing only the listed ingredients can be difficult.

Even if you could find ingredients on the list provided in the Miller 2021 paper, that still does not mean that they are 100% reef and organism-safe. Chemicals affect different organisms in various ways, and currently, there is no standardized test that chemicals go through to determine if they are safe. The percentages of active ingredients differ from product to product, making classification more difficult. Is a 25% zinc oxide sunscreen better than a 4% BP-3 sunscreen? Without more research, these questions remain unanswered.

On sunscreen websites, the benefit to humans is frequently embellished and backed by dermatologists. Still, some scientific facts are stated without telling where they obtained their information (gowaxhead.com).

While there is still no clear answer about what sunscreen you should wear on your next outing, a few things are clear. More research is needed that should be performed by the companies that are advocating for their chemical use. Some sunscreens may be a better option such as non-nano zinc-oxide sunscreen, but overall, we must rethink sun protection and emphasize using material sun protection such as long-sleeved shirts, hats, and sunglasses.

(www.prevention.com)

References

BronzeTan.com. (2020, January 30). A Brief History of the Tan. Bronze Tan St. Louis. https://bronzetanstl.com/brief-history-tan/#:~:text=In%201923%20after%20accidentally%20tanning,and%20rebellions%20against%20Victorian%20values.

Chia-Han Yeh, M., Tsai, T. Y., & Huang, Y. C. (2020). Evaluation of ‘“reef safe”’ sunscreens: Labeling and cost implications for consumers. Journal of the American Academy of Dermatology, 82(4), 1013–1015. https://doi.org/10.1016/j.jaad.2019.10.059

Downs, C. A., Kramarsky-Winter, E., Segal, R., Fauth, J., Knutson, S., Bronstein, O., Ciner, F. R., Jeger, R., Lichtenfeld, Y., Woodley, C. M., Pennington, P., Cadenas, K., Kushmaro, A., & Loya, Y. (2016). Toxicopathological Effects of the Sunscreen UV Filter, Oxybenzone (Benzophenone-3), on Coral Planulae and Cultured Primary Cells and Its Environmental Contamination in Hawaii and the U.S. Virgin Islands. Archives of Environmental Contamination and Toxicology, 70(2), 265–288. https://doi.org/10.1007/s00244-015-0227-7

Garcia, H. A., Hoffman, C. M., Kinney, K. A., & Lawler, D. F. (2011). Laccase-catalyzed oxidation of oxybenzone in municipal wastewater primary effluent. Water Research, 45(5), 1921–1932. https://doi.org/10.1016/j.watres.2010.12.027

Ghazipura, M., McGowan, R., Arslan, A., & Hossain, T. (2017). Exposure to benzophenone-3 and reproductive toxicity: A systematic review of human and animal studies. In Reproductive Toxicology (Vol. 73, pp. 175–183). Elsevier Inc. https://doi.org/10.1016/j.reprotox.2017.08.015

Ilyas, H., & van Hullebusch, E. D. (2020). Performance comparison of different constructed wetlands designs for the removal of personal care products. In International Journal of Environmental Research and Public Health (Vol. 17, Issue 9). MDPI AG. https://doi.org/10.3390/ijerph17093091

Lebaron, P. (2022). UV filters and their impact on marine life: state of the science, data gaps, and next steps. In Journal of the European Academy of Dermatology and Venereology (Vol. 36, Issue S6, pp. 22–28). John Wiley and Sons Inc. https://doi.org/10.1111/jdv.18198

Mao, F., He, Y., Kushmaro, A., & Gin, K. Y. H. (2017). Effects of benzophenone-3 on the green alga Chlamydomonas reinhardtii and the cyanobacterium Microcystis aeruginosa. Aquatic Toxicology, 193, 1–8. https://doi.org/10.1016/j.aquatox.2017.09.029

Miller, I. B., Pawlowski, S., Kellermann, M. Y., Petersen-Thiery, M., Moeller, M., Nietzer, S., & Schupp, P. J. (2021). Toxic effects of UV filters from sunscreens on coral reefs revisited: regulatory aspects for “reef safe” products. Environmental Sciences Europe, 33(1). https://doi.org/10.1186/s12302-021-00515-w

Purohit , M. P. (Ed.). (2017, August 1). What type of sunscreen should I purchase?. DoveMed. https://www.dovemed.com/healthy-living/wellness-center/what-type-sunscreen-should-i-purchase

Urbach, F. (2001). The historical aspects of sunscreens. In Journal of Photochemistry and Photobiology B: Biology (Vol. 64). www.elsevier.com/locate/jphotobiol

Watanabe, Y., Kojima, H., Takeuchi, S., Uramaru, N., Sanoh, S., Sugihara, K., Kitamura, S., & Ohta, S. (2015). Metabolism of UV-filter benzophenone-3 by rat and human liver microsomes and its effect on endocrine-disrupting activity. Toxicology and Applied Pharmacology, 282(2), 119–128. https://doi.org/10.1016/j.taap.2014.12.002

Waxhead Sun Defense. (n.d.). Is zinc oxide safe? https://gowaxhead.com/blogs/the-thrive-lab/is-zinc-oxide-safe#:~:text=Zinc%20oxide%20is%20the%20only,and%20best%20active%20sunscreen%20ingredient.

“Wait, you still eat fish?” and other things marine science students are tired of hearing

by Grace Teranishi, MLML Ichthyology Lab

 

As marine scientists and scientists-in-training, we at MLML know we dodged a bullet in the decision against pursuing a career in, say, medicine—a path that inevitably leads to a hypochondriacal aunt listing her symptoms to you at the Thanksgiving table or to a patient of yours asking about his unfortunate toe rash when he spots you at self-checkout. Aren't you also glad you didn't major in studio art, which would have everyone and their mother wanting to hire you to illustrate a children’s book? Yes, we fish people, sponge people, seaweed connoisseurs, and sediment transport enthusiasts have it pretty good, but there are still a few comments and interactions we would prefer not to put up with on a day-to-day basis.

I asked MLML students, "What are you tired of people telling you because they know you are in the marine science field?" Here's what you had to say:

 

Some of you were frustrated that people underestimate the work you do.

1. "What an easy job/degree. You’re so lucky just hanging out at the beach all day." -Dylan, Ichthyology

 

Photo of beach waves at sunset
Credit: Grace Teranishi

 

Others of you have experienced that people vastly overestimate what you can do. 

2. "'Oh you're a marine scientist, you're going to save the world.'

–there's literally no paper I could publish that would suddenly make people take environmentalism more seriously. The change has to come from policy. Also, assuming that the tanks in the [Monterey Bay Aquarium’s] deep sea exhibit are pressurized. They're not." -Alex, Invertebrate Ecology

 

3. "Oh, so you're going to save the coral reefs, right?" -Keenan, Invertebrate Ecology

 

We would love to reverse centuries of environmental exploitation with a snap of our fingers, but unfortunately, that’s not how it works.

 

 

Some expressed fatigue at general ignorance.

4. "Challenging if the megalodon is truly extinct because we've only explored 30% of our oceans." -Sophie, Marine Biology major at SJSU

 

We love a good bad shark movie now and then, but please stop.

 

 

Or fatigue at the nonstop questions not even remotely related to what you actually study.

5. "This one time during a dinner rush I was serving a large table and they asked me if I was in school. Upon finding out I was at MLML, one patron asked me to enlighten the table about the local ecology of the bay. 'Tell us about the canyon!' he said. 'Tell them about the whales!' he said. 'Twas dinner and a show... we were very busy... and I study fish genes." -Nick, Ichthyology

 

6. "I participate in Skype-a-Scientist, where you match with classrooms to talk about your experiences as a researcher. I introduced myself as a student at the Marine Labs with a focus on fish/estuaries/ocean life; I matched with an elementary school teacher who wanted me to answer an eight year-old's questions about platypuses." -Grace, Ichthyology

 

7. "So do you like, train dolphins?" -Jackie, Fisheries & Conservation Biology

 

8. "When you type 'phycology' into a google search and get asked if you really mean 'psychology.'" -Shelby, Phycology

 

9. "What kind of fish is this?" "How long can whales hold their breath for?" "Does toilet bowl water really go down counter-clockwise?" -Victoria, Geological Oceanography 

Photo of black and yellow rockfish and purple sea urchins
Credit: Juliana Cornett

 

People just really love hearing all about the sharks.

10. "It has to be 'Have you ever seen sharks?' when I talk about diving or am spotted with dive gear at a beach.  Sometimes it is difficult to talk about them in a realistic, non-threatening way." -Kameron, Ichthyology

 

11. "Did you hear about the shark attack at [location]? What do you think happened?" -Matt, Phycology

 

Many of you were tired of talking to people about Monterey Bay sea otters and felt that the less charismatic ocean life deserved a little more love.

12. "*Looks at an invertebrate* ‘Wait, but they're not alive though right?'" -Noah, Invertebrate Ecology

 

13. "They always want to talk about sea otters and why they are so important here." -Amber, Vertebrate Ecology

 

14. "I'm tired of people thinking I study fish or mammals... or when people mention how their cousin studied marine biology in undergrad but now she's a *insert random unrelated profession*" -Jess, Phycology

 

There’s more to the ocean than whales and dolphins and otters, people!

Close-up photo of opalescent nudibranch
Credit: Juliana Cornett

 

And on a similar note, marine science encompasses so much more than just biology.

15."People asking what the difference [is] between marine science and marine biology" -Samuel, Ichthyology

 

16. "So you're a marine biologist?"' -Anonymous

 

17. "Everyone assumes I'm a 'marine biologist' when I tell them I'm an oceanographer :-)" -Marine, Chemical Oceanography

Photo of researchers performing a CTD (conductivity, temperature, depth) cast at sea
Credit: Grace Teranishi

 

We are also not all out there telling everyone to stop eating fish. Sometimes it’s quite the opposite! We want to make sure that there’s still fish left in the ocean so we can keep eating them.

18. "Oh so fish science? Wait, do you still eat fish?" -Quinn, Ichthyology

 

19. "I study vertebrate ecology. People usually assume that I am extremely against all forms of fishing. I have a lot of respect for fishermen and want to help them as much as I want to protect endangered marine mammals and turtles."-Kali, Vertebrate Ecology

 

20. “If I eat fish and then [they] get surprised that I do. Of course I do they're delicious." -Konnor, Fisheries & Conservation Biology

 

Currently thinking about the trout I had for dinner last night.

Photo of cooked trout dinner
Credit: Nicholas Kolasa-Lenarz

 

 

And finally, this:

21. "'You will be paid in experience!' -with regard to any unpaid internship 'opportunity'" -Anonymous, Geological Oceanography

 

Thank you everyone for taking the time to respond to this survey!

Fourteen students defend thesis research in 2021!

By Emily Montgomery, MLML Phycology Lab

2021 was a complex year to be a graduate student, with global societal issues demanding our attention and energy alongside our usual scientific workload. The emergence of the COVID-19 vaccines brought with it the hope of being able to safely socialize in-person with our friends and loved ones again. The resilient Moss community was able to return to some in-person activities in the Fall of 2021, including hosting the first lab Halloween party since 2019!

During this rollercoaster of a year, 14 students successfully defended their MLML theses virtually via Zoom. Please join me in congratulating the following students:

  • Ann Bishop, Phycology Lab
  • Taylor Eddy, Invertebrate Zoology Lab
  • Bonnie Brown, Fisheries and Conservation Biology Lab
  • Matthew Jew, Ichthyology Lab
  • Justin Cordova, Pacific Shark Research Center
  • Gregory Bongey, Geological Oceanography Lab
  • Jennifer Tackaberry, Vertebrate Ecology Lab
  • Sophie Bernstein, Ichthyology Lab
  • Rachel Brooks, Ichthyology Lab
  • Holly Doerr, Ichthyology Lab
  • Melissa Naugle, Invertebrate Ecology Lab
  • Kristen Saksa, Ichthyology Lab
  • Jacquie Chisholm, Physical Oceanography Lab
  • Amanda Camarato, Physical Oceanography Lab

Read below for pictures of the graduates, and explore the links to their thesis announcement posts with more info about their projects and the YouTube recordings of their defenses.

Check out posts commemorating past defenders written by MLML alumna June Shrestha: 2020, 2019, 2018, and 2017.

Read More

The other pandemic: linking COVID-19 and climate change

By Grace Teranishi, MLML Ichthyology Lab

Salinas, CA (Summer 2020)

By now we’ve grown somewhat accustomed to the haze and the smell of smoke, the ash that dusts our cars, our patios, our coats. It’s August, night. My friends have invited me over to drink beer and observe the glare of the River Fire ebb and flow over the hills across the highway. Within the week they’ll receive an evacuation order.

With both COVID-19 and environmental crises to convulse the world, this past year has witnessed its fair share of fires—literal and figurative—disrupting homes, livelihoods, social norms, and mental stabilities. Unsurprisingly, we find increasing evidence of how one pandemic (COVID) interacts with and bears resemblance to another, even deadlier one: climate change.

Read More

Recognizing individuals through repeated field encounters

By Kameron Strickland, MLML Ichthyology Lab & CSUMB Image Analysis Lab

Our pursuit for statistical power involves repeated trials and non-trivial sample sizes.  After hundreds of fish dissections or thousands of water samples, big data can become a big chore.  Once exciting field observations are converted to numbers, I find myself occasionally forgetting the amazing individuals we are fortunate enough to study.

I’ve enjoyed photographing both fish and birds for a few years.  Through repeat encounters, I’ve come to recognize specific individuals both on land and on sea.  If you have had the same experience, you will understand the excitement in recognizing these individuals time and time again.  Sexual dimorphism, unique behaviors, and physical markings are all indicators that can be used for identifications.  Here, I provide small anecdotes about some of the individuals I’ve met through my photography.

 

Scarred Kelp rockfish

I just logged my 400th dive in my SCUBA career.  A majority were around the Monterey Peninsula, most being in the Carmel Bay.  While studying microhabitat associations of Kelp rockfish in Carmel, I recorded more than 1,000 observations of the species.  Kelp rockfish display a wide range of color morphs and patchiness patterns, from a ghostly white to earthy greens and browns.  I recognized this specific individual across a few dives due to the distinct white scar its left side.  After an hour of deep depths and freezing temperatures, it was exciting to find this fish hanging around the same patches of kelp.  I’m not sure if the feeling was mutual!

 

Two Vermilion rockfish in Carmel, CA

Just across the bay live two large Vermilion rockfish.  The smaller of the two is much more orange, while the larger one has more complicated silver patches on its body.  These large, vibrant rockfish stand out from the other species on the reef.  When I dove nearly every day during the summer of 2018, I would see these individuals in almost the exact same places.  Because of their large size, I believe these two individuals could have easily outcompeted other rockfish for the best crevices along the rocky reef.  Since 2018, this kelp forest has turned into an urchin barren with only a few opportunistic Macrocystis and Nereocystis fronds remaining.  Yet the Vermilions remain – I just saw one of them last week!  It still feels as if these two fish purposefully come out to greet me on dives.

 

White-tailed kite

During runs, I’ve passed this White-tailed numerous times while it was perched on the same tree.  I’ve made it a mission to return with camera gear and try to photograph it, but have only succeeded twice.  Their bright red eyes have always fascinated me.  If my presence doesn’t scare it off, turkey vultures and crows seem to always chase it away.

 

Anna’s hummingbird in Moss Landing

I discovered this Anna’s hummingbird at a location I frequent weekly for shorebirds.  This individual favors flying back and forth between three perches.  It was shy when I first discovered it, not letting me approach very closely.  I began using my camera’s electronic shutter to shoot silently and minimize disturbance on its natural behavior.  After many weeks of returning to this individual, it has become more comfortable with my camera gear.  It now lets me move closer and will even return to me after flying away.  Over a the past few months, this bird has become a part of my weekly photographic routine; I like to think that I am a part of its week as well!

 

Pair of Eurasian collared doves in Moss Landing

Not far from the hummingbird I visit, two Eurasian collared doves that have claimed a tree as their own.  These two are inseparable.  Although I am no dove expert, I suspect they may be a breeding pair.  Since their tree is near the busy Moss Landing harbor, they sometimes have to other flying fauna.  In my opinion, these goofy doves have one of the most hilarious calls.  Unfortunately they are hesitant to drop down at eye level, which makes it difficult to capture photos.

 

Photographing wildlife is an enjoyable break from the hard science I feel is prioritized during grad school.  These small encounters have highlighted some of the interesting routines and personality traits of my subjects.  I hope you are able to recognize individuals across your scientific endeavors.  Happy research!

Where have all the abalone gone? The impacts of ocean acidification on abalone populations

By Kayla Roy, MLML Ichthyology Lab

 

When you think of sea food what do you think of? Do you picture a fish fillet, lobster bisque, or maybe fish and chips? These are some of the common seafood dishes you can find on the menu at your favorite seafood stop, but have you ever seen abalone steak on the menu? It used to be a common staple eaten up and down the California coast. Now abalone are almost impossible to find not only on the menu, but in the ocean. So why have these animals begun to vanish from our diet and seas? This is due to the many changing oceanic conditions including ocean acidification.

Abalone have disappeared from our diet because the oceans have become too acidic, which has greatly reduced their population size. Climate change, driven by human emissions of carbon dioxide mainly from fossil fuels, is changing Earth’s climate and altering ocean chemistry. One of these changes is ocean acidification, which is a process that makes the ocean more acidic because of an increase in carbon dioxide. Change in acidity impacts marine life like abalone by reducing population sizes through developmental deformities, shell dissolution, lowered reproductive success, and reduced survival. So why do we care about the impact of ocean acidification on abalone and their continued existence in our ocean? Besides their previous inclusion in our diets, abalone contribute to the ocean and to people in many ways.

Read More

Nine students defend thesis research in 2020!

By June ShresthaMLML Ichthyology Lab

2020 was a big year. We saw a global pandemic, protests in support of the Black Lives Matter movement, and wildfires raging across the state. Despite all of this, we had nine students pull through to defend their thesis research in 2020! Please join me in congratulating the following students:

  • Lindsay Cooper, Phycology Lab
  • Kenji Soto, Geological Oceanography Lab
  • Amber Reichert, Pacific Shark Research Center
  • Mason Cole, Vertebrate Ecology Lab
  • June Shrestha, Ichthyology Lab
  • Dan Gossard, Phycology Lab
  • Jacoby Baker, Ichthyology Lab
  • Emily Pierce, Invertebrate Zoology Lab
  • Miya Pavlock-McAuliffe, Physical Oceanography Lab

Please read below to learn a little more about each student's research. As always, please also check out the posts highlighting student research from previous years as well at the following links: 2019, 2018, and 2017.

Special author note: As I am one of the students that defended and graduated this year, this will be my last post for The Drop-In. From writing about classes to conferences and student research, it's been a pleasure writing for this blog. Hopefully someone else will carry the torch forward in the new year to highlight and celebrate the research of graduating students!

Read More

Thesis Defense by June Shrestha – December 9th

 

"Fish pee in the sea: a surprising source of limiting nutrients in California kelp forests"
A Thesis Defense by June Shrestha

The Ichthyology Lab

MLML Live-Stream | December 9, 2020 at 12 pm

Growing up, June always loved being underwater. Long summer days were spent at the local pool in Virginia, where she swam along the bottom pretending to be a SCUBA diver and scouring the “seafloor” looking for treasure: forgotten toys, hair ties, and even a coin or two. Then on a fateful snorkel trip to the ocean with her family, 10-year-old June loved swimming with the fish so much, that she decided that she wanted to be an “Oceanographer Scientist” when she grew up! Mind you, she did not know exactly what an oceanographer did, but she liked that it had the word “ocean” in it, and “scientist” sounded impressive. 

From then on, all of her academic pursuits were focused on reaching her goal of becoming an “Oceanographer Scientist”. In high school, she crashed “Take Your Daughter to Work Day” events at NOAA, conducted extra science fair projects, and even studied Latin for four years in hopes that it would help her learn scientific nomenclature. In college, June majored in Biological Sciences for her B.S. degree at Virginia Tech and learned that she was actually more interested in ecology, not oceanography! She participated on any research project she could involving the words “water”, “fish”, or “snorkel”, and spent many days surveying streams for fishes in the mountains of Virginia.

Now, as June graduates with her M.S. in Marine Science from Moss Landing Marine Laboratories and CSU Monterey Bay, she can finally say that she accomplished her childhood dream. When not conducting research, you can find June SCUBA diving - for real now - within the kelp beds of California.

Thesis Abstract:

In marine systems, fishes excrete dissolved nutrients rich in nitrogen, a biolimiting nutrient essential for regulating primary production and macroalgal growth in the ocean. Often overlooked in attempts to explain the variability in kelp forest productivity, relatively little is known about the magnitude and patterns that drive nutrient excretion from fishes, especially in temperate kelp forests. I investigated the supply of nutrients excreted by the dominant fishes (30 species representing ~85% of total fish biomass) on nearshore rocky reefs in California. Using rapid field incubations, I measured the amount of dissolved ammonium (NH4+) released per individual (n = 460) as a function of body size and developed predictive models relating mass to excretion rates at the family-level. I then combined the family-specific predictive equations with data on fish density and size structure around the northern Channel Islands characterized from visual SCUBA surveys conducted from 2005-2018. Mass-specific excretion rates ranged from 0.01 – 3.45 µmol g-1 hr-1, and per capita ammonium excretion ranged from 5.9 – 2765 µmol per individual per hr. Ammonium excretion rates scaled with fish size; mass-specific excretion rates were greater in smaller fishes, but larger fishes contributed more ammonium per individual. When controlling for body size, ammonium excretion rates differed significantly among fish families with the highest excretion by surfperches (Embiotocidae). On an areal scale, the fish community in the northern Channel Islands excreted a substantial amount of ammonium to the kelp forest (mean: 131.3 µmol · m-2 · hr-1), and spatiotemporal variability (range: 59.84 – 247.9 µmol · m-2 · hr-1) was driven by the establishment of marine protected areas (MPAs), geographic and temporal shifts in the overarching fish community structure, and environmental and habitat characteristics. Results suggest that fish-derived nutrients may provide an important and underrepresented nutrient source to kelp beds, particularly during low-nutrient periods (e.g. seasonal or climatic events), and that fishing may interfere with these nutrient cycling pathways. Areal rates of ammonium excretion – consistent with those reported for tropical reefs, but among the first measured in temperate systems – reveal that fishes may play a critical role in supporting the resiliency of kelp forest ecosystems.

June Shrestha Presents: Fish pee in the sea: a surprising source of limiting nutrients in California kelp forests

Thesis Defense by Jacoby Baker – December 4th

 

"Maternal environment drives larval rockfish gene expression (Sebastes spp.)"
A Thesis Defense by Jacoby Baker

The Ichthyology Lab

MLML Live-Stream | December 4, 2020 at 4 pm

Jacoby has always had an affinity for the water. Even so, he tried to escape the calling of the water and started his undergrad career first in mathematics then moved into biochemistry. Eventually, he couldn't fight it anymore and received his B.S in Biological Sciences with a concentration in Marine Biology from San Jose State University. In his final year of undergrad he found himself interning at NOAA NMFS in Santa Cruz working on a large collaborative ocean acidification and hypoxia project that Dr. Scott Hamilton and Dr. Cheryl Logan were PIs on. Here, he cultivated his interest in researching the effects of climate change stressors on marine organisms, which led to his thesis project. Jacoby is now a Research Assistant at the Monterey Bay Aquarium Research Institute (MBARI) and is applying his molecular background on a project using environmental DNA (eDNA) to help identify organisms residing within Monterey Bay.

Thesis Abstract:

Global climate change is driving shifts in ocean chemistry, which combined with intensification of coastal upwelling, reduces ocean pH and dissolved oxygen (DO) content in the nearshore habitats of the California Current System. Physiological plasticity, within and across generations, might be especially important for long-lived, late-to-mature species, like rockfishes (genus Sebastes), that may be unable to keep pace with climate change via genetic adaptation. Rockfishes exhibit matrotrophic viviparity and may be able to buffer their offspring from environmental stress through early developmental exposure or transgenerational plasticity (non-genetic inheritance of phenotypes). I pre-exposed mother gopher (S. carnatus) and blue (S. mystinus) rockfish to one of four treatments; 1) ambient conditions, 2) low pH, 3) low DO, or 4) combined low pH/DO stressor during fertilization and gestation, followed by a 5-day larval exposure after birth in either the same or different treatment. I used RNA sequencing to determine how the maternal environment affected larval rockfish gene expression (GE). I found that the maternal exposure drove larval GE patterns regardless of sampling time point or treatment. Furthermore, the maternal environment continued to strongly influence larval GE for at least the first five days after birth. These data suggest that rockfish may not be able to buffer their offspring from environmental stressors, highlighting the important role of the maternal environment during gestation.

Jacoby Baker Presents: Maternal environment drives larval rockfish gene expression (Sebastes spp.)

The case of the sea lion: stranding events linked to domoic acid outbreaks

By Sophie BernsteinMLML Ichthyology Lab

When I moved to the Monterey Bay area for graduate school, I found myself most excited to be immersed in a new ecosystem. I couldn’t wait to learn about what the Monterey Bay was known for: the kelp forest. But I never considered the marine life I could see from shore until my scientific diving course, when we would spend several hours a day loading and unloading boats near Moss Landing Harbor. I felt like a little kid in an ice cream store, excited by all the resident sea lions perched on the dock and nearby boats! Needless to say, as an East-coaster, I was in awe. Meanwhile, the Californians who surrounded me did not look twice. Whereas I thought these sea lions were outrageously cute, and had never seen something like this in the wild, my peers simply rolled their eyes at the barking and obnoxious smell coming from the large animals.

Soon enough, I came to realize that California sea lions are a commonly observed, charismatic marine mammal found along the entire California coast. They are top predators in the local ecosystem, and spend extensive amounts of time at sea foraging on a variety of prey items. Common food for these sea lions include anchovies, sardines, squid, and salmon. When not actively feeding, sea lions may be found on shore breeding in groups called rookeries. A single breeding site can be home to several hundred breeding individuals, with one large male dominating the pack! Because they are such large predators who spend time on coastal shores, they are highly visible to the public.

Rookeries are not the only location where sea lions are seen in large numbers onshore. Every few years, sea lions strand in high numbers along the coast. This is particularly noticeable to the public, because when stranded, they displaying incredibly abnormal behavior, such as excessive head weaving, seizures, or even unusually large mortality events. Unfortunately, mass sea lion strandings usually indicate a larger problem occurring in the marine system: harmful algal blooms.

Red tide events, which cause coastal waters to appear red and make the headlines in California newspapers, are one type of harmful algal bloom visible by the naked eye. Another type of bloom that is not necessarily visible in the water itself causes mass sea lion stranding events along the California coast. These blooms are caused by a different type of algae known as Pseudo-nitzschia, and are capable of producing a harmful neurotoxin called domoic acid (DA).  Similar to a canary in a coal mine, California sea lion stranding events are often the first indicator of a domoic acid outbreak.

The most recent DA events were in 2015-2016 and 1998 and both coincided with unusually warm oceanographic conditions. These warm oceanographic conditions are characterized by a decreased supply of cold, nutrient rich water (scientifically known as ‘upwelling’), resulting in water that is comparatively warmer and depleted in nutrients. The changes in upwelling alter how the larger ecosystem functions, by changing the distribution and amount of prey available. Major DA events occur rather infrequently because they require a specific combination of environmental conditions, but when they occur, they are visible to the public. Similar to other threats to marine ecosystems, these stranding events are tied to climate change. The frequency of DA events and marine mortality events may increase as climate change pressures alter upwelling patterns, creating environments prone to toxic outbreaks.

But if sea lions are top predators in California waters, how and why would a tiny algae cell impact them? While we don’t know yet for sure, scientists think sea lions are impacted by domoic acid through the food web. The Monterey Bay ecosystem is amazingly rich. It is home to thousands of fish and invertebrate species, all of which are connected to each other through predator-prey dynamics. For example, a sea lion may eat a squid, which eats smaller invertebrates and phytoplankton. Through this chain, sea lions and the phytoplankton come in contact.

Scientists recognize that sea lions are exposed to DA through these food chain connections. Sea lions are opportunistic feeders who consume a variety of prey items, including anchovies. Anchovies feed directly on algae and other phytoplankton. Since anchovies are important prey items for predators throughout California, the sea lions who consume them might be directly exposed to DA.

Yes, we’re talking about the same anchovy that may be sitting on your pizza! Anchovies are one of the largest fisheries in central California that contribute > 13 million pounds to commercial fisheries. This creates another question: Does DA threaten seafood consumers? Indeed, humans can be exposed to DA through the same food web connections that make sea lions vulnerable.

An important remaining question is: where are sea lions foraging when they’re exposed to DA? Scientists at The Marine Mammal Center have been researching related topics based on the stranded animals they respond to. Researchers have found that DA toxicity in sea lions can result from ingesting prey items which have accumulated DA, but where were these prey items consumed? And what is the relationship between ocean warming events, climate change, and DA outbreaks? With a better understanding of where prey items accumulate DA, monitoring agencies can more adequately test high risk regions, and increase the chances of detecting a toxic event early on rather than waiting for another biological indicator, such as mass sea lion stranding and mortality events.

To learn more about how The Marine Mammal Center is researching and helping during DA stranding events, check out this article.