Highlights
- Reviewed 41 relevant chemicals from ballast water and their role in ocean acidification.
- Quantified pH and carbonate ions change in seawater by DBPs using PyCO2SYS.
- Presented the risk assessment and implications of DBPs on the marine environment.
- Presented chemical reactions of discharged DBPs contributing to OA.
- Identified regulatory gap insights and DBPs acidifying effects in the ocean.
Abstract
The world’s blue economy is closely tied to maritime trade, but ballast water from ships often carries harmful aquatic organisms and pathogens, which disrupt the marine environment. To address this, the International Maritime Organization (IMO) mandated ballast water treatment to eradicate these invasive species. However, the treatment processes inherently generate numerous Disinfection by-Products (DBPs). The discharge of these DBPs exacerbates ocean acidification through various acid- and CO2-releasing reactions. The IMO’s Ballast Water Working Group has listed 41 high-priority DBPs for risk assessment due to their toxicity and prevalence in treated ballast water. This review quantitatively evaluates changes in pH and carbonate ions in seawater using the PyCO2SYS software package. Results reveal that DBPs can reduce ocean pH by ∼0.057 units and carbonate ion concentrations by 24.06 μmol kg−1 during a single discharge of 1 m3 treated water. In addition, this review outlines the challenges and research gaps for marine ecosystems sustainability.
Prabhakaran N., Gupta G. V. M. & Kumar B. S. K., 2025. A critical review on ocean acidification driven by disinfection by-products discharge from ships’ ballast water management systems: impacts on carbon chemistry. Marine Pollution Bulletin 217: 118029. doi: 10.1016/j.marpolbul.2025.118029. Article.
