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Marine Biologist Dr. Tamar L. Goulet Explores Mutualism on Coral Reefs and Throughout our Complex Planet

When marine biologist Dr. Tamar Goulet arrived at the small Caribbean island of Saba a few years ago to give a talk on her coral reef research, she was greeted by a mural reading “Symbiosis: Nothing in this universe exists alone.”

Marine biologist Tamar Goulet underwater in scuba gear
Marine biologist Dr. Tamar Goulet is an AAAS Member and IF/THEN Ambassador. Credit: Yazmin Goulet.

In her tropical field work that ranges from the coast of Mexico to the Red Sea, Goulet – a University of Mississippi professor – focuses on the important symbiosis between corals and algae. Known as a mutualism, it occurs when two different species interact with each other in a way that benefits them both. In the underwater partnership Goulet focuses on, the algae get protection and nitrogen from the coral. And the algae provide photosynthetic products (sugar) to the coral for its growth.

The AAAS Member says symbiosis is essential to healthy marine environments. According to the National Oceanic and Atmospheric Administration (NOAA), about 75% of the world’s coral reefs are threatened by human activities and ecological disruptions. Much of that is due to coral bleaching. When ocean waters warm beyond a coral’s tolerance, its symbiotic algae are expelled, stripping the organism of color and stability.

“When a symbiosis is removed from nature, it leaves a hole.  If the hole cannot heal, other organisms may be affected.  And, like a tower of cards, the whole ecosystem may collapse.  Corals and sea anemones are in symbiosis with single-celled algae that live within them.  If corals die, coral dwelling fish have no home. If corals die, coral dwelling fish have no home. Similarly, if sea anemones perish, anemonefish -- like Nemo -- have no home, and they are eaten. Eventually, the predatory fish have no food to prey on, and they too die,” Goulet says.

Goulet’s research shows that while some coral species are collapsing due to pollution, climate change, and bleaching, others continue to thrive.

“When you stick your head in the water in the Florida Keys, the hard corals are doing really poorly while the octocorals are doing really, really well. My lab has investigated and published on multiple aspects of that,” she says.

Many octocorals have beautiful branching structures, and eight tentacles. These include the delicate looking sea fans. Goulet’s team is studying their biochemistry, symbiosis, as well as the effects that temperature, ultraviolet light, and increased nutrients have on them. The scientists are also determining whether the bacteria in injured colonies are different from bacteria in healthy and non-injured colonies.

One goal of this research is to understand coral reefs and determine the best ways to restore them. From the Florida Keys to Australia’s Great Barrier Reef, that includes interventions such as transplanting and re-attaching coral fragments, to coral farming. Goulet says, like many organisms, the highest mortality is at the smallest stages of growth. So, by jump-starting the natural process, corals with a head start may survive.

Coral reefs provide enormous benefits that touch lives far beyond tropical coastlines.

They provide critical habitat for fish; nurseries for juveniles and spawning grounds for adults. Eco-tourism fuels the economies of many island nations and coastal communities.

Still, Goulet has concerns about the future of corals. While corals and algae have thrived in tandem for millions of years, Goulet says some humans are making self-centered choices that hurt coral reefs. Some current choices are even dangerous to others during the Coronavirus pandemic.

“People were thinking of themselves and not of society. I found it very unsettling, that even in a crisis that is killing human beings, other human beings are not even willing to go out of their way a little bit as far as discomfort and wear a mask, because they didn't think it affected them. Many people (also) don't think about how their actions affect nature, let's say, throwing out a water bottle when they go to the beach and just leaving it on the beach to be washed into the ocean,” Goulet says.

For now, the COVID-19 crisis has put a temporary halt to Goulet’s field research. The University of Mississippi has a travel ban in place because of the pandemic lockdown, and she doesn’t know when she can resume work in the Gulf of Eilat, in the Red Sea off Israel, or the small fishing village of Puerto Morelos near Cancun, Mexico.

Adapting to challenges like this global pandemic is not a new experience for Goulet, the only woman who is a full professor in her department of 21 tenure/tenure track faculty. 

“As a woman in science, it has been a constant struggle. There is still inequity in science, and it's both in terms of being a minority, and also in terms of being treated a certain way,” says Goulet.

That’s why she says her selection into an elite group of women STEM pioneers, as a AAAS IF/THEN® Ambassador, means so much.

“For me, the IF/THEN® Ambassadorship has been a huge validation that I matter, that my efforts are appreciated, that I am a valuable member of the scientific community, and that my voice is heard. And that has been very gratifying and very important at my stage in my career,” says Goulet.

The program shows girls and young women of all backgrounds that they can see a scientist when they look in the mirror. And, Goulet says, that positive energy works in both directions.

“We're the role models for the young generation, but, and this goes back to mutualism, I'm benefiting immensely as well. I'm trying to be this role model, but I'm also getting so much strength,” she says.

Tamar Goulet pictured by a beach.
Marine biologist Dr. Tamar Goulet in the Gulf of Eilat, Red Sea. Credit: Jordan Heiman.