On-board Diary: Twenty-Eight Fishing Boats the Balearic Sea and The Giant Bluefin Tuna

Author: Keith Ellenbogen
Date: June 3, 2008



With the break of light, blue skies, calm seas and a watchful perched on the boats A-Frame, we continued to follow the two fishing vessels into the Balearic Sea. At 10 am this morning with no land in sight, 30 miles South of Formentera Island, I could hardly believe my eyes. As I gazed at the horizon all I saw was fishing boat after fishing boat. It was an orgy of tuna fishing boats in a mad rush to catch the bluefin tuna in the annual migration to spawn in the Mediterranean.

By the end of day we counted at least twenty-eight related bluefin tuna fishing boats in a 2 mile radius that included: purseiners, longliners, general fishing boats, tug-boats, Gardia Civil Patrol boat, and our boat, the Oceana Marviva with an international crew of concerned citizens for the marine environment. In addition to the larger fishing boats we also observed dozens of dingies, small auxiliary boats, and scuba divers.

As we arrived on scene, one of the French fishing boats (Marcal MA 146961) — I assume feeling the pressure of reaching and exceeding the fishing quota — vented his frustration by trying to intimidate us to leave. After blowing off some steam they moved onward.

Purseiners Fishing Technique

Throughout the day we were able to document the process of purseiner fishing boats catching the Atlantic bluefin tuna and transferring them to tuna cages. This is a fishing operation in which the bluefin tuna concealed beneath the surface trapped, alive and in cages. The technique is for the purseiner fishing boats to locate schools of bluefin tuna. When the time is right they strike, by accelerating the boat in a large circle releasing the net to catch the fish. Once the fish are caught in the net they are transferred underwater to the cage — via a door that connects or joins the two nets. Using divers and lifting up the net the tuna are corralled into the cage. Once all the fish are transferred, the cage is hauled to the nearest fish farm using a tug boat.

During the day we observed three purseiners transferring bluefin tuna to underwater cages. The process takes about 2-3 hours from start to finish. In one instance the purseiner fishing boat was not fast enough or missed a school of bluefin tuna. In this instance, instead of transferring the fish to a cage they hauled (using a crane) the struggling tuna out of water and into the boat where it was killed.

Throughout the night we remain at this location —in the center of the fishing fleet — to continue to monitor activities tomorrow.