Danielle Dixson is a new faculty member in the School of Biology this year, but she’s not new to Georgia Tech. She spent the previous two years as a post-doctoral fellow in Professor Mark Hay’s lab. Before that she received her Ph.D. from James Cook University in Australia and her B.S. from the University of Tampa. One might say she was brought up with biology in her future … the Minnesota Zoo was right behind her back fence as a kid.

Danielle Dixson: The Minnesota zoo has a special kind of school, kind of like a flagship school, it’s called the School of Environmental Studies. It’s actually at the zoo. So you take all your classes your junior and senior year at the zoo, and they incorporate biology into everything that you’re doing. So I got to take marine biology in Minnesota as a junior, because we got to use the aquariums there.
 
David Terraso: So, is that where your interest in biology began?

Dixson: I’m one of those kids who, when I was five, I said I wanted to be a marine biologist and my parents were like ok. And to anyone who asked, I said, “Oh, I want to be a marine biologist.” They said, “Oh, ok,” thinking I would grow out of it or something. It’s like every little kids dream, but I never changed my mind.

Terraso: Tell us about your research and what you’re looking to do in the next few years.

Dixson: My research in general is how do chemical cues, or smells in the water, give information that cause a behavioral response in fish.  So, what smells elicit certain behavioral patterns, and how does that reflect in community dynamics and settlement selection.
A lot of my work looks at larval fish, or juvenile fishes. And when marine fish reproduce they lay eggs, or spawn into the water column, and the larva, or the eggs, go off into the pelagic environment, and they need to come back to the reef. And what I’m trying to figure out is what chemical cues do they use to decide what reef is a good reef and what reef is a bad reef.

Terraso: Tell us about some of your research projects.

Dixson: So a big project of mine in Fiji is looking at the marine protected areas there, looking at how, if you have a protected area there that’s a very pristine, healthy habitat and you have one that’s a very non-pristine protected area (where it’s essentially trashed because people fish in it and are always in it and there’s runoff and a lot of algae and not a lot of fish) looking at how we can get coral back into that non-protected area. And it seems like the chemical cues may be responsible for the coral and fish larva rejecting that area as a habitat, because it’s so different from the healthy area right next door. So that’s been one of the primary focuses of my post-doc, and I’ll continue doing some of that work with Mark Hay as well.

Another thing that I work on is ocean acidification and the effect that that has on behavior and the effect that that has on mostly larval fishes. I’ve started doing some projects on sharks that I’ll continue while at Tech. I’ve been talking to the Georgia Aquarium about collaborating with them and using some of their shark eggs that they get pretty regularly and treating them with different levels of ocean acidification scenarios that are going to be happening in the near future, within the next 100 years, and looking at how that’s affecting the behavioral response of the animals.

Terraso: Looking further into your career, say 30 years from now, what do you want to have accomplished?

Dixson: I guess 30 years out, I’d like to continue in the same role and be able to have provided the marine community with a much better understanding of how chemical cues work in the marine environment and how the sensory system plays a huge roll in the behavior that comes across with fish and coral larvae.

In the recent past, we’ve been thinking these tiny fish larvae, when they were out in the open ocean, that they were just passive particles drifting around with no say in where they were going. And now in a very short time, it’s been shown, mostly through the ability to use genetics in different ways, that they’re actually going to specific places. We don’t know why they’re going to those specific places. We don’t know how they’re able to manage to get to these places, but clearly their behavior is not passive.

They’re overcoming ocean currents. They’re overcoming all of these obstacles that we thought they would not be able to do. And they’re getting to these locations and their behavior is really the only way you can explain it.

In order to do something, you need a motive to do it, and the sensory cues are what provides them information to decide where to go. So I’d really like to get into how different sensory systems interact. So if you get an auditory cue and an olfactory cue and the olfactory cue is a positive stimulus, but the auditory cue might not sound right, which would you follow? What choices will you make?