Banca de DEFESA: JESSICA BLEUEL
Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.STUDENT : JESSICA BLEUEL
DATE: 23/02/2024
TIME: 13:30
LOCAL: Departamento de Oceanografia e Limnologia, sala 1 E https://www.youtube.com/watch?v=TPd-DbrWJMo&ab_c
TITLE:
TAXONOMIC, FUNCTIONAL, AND TROPHIC DIVERSITY OF CORALS AND RESPONSES TO THERMAL STRESS
KEY WORDS:
Diversity patterns; environmental gradient; functional traits; fatty acids; predominant trophic mode; autotrophy; heterotrophy; calcification; thermal tolerance; bleaching
PAGES: 110
BIG AREA: Ciências Biológicas
AREA: Ecologia
SUMMARY:
Corals play unique roles and are critically important in reefs, but they are threatened by
rising ocean temperatures causing bleaching events that can lead to loss of coverage, diversity, and reef complexity. Considering that approaches based on functional traits can provide insights into their responses to environmental disturbances, understanding patterns of coral diversity and their traits, as well as their responses to climate change, is fundamental. In Chapter 1, we describe the taxonomic and functional diversity of corals in Brazil, evaluating species composition and the functional space occupied among regions. We observe clustering of eight regions, where Bahia holds the highest species richness and proportion of occupied functional space, both decreasing with distance from this region. Species composition and regional distribution are influenced by environmental barriers and filters and related to coral traits. In Chapter 2, we investigated the variation in concentration and composition of fatty acids in shallow water zooxanthellate corals along the Southwestern Atlantic coast (SWA) to indicate their predominant trophic mode and assess potential geographic variations. Species identity and location explained most of the variation in fatty acid composition in the SWA, associated with photosynthetically available radiation (PAR), sea surface temperature (SST), and particulate organic carbon (POC). The fatty acid composition of Favia gravida, Siderastrea stellata, Mussismilia harttii, and Mussismilia hispida varied among locations, while Madracis decactis, Montastraea cavernosa, and Porites astreoides showed a consistent pattern across all locations. Additionally, based on the concentration of the heterotrophic marker (CGA), P. astreoides was the most autotrophic species, and Mu. hispida was the most heterotrophic coral. Coral growth form is also an important attribute due to the addition of calcium carbonate in the reef environment. Therefore, in Chapter 3, we experimentally assessed the relative contribution of autotrophy- and heterotrophy-based feeding modes on the growth of Millepora alcicornis and Mo. cavernosa, and how they respond to thermal stress. We observed a higher growth rate for M. alcicornis than M. cavernosa. The dissolved organic matter (DOM) feeding treatment initially had a positive influence on coral growth, which did not sustain over time for M. cavernosa and was delayed for M. alcicornis. Thermal stress had little impact on growth and the predominant trophic mode of both species. However, it negatively affected the photochemical efficiency (Fv/Fm) and coloration of Mi. alcicornis (temperature-sensitive). Corals subjected to the DOM treatment were less susceptible and showed greater recovery after thermal stress. On the other hand, the health of Mo. cavernosa (temperature-resistant) was not affected by thermal stress.
COMMITTEE MEMBERS:
Externo à Instituição - RALF TARCISO SILVA CORDEIRO - UFRPE
Externa à Instituição - BARBARA RAMOS PINHEIRO - UFAL
Externa ao Programa - 3257898 - CYBELLE MENOLLI LONGHINI - nullPresidente - 2319234 - GUILHERME ORTIGARA LONGO
Externo à Instituição - MARCELO DE OLIVEIRA SOARES