The joint effect of polycyclic aromatic hydrocarbons on fish behavior

Area of Science:

• Environmental Toxicology
• Marine Biology
• Ecotoxicology

Background:

• Polycyclic aromatic hydrocarbons (PAHs) are pervasive organic pollutants in marine ecosystems.
• PAHs pose significant risks to marine organisms, yet their combined effects on fish behavior are poorly understood.
• Understanding joint PAH action is crucial for assessing ecological risks in contaminated waters.

Purpose of the Study:

• To analyze the concentration-response relationships of individual PAHs (fluorene, phenanthrene, pyrene) on gilthead seabream behavior.
• To predict and evaluate the mixture effects of these PAHs on fish behavior using the concentration addition model.
• To assess the accumulation and behavioral impacts of PAHs and their mixtures in fish muscle.

Main Methods:

• Conducted 4-day behavioral tests on juvenile gilthead seabream (Sparus aurata).
• Assessed locomotory and social behaviors in response to individual PAHs and a PAH mixture.
• Applied the concentration addition model to predict mixture toxicity and compared predictions with observed effects.

Main Results:

• Individual PAHs and their mixture accumulated in fish muscle, causing dose-dependent behavioral changes.
• Pyrene (PY) was the most potent PAH affecting swimming and lethargy; fluorene (FE) was the least potent.
• Lethargy was the most sensitive behavioral parameter, while social interaction was the least affected; predicted and observed mixture effects showed good agreement.

Conclusions:

• The concentration addition model accurately predicted the joint behavioral effects of PAH mixtures in gilthead seabream.
• PAH mixtures significantly alter fish behavior, with lethargy and swimming being key indicators of exposure.
• Findings underscore the ecological risks of PAH mixtures to marine fish populations and inform environmental risk assessments.