There are few times that I would willingly wake up while it is still dark outside. The day of our ichthyology field trip aboard the R/V Point Sur was one of those days. Not only would it be my first time aboard the Point Sur, it would also be my last before its retirement after 28 years of service at Moss Landing Marine Labs. Suffice to say, I was pretty excited to have this opportunity.
With oceans covering over 75% of Earth’s surface, nearly one billion people depend on seafood for sustenance. As more people continue to add seafood into their diets, our seafood resources are becoming depleted. Some seafood such as bluefin tuna are very valuable, resulting in unmanaged fisheries. To keep up with the demands and profits, products are purposely being mislabeled in hopes that the consumers will continue buying these products. Today, around 25 – 75% of the seafood we consume is mislabeled. This is an alarming issue, as seafood fraud encourages increased illegal fishing activities and impairs consumers right choices in seafood and can impact our health.
When Jacques-Yves Cousteau gave the world its first video footage of the ocean in color, he named this documentary The Silent World. Perhaps as a result, most of us think of the ocean as a quiet refuge, punctuated by occasional humpback whale songs or clicks from a passing pod of dolphins. In recent years, scientists have dipped microphones into the water and discovered that this could not be further from the truth.
Sound travels four to five times faster in water than in air, making it an efficient communication medium for ocean-dwelling animals. Fish larvae track the sounds of a coral reef to locate this source of shelter and food. Shrimp stun their prey and defend themselves using a noisy popping sound emitted by their pincers. Even baby sea turtles produce high pitched calls in their nests, possibly to coordinate hatching or their rush to the sea.
In some marine species small adjustments in pitch and tone signal specific information about breeding or foraging. Male bearded seals in the Arctic alert nearby females that they are ready to mate by producing long trills and whistles as they surface. These vocalizations could also indicate the breeding fitness, or quality, of the male to his potential mates. Bearded seals mate far from land; without these broadcast calls, two receptive partners might never find one another. Listen to one of these calls here.
Marine scientists have only recently begun to conduct research on ocean sounds, and we still don’t know the origin of many noises recorded in the marine environment. A forty year old acoustic mystery was solved this year when an Antarctic minke whale was recorded making the “bio-duck” sound. Listen to the bizarre quacking sound, first recorded by navy sonar operators, here. While we finally know the source of this sound, we still don’t know how or why it is produced. We are left with more questions than answers, but for marine scientists this uncertainty only makes the emerging field of acoustics more exciting.
Next semester, Moss Landing Marine Laboratories will welcome a new faculty member: Dr. Birgitte I. McDonald. She is replacing Director Jim Harvey as the new head of the Vertebrate Ecology Lab. Gitte agreed to answer a few questions about herself in advance of her much-anticipated arrival!
Q: How did you first get interested in physiology and working with "air breather" marine vertebrates?
A: My interest in marine animals started at the age of 7 on a family trip to San Diego where the highlight of the trip was a trip to Sea World. This love of the ocean continued, leading me to study at UC Santa Cruz because of the opportunities for undergraduates to get hands-on experience through field classes and volunteering. As an undergraduate I volunteered at Long Marine Lab for the Pinniped Research in Cognition and Sensory Systems project, took many field courses, and volunteered for graduate students. Some of the most exciting field work I helped out with as an undergraduate was harbor seal captures with Jim Harvey and his students. The more I worked with marine mammals the more excited I got.
My love of physiology came a little later. When talking with Dan Crocker, my master thesis supervisor, about a potential masters project he suggested that it would be good if I expanded my “took kit” by adding a physiological component to my project since most of my previous experience involved animal behavior and ecology. I thought that was a great way to look at grad school – as an opportunity to learn new techniques and subjects - so I followed his suggestion. I am glad I did, because the more physiology I learned the more I loved it. I had always been amazed by the ability of marine mammals and birds to thrive in the marine environment and by studying physiology I was starting to understand how they were able to do it.
Q: Where are you now and what are you working on?
A: Currently I am a NSF postdoctoral fellow at Aarhus University in Denmark working with Peter Madsen and Tobias Wang studying the diving physiology and energetics of harbor porpoises. I have just finished a project studying the diving heart rate in captive porpoises using modified D3tags that can measure heart rate in addition to recording sound, acceleration and pressure. This has allowed me to look at how porpoises regulate their heart rate in relation to dive duration, activity and feeding behavior. We are planning on deploying these tags on wild porpoises as soon as the field tag is ready. I plan to maintain this collaboration after I start at Moss Landing so there may be opportunities for students to use this specialized tag to studying diving physiology and energetics in wild animals.
Q: What new areas of knowledge do you bring to the Vertebrate Ecology Lab, and MLML as a whole?
A: I bring my expertise in physiological ecology of breath-hold divers. One of many reasons I am excited for the position at Moss Landing Marine Laboratory is because of the potential collaborations with the faculty. My research focus on energetics and diving physiology complements the research conducted by the existing faculty, while my expertise will provide new areas of concentration.
Additionally I hope to continue to conduct research in the Antarctic. I am excited about the possibility of introducing students to research in polar environments.
Q: What makes you most excited about joining MLML?
A: There are so many reasons I am excited about joining MLML it is hard to pick the top reason. I am excited to establish a research program taking advantage of the close proximity of the marine vertebrates located along the Pacific Coast. This will allow me to combine my love of field work and teaching by developing courses that provide students with a strong background in the fundamentals, while giving them opportunities to get hands-on experience.
Q: Do you have any special skills outside of marine science that we might like to hear about?
A: I am not sure if it is a skill, but I enjoying figuring things out. If there is a problem or something is broken I think it is fun to try to fix it. It is amazing what you can do with the help of google. I can’t promise the outcome will be the most beautiful, but it will usually be functional. I have found this skill (or stubbornness) useful in the field.
Q: When will you be moving back to the United States?
A: I fly back to San Diego on December 30 and plan to move up to Capitola the first week in January.
We can't wait to start working with you!
Some of you may have been following the blog way back in March, when the “Baja class” traveled to the Gulf of California for two weeks in the field (as a refresher, you can check out the previous posts here and here). Jackie promised some photos and stories from the trip, so I’m going to highlight my particular research project down there and toss in a few of my own photos (better late than never, right?)!
Panoramic view from our campsite on the beach at Bahia de Concepcion, our second of three overnight stops in Mexico on the way down to El Pardito.
Our trip wasn't all marine science! We stopped in the desert on the way down for a natural history lesson from our knowledgeable professors, where we learned about desert ecology and geology!
El Pardito provided some stunning views of the sunrise from the top of the island.
Maybe we'll have to put together a full-on photo post from everyone's photos of the trip, but for now, let's talk science! For my project, I studied the grazing behavior of herbivorous parrotfishes around El Pardito. Parrotfishes inhabit mostly tropical waters and are well-studied on coral reefs, because they graze down algae that can outcompete the reef-building corals - and also sometimes consume the corals themselves. However, their range also extends up into the Gulf of California and other subtropical areas where their role in the ecosystem hasn’t been studied as well. Therefore, for my project, I sought to collect preliminary data on the grazing behavior of these fishes.
To do so, we (myself and other students/instructors in the course – gotta have dive buddies!) followed individual parrotfish around on SCUBA and recorded what they were biting (e.g., fleshy algae, calcified algae, coral, etc.), how frequently they bit each item, and how big their bite scars were. In addition to feeding behavior, we also noted any interactions with other fish. For example, we noticed that some parrotfish chased one another, with the larger individuals being the aggressors. We did this for almost 200 individual fish, spread across four species (we spent a LOT of time underwater), so we were able to collect some good data! The following are some photos of the four species in question (credit goes to Dr. Scott Hamilton for the great photos!).
Scarus ghobban, the bluechin parrotfish (can you guess how it got that name?), grazing on small, filamentous algae (Photo: Scott Hamilton)
The azure parrotfish, Scarus compressus, another common parrotfish at El Pardito (Photo: Scott Hamilton)
The bumphead parrotfish, Scarus perrico. Kind of goofy-looking, but certainly has charisma! (Photo: Scott Hamilton)
The bicolor parrotfish, Scarus rubroviolaceus, with some small sergeant majors in the foreground (Photo: Scott Hamilton)
Overall, the trip was a big success, as all the students were able to complete awesome projects, and we all gained firsthand experience in conducting field work in a remote setting. Not everything went according to plan, but everyone adapted on the fly and made it work. I know that I'm looking forward to seeing what the next "Baja class" will accomplish!
One of the great things about being a student at Moss Landing Marine Laboratories is going diving with your fellow students. You get to see what they are studying and hopefully get some good karma or pay them back for helping you out. I was able to get back in the water after a couple months of drying up on land and dive with Devona Yates.
She is interested in predator-prey relationships and how predatory fishes can have cascading effects on lower trophic levels as they consume invertebrate prey. This cascading effect may differ inside and outside Marine Protected Areas (MPAs), as it appears MPAs may have different, larger, and more abundant predatory fish. Devona is using tethering and survey methods to quantify mortality of these invertebrates and how that may vary as a function of MPA status. It will be interesting and exciting to look at these MPA effects on the survival of these important prey sources for fishes. We use MPAs as a way to protect and increase important ecosystem members we depend on for food and are necessary for maintaining ecosystem function. Predator depletion and recovery may cause changes that were much more complex than we had thought.
(LOOK) Here is a link to a short video clip of the dive, even harbor seals are interested in science.
Those of us working on the ballast project in the Biological Oceanography lab are closely tied with the Cal Maritime Academy and their training ship, the Golden Bear. So, wherever the ship goes, we go! This summer’s training cruise for the cadets took the Golden Bear across the Pacific from San Francisco, California to Busan, South Korea, then throughout the South Pacific and eventually to the island of Saipan. One of our team members, Marilyn Cruickshank, volunteered on the trans-Pacific crossing, gathering surface water samples along the way and conducting a variety of assays to get an idea of the biomass out in the open ocean.
Once in Busan, the rest of our team joined Marilyn to test the ballast water treatments systems currently onboard the Golden Bear. In order to determine if the treatment systems are truly effective, it is important to test in environments that are challenging enough and have a high number of organisms. We were able to conduct a few tests in the productive waters near South Korea and once again when the ship took a quick detour to Manila Bay in the Philippines.
When we weren’t testing ballast treatment systems, the team continued surface water sampling and analysis of biomass in the waters of the South Pacific. Specifically, we were interested in the new ATP measurement method that Jules Kuo developed as part of her thesis project in comparison with the traditional oceanographic ATP measurement methods that have been used for decades.
Our trip concluded in Saipan, where we were able to enjoy a little time off to snorkel in the beautiful waters surrounding the island. The ballast team flew back to California but the Golden Bear will continue sailing throughout the Pacific. Later this summer, we will re-board in southern California for another round of tests!
On June 5th, members of the Marine Pollutions Studies and Chemical Oceanography Labs under the direction of Dr. Kenneth Coale, began a week-long journey on the R/V Point Sur to investigate the recent findings of mercury in coastal marine fog. Dubbed “The Fog Cruise”, the crew and science party aboard sampled near and offshore waters using oceanographic tools for signs of methylmercury (MeHg), from deep sea sediments to fog above the sea surface.