 Scientists identified the genetic mutation that conferred the resistance, and found that the mutated form was present in 99 percent of the tomcods in the river, compared to fewer than 10 percent of the tomcods from other waters.This species can reach a length of .In the 2016 movie "Saltwater" (aka "Atomic Shark"), the San Diego lifeguard investigating numerous shark attacks suggests that there's an "environmental disaster" underway.