Chronic exposure to glyphosate in Florida manatee

Area of Science:

• Environmental Toxicology
• Wildlife Health
• Ecotoxicology

Background:

• Florida manatees rely on freshwater for drinking and warm-water refuges.
• These critical habitats are increasingly exposed to human activities, including the use of glyphosate-based herbicides.

Purpose of the Study:

• To determine glyphosate and aminomethylphosphonic acid (AMPA) concentrations in Florida manatee plasma.
• To assess manatee exposure in warm-water refuges in Crystal River and South Florida.

Main Methods:

• Analyzed glyphosate and AMPA in 105 Florida manatee plasma samples (2009-2019) using HPLC-MS/MS.
• Monitored water bodies in Florida for glyphosate and AMPA using grab samples and MIP-POCIS (2019-2020).

Main Results:

• Glyphosate detected in 55.8% of manatee plasma samples, with concentrations increasing from 2009-2019.
• Glyphosate and AMPA were widespread in water bodies, with higher levels in South Florida, especially during sugarcane harvest.
• Manatees showed chronic exposure to glyphosate and AMPA, potentially impacting their immune and renal systems.

Conclusions:

• Florida manatees experience chronic exposure to glyphosate and AMPA.
• Herbicide exposure may be linked to sugarcane cultivation and aquatic weed control.
• This exposure could exacerbate health issues in manatees, alongside other environmental stressors.