Banca de QUALIFICAÇÃO: LOUIZE FREYRE DA COSTA CORREA

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : LOUIZE FREYRE DA COSTA CORREA
DATE: 14/11/2019
TIME: 09:00
LOCAL: Sala de Reuniões do DECOL
TITLE:

3-D MONITORING OF CORAL HEALTH: COMPARISONS BETWEEN COASTAL AND OCEANIC REEFS

KEY WORDS:

Siderastrea stellata;Montastraea cavernosa ;Anthropogenic Impacts;Local Dynamics;Coral; Bleaching;Fernando de Noronha

PAGES: 30
BIG AREA: Ciências Biológicas
AREA: Ecologia
SUMMARY:

Coastal reefs are often more prone to anthropogenic impacts in comparison to oceanic reefs due to the proximity to more populated areas. Corals can respond rapidly to these impacts, often presenting negative changes in their health condition depending on the species identity and other abiotic variables such as depth and light exposure. Comparing coral health between coastal and oceanic environments, within the same latitudinal range, may provide insights on how anthropogenic impacts affect these ecosystems and contribute to identify potential refuges for corals. We monitored colonies of the corals Siderastrea stellata (~2m deep) and Montastraea cavernosa (~25m deep) in coastal (Rio Grande do Norte; ~5°S) and oceanic reefs (Fernando de Noronha; ~3°S) in Northeast Brazil, where they are the most important reef builder corals. We monitored coral colonies quarterly for one year (2018-2019) using three-dimensional models generated through structure-from-motion photogrammetry, from which we obtained coral health indicators (bleaching, mortality, diseases and algal overgrowth). Our 3-D model approach revealed that both monitored species are on a good health state in coastal and oceanic reefs, with no record of intense bleaching over the monitored period. Indicators were overall stable over time but they varied more in oceanic than in coastal reefs, with some variation among sites. Colonies of S. stellata, for instance, were on average heathier in coastal than in oceanic sites, which may be related to differences in temperature and light conditions between these areas (Coastal reefs: ~27°C; 2,000-3,000 lux; Oceanic reefs: ~28°C; 4,000-6,000 lux). Another important driver was a massive burial event in one of the oceanic sites, which covered 50% of the colonies of S. stellata for three months. Colonies recovered well, indicating high resilience potential, an important trait to one of the main reef builders in Brazil. The health condition of the corals M. cavernosa was stable and corals in all monitored sites presented on average 80% of their surface area in healthy condition. Temperature and light were also similar and relatively constant in deeper coastal and oceanic reefs (~26°C; 5,000-6,000 lux), indicating this is a more stable environment. Coral health were more affected by variation in local characteristics of the ecosystem than by the proximity to human impact, indicating that local temporal dynamics need to be accounted when assessing the response of corals to human impacts.

BANKING MEMBERS:
Externa à Instituição - MARIANA MITSUE TESCHIMA - UFRJ
Presidente - 2319234 - GUILHERME ORTIGARA LONGO
Interna - 2412921 - JULIANA DEO DIAS