Traditional blue-fin tuna fishing, Spain. An Atlantic blue-fin tuna fish being caught using a traditional fishing method known as almadraba. In spring, fishermen set nets into the waters of the Mediterranean to capture tuna that are migrating to warmer waters. The nets form a maze which lead the fish into a central pool. A floor net is then raised allowing the fishermen to capture the fish. Almadraba is thought to have first been used by the Phoenicians 3,000 years ago. The fishermen adhere to strict quotas and only select the largest specimens for capture.