So Are Those Crop Circles In The Ocean?

No! They’re tuna farms. Or Tuna ranches, as some call them

When travelling the coast highway you can’t miss seeing the large circular pens just offshore. These are tuna farms. These Charlie Tunas spend their entire lives in captivity.

There is a skyrocketing demand for bluefin tuna, the favorite of sushi and sashimi connoisseurs the world over, especially by the Japanese, who consume about 90% of the delicacy.

However, the harvesting of wild blue fin by huge commercial fishing vessels was so rapidly depleting the supply of tuna in their natural habitat that efforts were mounted to have the species added to the list of creatures protected under the Endangered Species Act, an effort vetoed by the Obama Administration five years ago. The administration did back a proposal to ban the international trade of Atlantic blue-fin tuna, a proposal defeated, largely due to opposition by Japan. The Japs send over big factory ships that processed the tuna right then and there. The tuna were still toweling off when they were cleaned and canned, ready to be taken back to Japan. That’s Mexico’s tuna, we’re talking about here.

But pressure mounted, so now they raise fish in captivity in a sustainable, economically feasible manner. Tuna, unlike salmon, has never been successfully farmed because of their migratory nature and slow sexual maturation. The Pacific Bluefin Tuna (PBT) spawns in the waters between southern Japan and the Philippine Islands, then migrates to Baja, (a journey of over 6,000 miles), when they’re between one and two years old. There they begin the maturation process. Once they’ve reached the age of five or six years, they begin migrating back to the other side of the Pacific to reproduce.

Considering their migratory nature, it becomes obvious that wild fish caught in Mexico and detained here in pens, will not reproduce. Therefore, the process of tuna farming has been carefully and scientifically developed.

The farms are owned by companies or conglomerates funded by investors from various countries, primarily by Japan. Maricultura del Norte, for example, operates its enterprise in Puerto Escondido on the south side of Punta Banda. Its founder is a French born Mexican citizen whose investors are Mexican and Japanese. Maricultura obtained a 50 year concession from the Mexican government in the late 1990’s to operate in this specific area. Three of the other leading PBT–producing companies with active ranching operations include investors from Iceland, the United States, Mexico and, of course, Japan.

Maricultura, like the other tuna ranching enterprises, use their own trawlers to net tons of wild tuna as they swim along the coast. Once netted, the catch is very slowly – at less than 2 mph – towed in specially designed enclosures, a mobile habitat in which they are fed a diet of premium sardines three times daily, six days a week. There they gain weight and build up their fat content; the fat content is key. Otoro is the Japanese word for fatty tuna, referring to the fatty belly of the bluefin that is the most sought after prize of sushi connoisseurs. The market price for top quality PBT meat exceeds $50 a pound.

 The end comes when the tuna are lifted out of the pen one-by-one, grasped by the tail and the gills, and clobbered by a bat, killing them instantly. They are then gutted, cleaned and thrown into a tank containing a 32 degree saline solution. The entire process takes less than a minute. No fish is killed until a purchase order has been submitted for them.

Almost all of Maricultura’s product is shipped to Japan. The shipping process itself, from the clobber to the Japanese tuna market takes a little more than four days. But first the fish are carefully placed into plastic-lined boxes with cold gel packs to ensure freshness. The shipping time is perfect for the consumer: Bluefin reaches its peak in flavor and texture four to six days after being plucked from the water.

Environmentalists’ concerns regarding the possible negative impact this farming has on the ocean’s ecosystem have largely been addressed by the industry:

Locally, some expressed concerns that the feeding of the tuna depleted the natural supply of bait, thereby reducing the supply available to wild fish sought by sport fishermen. This fear is allayed by the fact that the farmers supply their own bait because the farmers want to provide their herds with only consistently premium quality nutrition. Also, claims that all that concentrated tuna poop kills the natural supply of bait is negated by the fact that the pens are slowly moved on a consistent basis.

Bluefin ranching is a lucrative enterprise for everyone along the supply chain. Its proponents swear it is an economic success story with no apparent negative effects on the environment, unless the offshore “crop circles” offend one’s sense of aesthetics.