Physicochemical and microbiological investigation of ballast waters of the ships operating in the Marmara Sea

Abstract

Ballast water, an essential component of global shipping operations, plays a pivotal role in maintaining vessel stability and load distribution. However, its inadvertent discharge can introduce a myriad of physicochemical and microbiological hazards to marine ecosystems, necessitating rigorous investigation. This study presents a comprehensive analysis of ballast waters from ships operating in the ecologically significant Marmara Sea. Different than previous studies, physicochemical parameters, including pH, heavy metal concentrations (Cr, Fe, Co, Ni, Cu, Zn, and As), total organic carbon, turbidity, total nitrogen, and total phosphorus, were extensively assessed. Furthermore, microbial communities were examined through the identification of bacterial, archaeal, and algal taxa using 16S and 18S rRNA gene amplicon sequence data. Particular attention was given to potential pathogens and harmful algal species, employing advanced techniques to ensure accuracy and comprehensiveness. The findings reveal notable variations in the physicochemical profiles of ballast waters, attributed to diverse geographical origins and operational factors. Furthermore, the microbial analysis identifies a diverse array of species, including pathogenic strains and potentially toxin-producing algae, raising concerns about potential ecological and public health implications. These results underscore the urgent need for improved ballast water management strategies and the implementation of effective treatment technologies to mitigate the adverse effects of ballast water discharge in the Marmara Sea. By shedding light on the intricacies of ballast water composition, this study contributes valuable insights toward safeguarding marine biodiversity and human wellbeing in this ecologically sensitive region.