Banca de DEFESA: VITORIA ERICA DIAS AVELINO DA SILVA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : VITORIA ERICA DIAS AVELINO DA SILVA
DATE: 27/02/2026
TIME: 09:00
LOCAL: Google Meet (meet.google.com/vor-yxta-vzu)
TITLE:

Plastic pollution as a new pathway to ocean acidification and disruption of the carbonate system.

 

KEY WORDS:

DIC; aragonite saturation; calcification; scleractinian corals; plastic degradation.

PAGES: 49
BIG AREA: Ciências Biológicas
AREA: Ecologia
SUMMARY:

Ocean acidification (OA) and plastic pollution (PP) threaten coral reefs, which are essential to biodiversity and ecosystem services. Acidification reduces the availability of carbonate ions in seawater, which are critical for coral skeleton formation. Plastic degradation may intensify this process by releasing CO2 through polymer breakdown and microbial decomposition of organic compounds. Here, we investigated, for the first time, the biogeochemical mechanisms involved in PP-driven OA and the role of plastic as a modifier of the seawater carbonate system. Laboratory microcosm experiments were conducted using naturally aged plastic particles ranging from 2 mm to 2.17 cm, incubated in seawater under different light conditions (irradiated and dark). The experiment consisted of two 7-day phases: (1) an abiotic phase to assess physicochemical effects of plastic degradation; and (2) a biotic phase to evaluate microbial contributions to plastic-induced acidification. Variations in pH, dissolved CO2 concentrations, and aragonite saturation state (Ωarag) were monitored as proxies for acidification. During the abiotic phase, plastic increased dissolved CO2 concentrations, with values three times higher under irradiated conditions. Consequently, pH and Ωarag decreased significantly, reaching terminal values for coral reef development (pH = 7.7 and Ωarag = 2.0). During the biotic phase, no significant changes in acidification proxies were detected, attributed to the low release of dissolved organic carbon from plastic, reinforcing direct CO2 production as the primary mechanism driving observed changes. These results suggest that PP may intensify OA, exposing corals to increased stress and mortality, ultimately leading to losses in reef cover and biodiversity.

 

COMMITTEE MEMBERS:
Presidente - 3257898 - Cybelle Menolli Longhini
Interno - ***.178.178-** - EDSON APARECIDO VIEIRA FILHO - UESC-BA
Externo à Instituição - Fabian Sá - UFES