By: John Lee

Hi! My name is John (Chi Yen) Lee, and I am a rising junior pursuing an Engineering degree at Harvey Mudd College. This summer, I am very fortunate to have the opportunity to work as a part of the Wrigley Summer Fellowship on Catalina to study robotics and its application to marine biology.

Our research lab (Lab of Autonomous Intelligent Robot) has been collaborating with CSULB’s Shark Lab to track sharks and other marine animals. Currently, most of the tracking is done by human and requires a lot of time and commitment. The goal of our lab is to make the process of tracking marine animals simpler by employing robots to do the tracking instead.

Testing our OceanServer IVER2 Robot at a local pool

The first step in tracking an animal is localizing it. In order localize the fish underwater, we use a tracking system that consists of a pair underwater hydrophones and an acoustic tag. The tag is placed on the fish, and it pings a signal to the hydrophones on the robot at a regular time interval. Using the time of sound flight underwater, the robot is able to deduce the distance of the target (fish) from itself. By accounting for the difference in time the signal hits each hydrophone, the robot can calculate the possible angle that the signal is coming from. With that information, the robot then uses an on board computer to compute the necessary maneuver.

Once the robot localizes the animal, the next step is to follow it. In order to track the animal without altering its behavior, the robot is programmed to navigate around it in a circular fashion at a set distance. The onboard GPS tells the robot its location relative to the target, and a feedback control loop decides the proper rudder angle and speed to directs the robot to its designated path.

The robot fit with hydrophone frames in the testing pool

As of this week, our effort has been focusing on getting the hydrophone system in order. We resolved various issues such as time drift between hydrophone processors, software infrastructure, and particle filtering. Now with most of our system ready to go, the next step will be tracking real fish for the entire month of August. Wrigley’s easy access to the ocean provides us with a perfect testing ground for our robot. Big Fisherman’s Cove is rich with interesting targets like kelp bass and leopard shark. I look forward to implementing and testing our progress on the island!

By: Bonita Lam

Hi, my name is Bonita Lam, and I am a Ph.D. candidate in the USC Biological Sciences department doing research in Professor Kenneth Nealson’s laboratory. This summer I’ve been lucky enough to be supported by the Norma and Jerol Sonosky Environmental Sustainability Summer Fellowship to work on using microorganisms as environmental catalysts.

Our research lab studies environmental microorganisms that are capable of a mechanism called extracellular electron transport (EET). Extracellular electron transport is a way for microorganisms to gain energy from solid substrates such as minerals and rocks. We (as humans) obtain energy through eating food that contains glucose and breathing oxygen, but these microorganisms are amazing in that they can eat and breathe rocks!

A bacteria we isolated using a carbon felt electrode as a source of energy.

Part of the reason why we are interested in investigating these microorganisms, is that they are found naturally in the environment and can potentially serve as catalysts to clean up toxic pollutants. The bacteria that I am working with were actually isolated from marine sediment around Catalina Island – see the photo of my labmates and I collecting sediment for my project (it’s a total team effort). We selected for microorganisms in this marine sediment that were able to conduct EET and got them into pure culture.

My labmates and I out collecting the sediment that we used originally to find the microorganisms we are working with.

My research this summer focuses on trying to optimize the use of these bacterial cultures as natural catalysts. A lot of my work utilizes electrochemical techniques, where I can use electrodes and control them in a way that makes microorganisms use the energy from them to drive other reactions. These other reactions can turn toxic pollutants from their soluble to insoluble form, preventing the spread of them in the environment to facilitate easier clean up. In addition, these microorganisms can also potentially perform bioelectrosynthesis, by using the energy from electrodes to synthesize useful compounds such as methane biogas.

Different conductive electrode materials I’ll be using in my experiments.

My goals this summer are focused on trying to understand how these microorganisms are performing EET and figuring out ways to try to maximize and make this process more efficient. I’m hoping by the end of this summer I can demonstrate that these specific bacteria are capable of converting selenium compounds – which are common contaminants of water – to less toxic forms!

A typical electrochemical experimental set-up where we monitor how the isolates are performing as catalysts.