Learning Limits with the Tiniest of Fishes

SIMON BRANDL, Ph.D.

Brandl oversees a lab that includes researchers from diverse backgrounds, doing research relevant for reefs worldwide.

Interviewed by Christine Sinatra.

How did you start researching small fish like the coral reef fish you study?
As an undergraduate, I managed to connect with a professor in Austria who had done work on tiny little fish called clingfishes. These fishes have a sucking disc on their bellies that they use to stick themselves on the undersides of shells and rocks, but we really don’t know much about them. I kind of fell in love, since these animals have a lot of character and are really quite beautiful when you look closely.

What might your research make clear that we don’t know about yet?
I would like to develop a better understanding of how different ecosystems in the world’s oceans work, specifically with regards to how energy and nutrients move through these systems. Here in Texas, for example, there’s a lot of organic matter and algae in the water, which becomes food for oysters, little crabs, or zooplankton, all of which can be eaten by larger fish. On coral reefs, on the other hand, the water is clear and there’s not a lot of food available. So how coral reefs can manage to support so many large fishes, despite that, is a bit of a mystery still – and also a really important applied problem with the demise of coral reefs. If we don’t know how different reefs function, we can’t really preserve and manage them. I’m particularly interested in the role that small fishes may play.

“These fishes are really living at the extreme.”

Your research group includes scientists with diverse backgrounds from around the world. Is that a coincidence?

A lot of early coral reef research has been called “helicopter science.” What this means is that a scientist from a wealthy country in the Global North travels to a tropical country in the Global South, studies its reefs and leaves with the data. While the ethical side of this is questionable to begin with, it also doesn’t help the management of coral reefs, and it can lead to suggestions that are wildly inappropriate from scientists who aren’t stakeholders in these regions. Investing in young, talented people who have a connection to the locations where coral reefs exist means those researchers may one day be in leadership positions to help make decisions to help preserve the reefs and the services they provide to people. I am trying to be mindful of this with my recruitment of students and researchers.

What do you study in Port Aransas, Texas, where there aren’t any coral reefs?
The oyster reefs all along the Gulf coast actually offer incredible ecosystems for us to study, and in many ways, they’re not too dissimilar from coral reefs. Both of them are built by calcifying organisms and offer a home to countless critters that fuel the productivity of important fisheries species. And as on coral reefs, you get a lot of very small fishes living in the framework built by the oyster, such as little gobies and blennies fish. These tiny creatures have an amazing biology and they include some of the world’s smallest and shortest-lived vertebrates. To me, it’s incredible that a vertebrate animal, which has almost all of the organs and atomical features that you and I have, can squeeze all of that into a body as small as an inch and then only live for a few weeks or months. These fishes are really living at the extreme and in doing so, they feed a lot of larger fish that are important for society.