Microcystins in transitional and marine ecosystems: Source categories, distribution patterns, and ecological impacts

Area of Science:

• Environmental Science
• Marine Biology
• Ecotoxicology

Background:

• Microcystins (MCs) are well-known freshwater algal toxins with documented environmental impacts.
• Recent findings indicate the continuous presence of MCs in marine ecosystems, including brackish, estuarine, and coastal waters.
• Existing literature on MCs in marine environments is limited, necessitating a comprehensive review.

Purpose of the Study:

• To elucidate the sources, distribution, and ecological impacts of microcystins (MCs) in marine ecosystems.
• To provide a global overview of MC-producing algae transfer from freshwater to marine environments and secondary outbreaks.
• To identify critical knowledge gaps regarding MCs' fate, behavior, long-term consequences, and impact on marine microbial communities.

Main Methods:

• Comprehensive literature review of existing studies on MCs in marine habitats.
• Analysis of global data on the delivery of MC-producing algae from freshwater to marine ecosystems.
• Examination of MCs' effects across various trophic levels in marine environments.

Main Results:

• MCs are present in diverse marine settings, originating from both freshwater runoff and secondary marine outbreaks.
• Evidence shows MCs impacting various trophic levels within marine ecosystems.
• The review consolidates current knowledge on MC distribution and ecological effects outside of freshwater systems.

Conclusions:

• There is a critical need for a deeper understanding of MCs' fate and environmental behavior in marine settings.
• Long-term consequences and the impact of MCs on marine microbial communities require further investigation.
• Targeted management strategies are essential for safeguarding marine ecosystem health from microcystin contamination.