Contrast antibiotic activities from muddy and sandy coasts and their potential controls

Area of Science:

• Environmental Science
• Marine Biology
• Ecotoxicology

Background:

• Antibiotic pollution poses ecological risks to global coastlines, particularly muddy and sandy environments.
• Sediment composition critically influences the transport and fate of antibiotics in coastal zones.

Purpose of the Study:

• To investigate how sediment properties differentiate antibiotic pollution patterns and regulatory mechanisms in muddy versus sandy coastlines.
• To compare antibiotic concentrations, proportions, and sources between mangrove (muddy) and sandy beach ecosystems.

Main Methods:

• Comparative analysis of antibiotic pollution in porewater and sediment from contrasting coastal types.
• Source apportionment of antibiotics in mangrove and sandy beach environments.
• Assessment of sediment properties' role in antibiotic distribution and ecological risk.

Main Results:

• Muddy coast porewater exhibited significantly higher antibiotic concentrations (18.4-182 ng/L) than sandy beaches (13.3-30.4 ng/L).
• Sandy sediments contained higher proportions of tetracyclines compared to muddy sediments.
• Antibiotics in mangroves originated mainly from sewage, while sandy beaches received them from non-point sources via runoff and tides.

Conclusions:

• Sediment characteristics fundamentally govern the spatial distribution and ecological risks of coastal antibiotic pollution.
• Divergent retention capacities of muddy and sandy coasts lead to distinct ecological risk patterns.
• Effective management requires source control for muddy coasts and pathway interception for sandy coasts.