Award: OCE-1923962

Coral reefs are one of the most economically valuable ecosystems in the ocean, and understanding the processes sustaining them is critical to their management and delivery of ecosystem services. The seawater around coral reefs contains dissolved organic matter (DOM), a complex pool of organic nutrients such as amino acids, vitamins, and other diverse compounds which affect the health of coral reefs. The composition of DOM on coral reefs is linked to both the composition of free-living microbes in the seawater and to the nutrition of filter-feeding organisms, such as corals and sponges. Despite the prominence of sponges within coral reef ecosystems, virtually nothing is known about their contribution to DOM and broader reef health. In this project, we advanced knowledge about how sponges process DOM and contribute to the growth of reef water microbial communities. Through experiments, we showed that sponges transform the composition of the DOM pool in a species-specific manner. We also demonstrated that sponges enhance reef water microbial growth. Further, our results were the first to demonstrate that sponge-produced DOM is incorporated by reef-building corals, potentially contributing to the success of these organisms that build the reef framework. This project contributed to the training of undergraduate and graduate students and a post-doctoral scholar and was incorporated into student theses. Results were disseminated to scientific audiences through publications and conference publications and were also presented in accessible languages to K-12 and public audiences.

 

Overall, this project provided fundamental understanding of how sponges contribute to the base of the coral reef food web. As coral reefs are continuously declining in health state,  this understanding is necessary to predict changes to reef microbial food webs and is thus essential for scientists, reef managers, and policy decision makers.

 

Last Modified: 05/29/2025
Modified by: Amy Apprill