Monthly Archives: July 2017

Pumping Iron in the Pacific

By: Kenny Bolster

I am starting my third year as a graduate student at USC, working with Dr. Jim Moffett. This is my second summer as a Wrigley Institute Graduate Fellow, and I’m so glad to be back out here. I am an oceanographer, studying broad patterns that span the Pacific Ocean.

I’m especially interested in the way that the availability of iron changes marine ecosystems. On land, there’s usually plenty of iron in the soil for plants to absorb, and then for other animals to eat, so iron deficiency is fairly rare. But in the ocean, most of the iron that’s dissolved will form rust particles within a few hours and sink to the bottom, leaving really big areas of the ocean surface starved for iron.


My summer REU intern Rafi de la Zerda collects a water sample using a pole sampler

This summer, I’m continuing some of my previous work on Catalina, studying how sunlight changes the behavior of iron, and I’m also starting new projects growing microbes that feed an enormous plume of iron coming off the coast of southern Mexico, and collaborating with some other Wrigley scientists to study how Sargassum horneri, an invasive species of seaweed, is impacting Southern California.

To do all of this, we’ve had to develop a lot of exciting new techniques. I’ve developed a new method to measure sunlight breaking up rust in dust particles, and dissolving the iron so that algae can absorb it.


Taking a selfie with the research drone. Hopefully it will pick up bottles of seawater for us.

We’re also experimenting with using a flying drone carrying a small bottle to pick up seawater samples, so that we don’t have to worry about metal on a boat or a dock contaminating the sample. It also means that in my free time, I can get cool pictures and videos of the Wrigley Institute from the air.


A laminar flow bench, used for research when dust could contaminate sensitive samples or instruments

There’s a lot going on, and it’s keeping me very busy. I’ve been helped by the Wrigley Research Experience for Undergrads (REU) program, funded by the National Science Foundation, and have been working alongside one of the REUs on a lot of these projects. In a month, I’m also preparing to go to the Goldschmidt conference, an international meeting of geochemists that’s in Paris this year, where I’ll be presenting this work I’ve been doing here in Big Fisherman’s Cove. And all of this combined is making this summer fly by. How is it July already?

The Summer of Squid

By: Ivan Langesfeld

Here we are at week 5 of the REU (Research Experiences for Undergrads) program, just over halfway done and I’m feeling both excited and sad about it. Excited because with all that we’ve done in the first half I can’t wait to see what is in store for the rest of our time. Sad, of course, because it means we are that much closer to leaving the island. This place that we are calling home has been a welcoming haven, a place where the lunch break entails hitting the cove for a quick swim (with leopard sharks numbering in the hundreds plus a couple bat rays to boot!) before rinsing and returning to work.


Our saltwater flow through tanks in the greenhouse. Catalina’s seawater has to be heated up to 75F for our more tropical squid.

The greenhouse is where I’ve spent most of my time until now, though more and more I’m starting to use the lab facilities. I work on the Squid-Vibrio project with Dr. Josh Troll, something that I’m continually grateful for and constantly surprised with as it has been everything I could have hoped for. Did I mention that we got a first hatching of 47 baby squid last week?!


So here’s a little insight into our project: We’re working with the Hawaiian bobtail squid, a tiny little guy (~2 inches long full grown) who is super interesting as a model for animal-bacterial relationships since it harbors a bioluminescent bacteria (Vibrio fischeri) that it uses at night to counter illuminate its underside against ambient light so that it casts no shadow. A handy trick for avoiding the hungry predators below!


A compiled 3D image showing the innards of a baby squid, including the ink sac and light organ (though they are hard to spot if you don’t know what to look for). I worked on this at the USC Fraser Translational Imaging Center. Just need a microscopy imaging lab at the island now!

We’re studying how this squid responds to heat stress with the aim of understanding how the squid-vibrio symbiosis holds up to elevated temperatures. This has far-reaching implications as global ocean temperatures continue to rise due to climate change and may also give us an idea of how other marine animal-bacterial symbioses will fair (corals and their bacterial partners, for example, are one of many organisms that may be affected similarly).


Dr. Troll (blue shirt) and I looking at newly hatched squid under a dissection scope.

The next critical step to open up the squid-vibrio model for further research is to develop genetic tools to modify the squid. We are narrowing down on the squid’s heat shock parameters (the temperature range where we see a stress response from the squid) in order to then develop genetic techniques that specifically target temperature-dependent gene promoters as a way of selectively activating an introduced gene. Basically, you can tag a gene onto a heat shock promoter so that the foreign gene is expressed only when you want, at a certain temperature.


WMSC at sunset

I can feel how the connections I’ve made so far at Wrigley and through the REU program are going to be something I look back upon as foundational and formative in whichever paths I find myself on in the future. If I continue with research later on, I now know I’m interested in microscopy and bioimaging in addition to my prior interests, which were more along the lines of ecology and working with animals. But aside from shifting interests, the program also spoils us with resources and experiences that open up crazy new doors you never knew would be available. For example, I may end up going into the field next year to collect adult squid in Hawaii with my mentor. I’ve always wanted to go to Hawaii and could have never guessed that the opportunity would arise from working out here on Catalina.

Picture4As for the REU experience in general, I’d advise people to apply to ones you are genuinely interested in but, more so than that, reach out to the person (or people) you’d be working with ask them about their work. That is often a much better way to get an idea of what you can expect your experience to be like than whatever blurb you could find online. If you’re considering an REU or other program at Wrigley, I can’t express how happy I am with the experience of being here as a part of this program.