Dr. Lisa Ah Shee Tee, Marine Biologist: "Studying Sea Slugs is Imagining Tomorrow's Treatments"

Dr. Lisa Ah Shee Tee, a marine biologist and Senior Project Manager at Reef Conservation, dedicates her career to the protection of seagrass beds, the creation of voluntary conservation zones, and the study of coral bleaching using satellite data.

Lisa, why do you love the ocean?

The ocean is not just my research field; it's also a source of inspiration because I come from a village – Baie-du-Tombeau – where the sea is part of my daily life. This proximity to the ocean has shaped my journey in scientific research.

I love the ocean because it is vast and calming. It's almost like another world where every dive or observation reveals different ecosystems and fascinating marine life. It inspires me, fills me with wonder, and pushes me to understand the nature around us.

However, it also saddens me to see its beautiful colors fading over time. In Mauritius, as elsewhere, coral bleaching, pollution, ocean warming, and human pressures are weakening our reefs and ecosystems. This vulnerability reminds me daily of the urgency to protect our ocean and its biodiversity.

What do you feel when you are at the bottom of the ocean?

For me, the sea is a space of freedom and curiosity. When I am in the water, I feel like I am diving into a separate universe where every color, every movement, or every little creature captures my attention and amazes me. It gives me a sense of calm and fascination, and reminds me why I love spending time exploring and protecting this environment.

Since when have you been diving?

I started diving in 2018 as part of my PhD. Once I submerged, it became hard for me to stop! (laughs) It’s a hobby that requires some investment, but every dive is truly worth it.

Photographing small sea slugs has made my immersion in the ocean even more exciting. I am really lucky to have a job where I can dive almost every chance I get, combining work and pleasure.

What lagoons or reefs have you explored so far?

For my PhD, I mainly explored the lagoons in the west and southwest of Mauritius. As part of my work, I had the opportunity to discover many sites around the island, each with its characteristics and surprises. Even shallow sites can reveal fascinating discoveries, like small marine creatures that often go unnoticed.

What attracted you to the study of sea slugs for your PhD?

What fascinates me about sea slugs is their ingenuity and diversity. Some have lost their shell, while others retain a reduced or internal part. Some can even reuse energy from the algae they eat to survive and regenerate parts of their bodies. Their vibrant colors, tiny size, and camouflage talents make every observation magical.

What is a sea slug?

Sea slugs, or opisthobranch mollusks, are small, colorful, slow, and harmless marine animals. Unlike their snail cousins, many have lost their shell or only retain a small internal remnant. Their unique appearance and bright colors make them highly photogenic creatures, sought after by divers and underwater photographers.

What can you teach us about them?

There are nudibranchs, which are often the most well-known for their vivid colors and stunning shapes. There are two main types of nudibranchs: those with gills arranged in a circle on their back, called "dorids," and those whose back is covered in "cerata," which are permanent structures used for respiration called "aeolids."

Then there are the Head-shield Slugs, characterized by a wide, flattened head shaped like a shield. This unique head allows them to dig through sand or soft sediments in search of food like small invertebrates or algae.

Next, we have Sea Hares that can release colored ink for defense. They get their name from two structures on their head called "rhinophores" that resemble rabbit ears. Unlike many other slugs, their muted colors – reddish, brown, or greenish – often blend in with the plants they graze on, making them true experts in subtle camouflage.

The Side-gilled Slugs are marked by their unique side gills and ability to produce chemical secretions for defense. Some species still possess a small reduced internal shell, a remnant of their ancestors. Meanwhile, the Sacoglossans are herbivores capable of storing cellular structures from the algae they consume and producing part of their energy, similar to plants.

These extraordinary adaptations, including shell loss, camouflage, defense strategies, and unique energy capabilities, make sea slugs one of the most fascinating and diverse groups of marine mollusks.

Why is it crucial to study them?

Sea slugs hold significant scientific importance. Some, like Aplysia, have contributed to fundamental discoveries about memory and the workings of the nervous system. However, they are primarily recognized for their pharmacological potential. Several species produce or concentrate bioactive molecules from their food, currently studied for their anticancer, antimicrobial, or anti-inflammatory properties. These marine compounds are already inspiring promising avenues for new medications. This is why it is crucial to study them.

In summary, sea slugs are both sentinels of the reef and vital actors in its balance, as well as a precious source of scientific and medical innovation. Understanding them means better protecting our ecosystems and possibly discovering tomorrow's treatments.