Banca de QUALIFICAÇÃO: LARISSA NAYARA LIMA SILVA

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
DISCENTE : LARISSA NAYARA LIMA SILVA
DATA : 29/07/2024
HORA: 14:00
LOCAL: CELBE e de forma remota
TÍTULO:

Unveiling the Effects of Mercury in Fish Farms and on Fish Behavior

PALAVRAS-CHAVES:

Aquatic Contamination

Bioaccumulation

Ecotoxicology

Environmental Monitoring

Food Safety.

PÁGINAS: 90
GRANDE ÁREA: Outra
ÁREA: Ciências Ambientais
RESUMO:

Mercury contamination in fish farms is a growing concern due to its high toxicity and the risks it poses to human health and ecosystem integrity. This thesis is divided into three articles aiming to investigate the presence and effects of mercury in fish farms, both from a global and regional perspective, and to analyze the behavioral responses of fish exposed to different levels of mercury contamination. In the first article, we conducted a systematic review and meta-analysis of mercury concentrations in fish from fish farms worldwide. Searches were conducted in the journals ScienceDirect, SciElo, LILACS, PubMed, and Scopus, resulting in 398 articles, of which 22 were accepted for data extraction. Statistical analysis revealed regional differences in mercury contamination in farmed fish, with Africa standing out due to high concentrations associated with illegal fish farming practices. The fish species Hoplias lacerdae, Oreochromis niloticus, and Pseudoplatystoma corruscans exhibited the highest mercury concentrations (1300±0 µg/kg, 912.72±1595.17 µg/kg, and 630±0 µg/kg, respectively), suggesting a strong influence of dietary habits and local environmental conditions. Identifying high mercury concentrations in specific fish species underscores the influence of regional and environmental factors, highlighting the need for local and global approaches to monitoring and mitigating risks. In the second article, mercury concentrations were analyzed in 12 fish farms in the State of Mato Grosso, Brazil. Samples of sediments, soils, and vegetation from fish tanks and adjacent areas (approximately 15 meters from the tanks) were collected. Additionally, muscle, brain, liver, and fin tissues from the fish were sampled. The results showed that mercury concentrations were below the limits established by Brazilian legislation, but we emphasize the importance of continuous monitoring due to the persistent toxicity of mercury and its potential long-term impact on human and environmental health. The third article presents a behavioral experiment to evaluate the responses of fish exposed to different mercury concentrations in controlled environments. Using multi-compartmental systems with linear and random choices, where three compartments served as control, three compartments had a low concentration of 0.5 mg/kg (maximum limit accepted by Resolution RDC No. 42/2013 of the Brazilian Health Regulatory Agency (ANVISA) for fish consumption), three compartments had a medium concentration of 2.5 mg/kg (five times the ANVISA limit), and three compartments had a high concentration of 5 mg/kg (ten times the ANVISA limit). We observed that fish showed a preference for compartments with lower mercury concentrations (control and ANVISA-established concentration). This avoidance behavior suggests an ability of fish to detect and avoid more contaminated areas, which has important implications for understanding the ecological impacts of mercury contamination and for managing fish farms. Therefore, the implementation of effective monitoring and regulatory measures is crucial to mitigate the risks associated with mercury contamination and to ensure food safety and environmental preservation.

MEMBROS DA BANCA:
Presidente - 83200001 - AUREA REGINA ALVES IGNACIO
Interno - 80970002 - DIONEI JOSE DA SILVA
Interno - 82438001 - SANDRO BENEDITO SGUAREZI
Externa à Instituição - SIMONE CARDOSO - UFJF