Banca de QUALIFICAÇÃO: VALBERTH FRANCISCO NUNES COSTA

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : VALBERTH FRANCISCO NUNES COSTA
DATE: 09/02/2023
TIME: 14:30
LOCAL: Remoto através de plataforma google meet
TITLE:

Influence of inorganic nutrients on the occurrence of bleaching in the hard coral Siderastrea sp. 

KEY WORDS:

coral reef; oxidative stress; monitoring; pollution.

PAGES: 38
BIG AREA: Ciências Biológicas
AREA: Ecologia
SUBÁREA: Ecologia Aplicada
SUMMARY:

Factors on a global scale such as acidification and warming of marine waters have increasingly threatened reef ecosystems by causing major coral bleaching events. Studies on nutrients of continental origin as pollutants in reef environments are recent and little is known about the effects they can have on the coral community. To assess the impact of inorganic nutrient input on coral reefs, colonies of the stony coral species Siderastrea sp. healthy, weakly bleached and bleached, in 2 exclusion zones or no-takes, in the coral reefs, Maragogi (A) and Japaratinga (B) of the Environmental Protection Area Costa dos Corais, AL, in periods of rain and dry season. Colony tissue was extracted to quantify the activity of the antioxidant enzymes Catalase, Superoxide dismutase, Glutathione S-transferase and lipid peroxidation levels. Surface water samples were also collected for the analysis of physical-chemical parameters and the concentration of inorganic nutrients at 4 points of a transect perpendicular to the beach, from the mouth of the rivers to the reefs. To verify the influence of rivers entering the reefs, satellite images were used to characterize the plumes from the rivers close to the studied reefs, calculating the surface area and the reach of the plumes in the collection periods. The Salgado River had the greatest reach of the plume to reef B, with the highest values of ammonia and nitrite over the reef in the rainy season. The highest values of antioxidant enzyme activities (CAT, SOD and GST) were also recorded in B in the same period for healthy, weakly bleached and bleached colonies. The increased lipid peroxidation after the rainy season indicated the existence of oxidative stress in B. Through the DistLM analysis, it was verified that the ammonia concentration was the parameter that best explained the variation in the IBR values, confirming the occurrence of stress and bleaching in corals, due to inorganic nutrient input related to river discharge. It is suggested that the IBR is an effective tool in monitoring coral health.

BANKING MEMBERS:
Interno(a) - 1265581 - LAZARO WENDER OLIVEIRA DE JESUS
Interno(a) - 1544255 - TACIANA KRAMER DE OLIVEIRA PINTO
Externo(a) à Instituição - JOSE SOUTO ROSA FILHO
Externo(a) à Instituição - RICARDO JESSOUROUN DE MIRANDA