Aquaculture, as a rapidly growing food industry, faces significant challenges related to the health and sustainability of aquatic ecosystems. The indiscriminate use of antibiotics to prevent and treat diseases in fish has generated increasing concern due to its impact on the environment and public health.
A study published by researchers from the South China Sea Fisheries Research Institute, the Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, the Southern Marine Science and Engineering Guangdong Laboratory, and the Guangdong Provincial Key Laboratory of Fishery Ecology and Environment in the Journal of Hazardous Materials investigated the main source of antibiotics in tilapia farming systems, as well as the role of suspended solids in the distribution of these contaminants. By analyzing antibiotic levels in different components of the aquaculture system, including water, sediments, feed, and tilapia tissues, the aim is to understand the mechanisms of contamination and bioaccumulation.
The Antibiotic Crisis
The indiscriminate use of antibiotics in various sectors, including human and animal medicine, has generated a serious global public health crisis. These compounds, once considered miraculous, now represent a growing threat due to their persistence in the environment and the proliferation of resistant bacteria.
Aquaculture, a rapidly growing industry aimed at meeting the increasing demand for animal protein, is no exception. The excessive use of antibiotics in this sector has significantly contributed to the contamination of aquatic ecosystems and the accumulation of residues in seafood products.
Antibiotics in Aquaculture
Recent studies have revealed the worrying presence of antibiotic residues in water, sediments, and aquatic organisms in farming areas. The intensity of contamination varies according to factors such as stocking density, frequency of medication, administered dose, and environmental conditions.
Tilapia, a widely consumed farmed fish, has emerged as a focal point. Although it is an important source of protein, its intensive production can be compromised by antibiotic contamination. Until now, details about the sources, fate, and key factors influencing antibiotic contamination in tilapia aquaculture were unknown.
Accumulation of Antibiotics in Tilapia Farms
The study was conducted in a marine water tilapia farm located in Maoming city, Guangdong province, known as the “Tilapia Capital of China.”
The research results reveal a worrying pattern: antibiotic concentrations in pond water and sediments gradually increase during the cultivation cycle. This phenomenon is closely linked to environmental factors such as suspended solids and chemical oxygen demand, which facilitate the dispersion of these compounds.
A crucial finding is the identification of the main source of antibiotics in the farming system: the water used to supply the farms. This underscores the importance of properly managing and treating water sources to reduce the entry of antibiotics into aquatic ecosystems.
Bioaccumulation and Health Risks
Another relevant aspect is the bioaccumulation of antibiotics in tilapia tissues. Although levels vary according to the type of antibiotic, the study highlights the high bioaccumulation capacity of sulfadimethoxine. This phenomenon raises serious concerns about food safety and the potential transfer of antibiotic residues to consumers.
Environmental Impact and Need for Change
Statistical analyses identified the main relationships between environmental factors and the presence of antibiotics. These findings are fundamental to understanding the mechanisms of distribution and environmental fate of these compounds.
There is an evident need to adopt antibiotic-free aquaculture practices to minimize environmental impact and protect public health. Additionally, effective management strategies are required to reduce antibiotic contamination in aquatic ecosystems.
Conclusions
“These results highlighted the complex relationship between environmental factors and antibiotic contamination, and underscored the need to adopt a multifaceted approach to mitigate associated risks,” the scientists conclude.
This study provides valuable information for the development of policies and management measures aimed at controlling antibiotic contamination in tilapia aquaculture. It is essential to continue researching the long-term effects of these compounds on aquatic ecosystems and human health.
The transition to sustainable aquaculture involves a holistic approach that includes disease prevention, responsible use of medications, and the development of effective alternatives to antibiotics.
The study was funded by the National Key R&D Program of China, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Natural Science Foundation of Guangdong Province, Central Public-interest Scientific Institution Basal Research Fund, CAFS, the fund for CARS-48, and the Rural Science and Technology Commissioner Program of Guangdong Province 2021.
Contact
Yucheng Cao
South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences
Guangzhou 510300, China.
Email: cyc_715@163.com
Reference
Su, H., Duan, S., Hu, X., Xu, W., Xu, Y., Wen, G., & Cao, Y. (2024). Spatiotemporal dynamics, bioaccumulation, and critical influencing factors of antibiotics in tilapia aquaculture: A study on source identification and environmental fate within typical farming systems. Journal of Hazardous Materials, 477, 135328. https://doi.org/10.1016/j.jhazmat.2024.135328
