Warming-induced microplastic accumulation and physiological toxicity in fiddler crabs

Area of Science:

• Environmental toxicology
• Marine biology
• Crustacean physiology

Background:

• Organisms face simultaneous environmental stressors like microplastic (MP) pollution and climate change.
• Understanding combined stressor impacts is crucial for ecological risk assessment.

Purpose of the Study:

• To investigate the combined effects of microplastic exposure and elevated temperatures on the fiddler crab Minuca rapax.
• To assess physiological responses, antioxidant enzyme activities, and lipid peroxidation under varying microplastic and temperature conditions.

Main Methods:

• Fiddler crabs were exposed to polyethylene microspheres (0 and 2 mg L⁻¹) at 24, 27, and 30°C.
• Physiological parameters measured included oxygen consumption, antioxidant enzyme activities (SOD, CAT, GPX), and lipid peroxidation (LPO).
• Microplastic bioaccumulation was quantified in gills, digestive tract, and muscles.

Main Results:

• Microplastic bioaccumulation was highest in gills, decreasing at 30°C.
• Elevated temperatures (30°C) increased oxygen consumption in microplastic-exposed crabs.
• Antioxidant enzyme activities (SOD, GPx) increased at 27°C, while catalase activity and LPO decreased at 30°C in microplastic-exposed crabs.

Conclusions:

• Combined microplastic exposure and temperature stress exacerbate physiological toxicity in Minuca rapax.
• Temperature influences microplastic bioaccumulation and physiological responses.
• Assessing multiple stressors is vital for understanding microplastic contamination impacts on marine organisms.