Bioindicators of potentially toxic elements in Mangrove ecosystems

Mangrove ecosystems are facing an increased risk of contamination from toxic elements originating from anthropogenic activities. Bioindicating organisms indigenous to an ecosystem can be used to assess the degree of pollution. Microorganisms are the most applied biota in the evaluation of environmental quality using bioindicators, as they can be evaluated via high-throughput metagenomics sequencing technology. The current review provides a comprehensive report of potentially toxic element (PTE) accumulation, associated bioindicators, and analytical approaches for metals and biota in mangrove ecosystems. The review explores microbial interactions with key environmental variables such as pH, redox potential, and salinity. The behaviors of specific metals and related bioindicators in a typical mangrove ecosystem are presented. The review focuses on microbial bioindicators, their abundance and composition, and their analysis via metagenomics. The current review, with emphasis on mangrove ecosystems, provides a foundation for understanding PTE bioindicators and their interactions with the environment. These findings can support future bioindicator-based programs, including ecosystem health assessments and metagenomics-driven monitoring for conservation and restoration.