ENSO 2023-24: BLEACHING IMPACTS ON GAMETOGENESIS OF THE ENDANGERED MUSSIMILIA HARTII AND MILLEPORA ALCICORNIS

• Grant number: 24/11137-1
• Support Opportunities: Scholarships in Brazil - Master
• Start date: November 01, 2024
• End date: February 28, 2026
• Field of knowledge: Physical Sciences and Mathematics - Oceanography - Biological Oceanography
• Principal Investigator: Miguel Mies
• Grantee: Arthur Loures Choucair Rodrigues de Oliveira
• Host Institution: Instituto Oceanográfico (IO). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

The consequences of reef-building coral bleaching extend beyond mortality of individuals, compromising reef stability. Reproductive aspects, such as gametogenesis, can be adversely affected by severe stress events, ultimately impacting the population dynamics of these organisms. In the Southwestern Atlantic, information about the consequences of climate stressors on coral reproduction is still scarce, even for functionally important species like the endemic coral Mussismilia harttii and the hydrocoral Millepora alcicornis. A widespread bleaching event related to the 2023-24 El Niño Southern Oscillation is expected in the Brazilian province, putting the populations of these species at risk in certain coastal regions. Thus, this study aims to investigate the effect of bleaching on the gametogenesis of Mu. harttii and Mi. alcicornis by comparing bleached and non-bleached colonies using histological techniques. It is expected to find: (i) a loss in the synchronicity of gamete stage formation, with bleached colonies showing a delay compared to non-bleached ones; and (ii) differences in the production and size of mature gametes between the health conditions of the colonies, especially for Mi. alcicornis. These results have potential relevance for refining conservation and management efforts for these species along the Brazilian coast, as well as providing new insights into their reproductive aspects.