Award: OCE-1756678

Collaborative Research: Pattern and process in the abundance and recruitment of Caribbean octocorals Lead scientist: Peter J. Edmunds Project overview. This project addresses the state of Caribbean reefs in US waters through a 4-year analysis of marine communities along the south shore of St. John, US Virgin Islands. The project focuses on the coral reef crisis that describes the dramatic death of stony corals, the loss of fishes, and the increased abundance of algae, but it focuses on a lesser known aspect of these events: the increasing abundance of soft corals known as octocorals. We leveraged one of the longest running analysis of coral reef health extending from 1987-present to implement an octocoral overlay that began in 2013 with a three year NSF award and was extended by the present award from 2018?2023. The objectives were to describe how octocorals are taking over shallow Caribbean reefs, to identify the mechanisms allowing them to do so, and to evaluate how these mechanisms will project forward to determine how these reefs will function in the future. Intellectual merit. Given that many coral reefs have undergone an unprecedented decline in abundance of stony corals and fishes in the last 50 years, this project sought to understand how the organisms remaining will structure the reefs of tomorrow. We focused on soft corals as our initial work suggested these were the winners on reefs affected by storms and warm water that have been killing stony corals and preventing them from recovering, in part by allowing algae to smother reef surfaces. Through detailed analyses conducted underwater every year for five years, we have shown that soft corals are both more resistant and more resilient to the changing marine world than their stony coral counterparts. By being soft and flexible, octocorals survive the effects of severe storms better than stony corals, and when growing as juveniles on the sea floor, their soft skeletons allow them to rapidly grow and to quickly extend above the algae covering the reef. When extended off the floor and into the seawater, octocorals form underwater forests much like the dense stands of trees forming forests on land. Beneath the canopy of the interlocking branches of octocorals, seawater flows more slowly, shady conditions are created, and a much different habitat is created compared to the open reef. Within this habitat, the animals on the sea floor seek refuge and develop communities differing from the open reef, and in the water column, fishes seek refuge and feed on the animals beneath the octocoral canopy. Importantly, the canopies trap octocoral babies close to their parents, allowing them to reinforce their communities by thriving and contributing to the dense forests. Together, our studies suggest that fleshy octocorals constitute a new normal for Caribbean reefs that are likely to persist for decades. This is a more positive view than the popular interpretation of the coral reef crisis, but critically, octocorals cannot replace the wave resistant structures produced by stony corals and which have provided habitat for organisms and have protected our shores for millennia. Broader impacts. The future biological world will be different from the one of the recent past, and our children will inherent the problems we have created. It is critical that we train them to address these problems, and the opportunities created within this award are a means through which this outcome can be realized. We have engaged young stakeholders at multiple levels through hands-on, real world experiences involving natural history and science opportunities in the US Virgin Islands. This award has created opportunities for undergraduates, graduates, and high school teachers to work in the remote corners of the Virgin Islands National Park, and to deliver their experiences to the instructional environmental in California. The opportunities have culminated in opportunities for science, education, and career development that engage students in California in marine biology, coral reef ecology, and climate change issues of relevance to the immediate future. Last Modified: 04/03/2023 Submitted by: Peter J Edmunds