What is the reason for agricultural run-off to kill fish in coastal areas that are potentially hundreds of miles from the fields? a. the fertilizer traps sediments which ultimately clog the gills of the fish. b. the pesticides applied to the crops are selectively toxic to marine fish. c. excess fertilizer can cause dinoflagellate blooms which produce toxins. d. the freshwater from the rivers dilutes the salt water and kills the fish.