The detrimental effects of PAHs aquatic ecosystems are well documented. Examples:
Fish - When fish are exposed to PAHs, they exhibit chronic problems, including fin erosion, liver abnormalities, cataracts, skin tumors, and immune system impairments leading to increased susceptibility to disease.
Benthic macroinvertebrates - When benthic macroinvertebrates, insects and other organisms that live at the bottom of rivers and lakes and that make up the base of the aquatic food chain, are exposed to PAHs, they are susceptible to a number of detrimental effects, including inhibited reproduction, delayed emergence, sediment avoidance, and mortality. The most important mechanism by which acute effects occur in benthic invertebrates is a nonspecific narcosis-like mode of action that results in the degradation of cell membranes. Ultraviolet (UV) radiation greatly increases the toxicity of PAHs in a wide variety of aquatic organisms.
The City of Austin has conducted a range of laboratory and field experiments which documented the negative effect that PAHs from coal tar sealants have on benthic invertebrates that live in our streams. This work was a primary support and motivator for the ban of coal tar sealants in Austin