Final answer:
Without the explicit chapter text, it's impossible to name the two most dangerous places to fish mentioned in Chapter 3; however, places with high industrial pollution or significant ecological damage are commonly known as dangerous for fishing due to health risks and environmental concerns.
Step-by-step explanation:
The question references a chapter that discusses the most dangerous places to fish, but without the specific text or chapter contents, it's not possible to provide the exact locations mentioned. However, environmental biology concerns often cite places with heavy industrial discharge or where overfishing occurs as hazardous to both fish and fishermen. For instance, locations with high levels of mercury (Hg) due to industrial discharge can pose significant health risks, as was the case with the fishing villages mentioned that suffered over 2,000 deaths. Environments affected by bottom trawl fishing, coastal development, shrimp farms, and commercial shipping are known to be particularly detrimental to marine ecosystems, and by extension can be dangerous for fishing due to the ecological damage and potential for contamination.