U.S. Customs and Border Protection said Friday that authorities seized 708 pounds of marijuana stowed under the fish.
An officer at the Otay Mesa border crossing ordered the truck driver aside Thursday night to put the cargo under X-rays. Authorities said they found 29 wrapped packages of marijuana hidden beneath the fish and a layer of ice.
The driver was a 34-year-old man from Ensenada, Mexico, whose name was not released. He was booked into a downtown San Diego jail for investigation of drug smuggling.