Never-Before Seen Video of Yellow Fin Grouper Surfaces

Interdisciplinary team finds that grouper may aggregate in larger groups than previously thought

yellow groupers

MIAMI — May 10, 2011 & mdash; Scientists from the University of Miami (UM) Rosenstiel School of Marine & Atmospheric Science were among a team of researchers that captured Yellow Fin Grouper on video during their illusive spawning aggregation in the United States Virgin Islands last month. Teams from the Rosenstiel School, UM College of Engineering and University of the Virgin Islands joined forces in a multi-disciplinary expedition to the southern shelf of St. Thomas to videotape this rarely seen process.

Due to poor visibility and low light conditions deep underwater, capturing this event has been difficult in the past. Using a remotely operated vehicle (ROV) researchers used a video camera and an acoustic imaging system that documented the process in a non-intrusive way, more than 250 feet below the surface.

Grouper spawn only once a year during a very precise phase of the moon, creating a very narrow window in which studies can be conducted. The film will help scientists to understand the grouper gametes’ initial scattering in accordance to the ocean’s environmental conditions, which determines the fate and transport of the larvae and where they settle.

“The video footage is extremely informative. It is the first time such technology was used to observe mass spawning in the open ocean. We could follow the fish from their gathering spot to the actual spawning location to discover what current conditions they are targeting. This is going to be important for future conservation efforts for not only the Yellow Fin Grouper, but also for other species that aggregate to spawn anywhere in the world,” said Dr. Laurent Cherubin of the Rosenstiel School and member of the research team in the Virgin Islands. “It is essential that we continue to understand their spawning strategy so we can establish sound protective management plans for overfished species.”

Grouper swim together in large stocks during spawning aggregations. Fisherman often use this time to capitalize on the large quantities of fish in a single location, which has decreased populations of several species of grouper at an alarming rate. Aggregations were previously believed to be very small, even in the low 10’s. With the new video, scientists are able to observe a larger aggregation of approximately 800 fish or more, which would indicate conservation efforts have helped the population begin their climb. Efforts to protect the sought-after fish are still required, but perhaps rules that have been put in place are bolstering populations? The team believes further studies of this fishery and its reproductive stage are warranted.

This project was funded through the Virgin Islands Experimental Program to Stimulate Competitive Research (VI-EPSCoR) which promotes the development of the Territory's science and technology resources through multi-disciplinary research and educational programs and leveraged with funds from a prestigious UM Provost Research Award to Dr. Claire Paris.

About the University of Miami’s Rosenstiel School
The University of Miami’s mission is to educate and nurture students, to create knowledge, and to provide service to our community and beyond. Committed to excellence and proud of the diversity of our University family, we strive to develop future leaders of our nation and the world. Founded in the 1940’s, the Rosenstiel School of Marine & Atmospheric Science has grown into one of the world’s premier marine and atmospheric research institutions. Offering dynamic interdisciplinary academics, the Rosenstiel School is dedicated to helping communities to better understand the planet, participating in the establishment of environmental policies, and aiding in the improvement of society and quality of life. For more information, please visit

dr. laurent cherubin •  dr. claire paris •  marine fish •  larval behavior •