STARTENDER carved a sharp line through the glassy-calm water. Rising and falling with the long swell, Christian, Esther and I cast a foamy trail between Isla de Cíes and the entrance to Ria de Vigo. We turned hard to port, past a harbour marker and approached a raft of floating wooden structures, scattered in a long line about a mile offshore like houses awaiting construction. The square frames on steel pontoons were 20 metres by 20 metres, anchored in position with ropes hanging beneath. Clearly they were shellfish farms of some description, and we pulled up to a fishing boat working alongside one of them to investigate. An orange crane was operating from the top deck, swinging and manoeuvring in an odd rhythm.

A wave is rarely turned down in Spain and the crew returned our gesture with enthusiasm. Marcos, a Clooney look-alike with a better job, invited us aboard and explained the intricacies of the operation with a mix of broken English, Spanish and a smattering of diagrams on the salty windows. We annotated his diagrams, adding figures, and staggered back in Spanish, English and atrocious French. We persevered as both sides of the language rift were clearly enjoying the interaction and trying hard to understand.

Working on the farm.
[ photo - James Frankham ]

Some 40 vessels operated on the floating mussel farms that stretched the length of the bay and another aggregation further up the Atlantic coast. Tiny juvenile Common Sea Mussels Mytilus edulis are scraped off the rocks along the coast with shovels and transported to the floating frames by 20 metre long trawler style work boats. The juvenile mussels are bound around long ropes with a gauze-like fabric, then suspended beneath the frame where they eventually cling and grow. Six months later they are ready for harvest. Marcos explained that over the hundred or so frames, at the two sites, they can recover up to 30 tonnes a day! However he was unwilling to speculate at the annual yield, clarifying that it was “up to God”.

37 trillion kilograms of food (that’s 37 000 000 000 000 kg) is harvested from the world’s oceans every year, a rate that is unsustainable for some species. According to the United Nations Food and Agriculture Organization (FAO), 70% of the fish species that are commercially caught around the world are overexploited, caught to the limit, or recovering from overexploitation. Of course fluctuation in one fish stock affects the landing of other species. Lack of both marine research and international regulation mean that there is very little control of marine resources. In fact, the global catch has doubled since the 1960’s.

Marcos with the seed mussels.
[ photo - James Frankham ]

There are a number of international agreements, which, if abided by, could have a significant and beneficial impact. United Nations Convention on the Law of the Sea (UNCLOS) agreed to extend the responsibility for the marine environment to 200 nautical miles off the coast. Nations that signed, contracted to protect and preserve the marine environment. Some countries, including the United States, have not yet ratified the treaty.

Mariculture (the cultivation of fish and other marine species), such as the mussel farming we saw this morning, could reduce the stress on international fisheries. The global maricultural yield represents nearly 20 percent of world fishery production. However, this solution is not without its problems. Bad practice can lead to enormous environmental destruction. Uprooting mangrove forests in the search for flat tidal land and depleting stocks of krill used as food for the fish can cause more damage than it saves. In areas without tidal flow or currents, bacteria and parasites can bloom quickly within the large, dense populations and often antibiotics are used to control such outbreaks.

On STARSHIP we have visited some interesting projects including tuna farming in Mexico and a fish hatchery in Indonesia. As more is learnt about marine species and new techniques are employed for farming the oceans, mariculture could play an important role in reducing the stress on already depleted stocks. As always, it begins with recognition of the status of the world’s oceans and an understanding of the synergetic mechanisms that determine global fish stocks and distribution. The crew of STARSHIP hopes that nations will begin to cooperate on a far more urgent basis, to deal with some of the most pressing issues of this water planet.

STARSHIP standing by 16, 73

James