Researchers follow the movements of a pair of female great whites . Mary and Elizabeth were tagged off of ' Cape Ann in August . These huge sharks ' irregular behavior comes on the heels of the catch of a rare goblin shark in Florida in May and the closing of an Alabama beach because of a `` swarm '' of sharks this month . A researcher says the sharks ' numbers are surprising for this time of year .
Researchers follow the movements of a pair of female great whites . Mary and Elizabeth were tagged off of ' Cape Ann in August . A researcher says the sharks ' numbers are surprising for this time of year .