Facilitation Mechanisms in Rhodolith Beds: From Formation to the Promotion of Associated Biodiversity

• Grant number: 24/18865-2
• Support Opportunities: Regular Research Grants
• Start date: April 01, 2025
• End date: March 31, 2028
• Field of knowledge: Biological Sciences - Botany
• Principal Investigator: Guilherme Henrique Pereira Filho
• Grantee: Guilherme Henrique Pereira Filho
• Host Institution: Instituto do Mar (IMar). Universidade Federal de São Paulo (UNIFESP). Campus Baixada Santista. Santos , SP, Brazil
• Associated researchers: José Juan Barrera Alba ; Vinícius Ribau Mendes

Abstract

The aim of this proposal is to investigate the mechanisms by which rhodoliths, structures formed by coralline algae, play a key role in facilitating and promoting marine habitats, including so-called facilitation cascades. Rhodoliths are often described as "ecosystem engineers" because they modify the environment by creating three-dimensional structures that promote high species diversity associated with the habitats they form (i.e., rhodolith beds). Despite the recognition of their importance, gaps remain regarding how this facilitation occurs across different spatial and temporal scales, what specific biological interactions are involved, and how environmental changes, such as increasing temperature and ocean acidification, may affect these dynamics. This research proposal, led by Dr. Pereira-Filho, aims to fill some of these gaps, building on a long trajectory of studies in this field. The proposer has already led FAPESP-supported projects addressing the biodiversity of reef habitats, including detailed studies on the dynamics of rhodolith beds and their ecological significance. These studies have provided a solid foundation for formulating the central questions of this proposal, which aim to further understand some of the mechanisms by which rhodoliths promote biodiversity in marine environments. The research intends to combine experimental field approaches with laboratory analyses to identify the species associated with rhodoliths, quantify the biological diversity of these communities, and determine how environmental variables influence the facilitation mechanisms promoted by these foundation species. Material collection will primarily take place at newly discovered beds in the State of São Paulo. We will then utilize metabarcoding techniques to more accurately assess the composition of biological communities, as well as their ecological interactions. Additionally, the study will evaluate the impact of climate change and environmental degradation on certain ecosystem functions of rhodoliths. Laboratory-based experimental models will be used to simulate conditions of ocean acidification and warming, with the goal of observing how these factors influence rhodoliths' ability to sustain associated biodiversity. The proposed research is not only relevant for advancing scientific knowledge but also for training specialized human resources in marine ecology, an area in which the proposer has been actively involved. The proposal stands out for its innovative and multidisciplinary approach, combining field experimentation, molecular analyses, and the use of geoscience tools to investigate the mechanisms by which rhodoliths form and modulate local/regional biodiversity. The relevance of this research lies not only in filling critical gaps in scientific knowledge but also in generating essential information for the conservation and management of marine ecosystems threatened by human activities. (AU)