How is this fish’s diet key to coral reef conservation?

The striated surgeonfish, Ctenochaetus striatus, is an abundant ‘herbivorous’ fish on Pacific coral reefs. Herbivory is a broad category and we are interested in the roles of abundant herbivorous fish that may be eating specific organisms and therefore playing a targeted role in the ecosystem helping corals thrive. Fish that clear, clean, and otherwise alter substrates on coral reefs through their feeding may be making space available for coral larvae to settle and grow. Understanding diets of fish like C. striatus can help with management and conservation of coral reefs, and can help communities that steward these systems make informed decisions about fishing. We plan to use novel technologies (DNA metabarcoding) to determine diet diversity.

Our world’s coral reefs are suffering today under multiple stressors. But they can be resilient, and we can mitigate their stress to some degree. While we may not be able to control climate change immediately, we can limit some of the other stressors, and encourage ecosystem-level connections that can help

Fish are a critical component. These busy members of reefs have functional roles – their activities have an impact on the ecosystem. Understanding their impact can help us develop tools for reef stability and even recovery. If we understand the specific role of an abundant fish like C. striatus (striated surgeonfish), we can co-develop management strategies that promote its positive role.

In June 2022, Steven Pratt & Alessio Bernardi traveled to the Smithsonian Tropical Research Institute (STRI) in Panama City, Panama to continue research on samples collected in Moorea in 2021. 

Substrate, fecal & stomach samples were collected from the fish Ctenochaetus striatus to better understand its feeding ecology. Each sample was filtered in Moorea & frozen for safe storage until their journey to Panama. At STRI, Steven & Alessio used Qiagen kits to extract DNA from 77 samples.

Steven Pratt is a student of Environmental science with a focus on marine systems, at Cabrillo College in Aptos California. He is also a steward and land restoration partner with his tribe, the Amah Mutsun Tribal Band.

Alessio Bernardi is an undergraduate at the University of British Colombia studying molecular biology.

Alessio Bernardi (left) & Steven Pratt (right)

Steven & Alessio’s trip was sponsored by generous donations from our crowdfunding campaign. This research was funded in part by Moorea Coral Reef Long Term Ecological Research .

“We did not know each other beforehand and ended up spending three weeks together. We shared meals, living space, and lab work. It was quite a ride.

One day we took an Uber to the jungle and hiked this research trail. We stumbled upon a sloth returning to the tree tops. This is such a rare site considering sloths only come down once a week to poop. We both got excited to see a sloth so close!

We made the best of our time once we got more comfortable. We met many people doing research, some locals and some from other countries. We enjoyed communicating and adventuring with these people. One day we went with some people from STRI to play volleyball and discovered an extremely welcoming community.

Overall the experience was influential to our lives not only because it forced us to be in an uncomfortable environment, but it demanded a certain level of adaptation. For future jobs and projects the need for adaptation is necessary, and while we may not have finished our work, the experience and community of truly intellectual individuals we found there was extremely important for both our research, and our lives.”