Toxicity of benz(a)anthracene and fluoranthene to marine phytoplankton in culture: Does cell size really matter?

► Polycyclic aromatic hydrocarbons (PAHs) in the marine environment are a hazardous chemical legacy. ► Benz(a)anthracene and fluoranthene are toxic to phytoplankton photosynthesis and growth in culture. ► Acute (photosynthesis) and chronic (population growth) effects have different thresholds. ► Toxicity depends on both the species selected as a model and the compound considered. ► Further study of the size/sensitivity relationship is required to draw more general conclusions.