Modern fishing practices threaten biodiversity mainly through the_______. A. chemical poisoning of the water B. accidental capture of unwanted species C. removal of community food supplies D. physical destruction of marine habitats
For this item, I would go with letter "D. physical destruction of marine habitats". Many of the modern ways of fishing poses an irreversible destruction to marine habitats. These practices include trawling, lining methods, purse seining, etc.
