Guest blog By Eugene Craig Campbell

[On Monday,] Steve and Sherrin visited Korea's first (and so far as we know only) fish farm using a salt water Recycling Aquaculture System (RAS), about a kilometer inland at Yongsu-ri near Gosan. It produces shrimp for the live-fish market. Sea water is recycled through the system continuously to remove waste and oxygenated, not dumping anything directly back to the sea. A small amount of processed waste passes into the city sewer system for further processing, but the solids are being collected to produce fertilizer and most of the soluble nutrients are consumed by microbes in the bio-filters. This type of fish farm is estimated to be ten times more environmentally friendly than the dozens of other fish farms that ring Jeju Island, as well as the thousands more on mainland Korea, Japan and China.

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Sherrin knows much about shrimp, having spent many years fishing them on commercial vessels. She was at the site when the plant was still under construction three years ago, and she knows the Australian Geoff Orpin who imported the technology to Korea. She chatted merrily with Mr. Kim and inquired into such things as biofiltration, waste disposal and feed. This factory was designed to grow fish, which need cleaner water than do shrimp. With some modifications it can be converted for virtually any kind of fish, and the design is destined for export to the Korean mainland. There are many shrimp farms in Korea, but since they depend on the ambient temperature of the water they pump in from the sea (and immediately pump back out) the shrimp only eat, thus grow, for the warmest three months of the year. This facility in Jeju, by maintaining the water indoors, can keep the shrimp warm enough to grow, and be sold, all year long.

Northeast Asia is the most populated region in the world, and the seas around here are very dirty. While Jeju enjoys relatively cleaner water than other shoreline areas in the region, here too there is danger from the type of seasonal dead zones that already plague the southern Japanese island of Kyushu, our close neighbor, as well as nearby areas of China. Nutrient runoffs -- silt and clay down the rivers (Jeju has fairly little of that), agricultural chemicals (but Jeju farmers use a lot of that), human and animal sewage even after it is treated, and fish farm effluent -- all cause algae blooms and disrupts the plankton balance that is characteristic of a healthy ocean ecosystem. Already the world's oceans have seriously degraded from human causes, in some areas including Northeast Asia very severely.
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Already some 30% of the fish people eat worldwide is farmed, and that figure increases each year. Switching to RAS from standard fish farming -- sea water in, water plus fish dung and metabolic waste out
-- will make a major contribution to cleaning up the seas. In the world of aquaculture, RAS is the parallel of organic farming. Standard fish farms are also forced by economic conditions to lace the fish food with antibiotics, a problem that RAS (with its capacity to control water quality control) does not face.
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For 3,300 pages of scientific details on virtually every important issue on ocean health, yet laced with easy-to-understand layman's explanations, visit
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http://www.seafriends.org.nz/.
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At the Seafriends website you will find plain talk, perhaps rather uncomfortable to learn, on what needs to be done to save the sea. It is a formidable task for us and our continuing generations, yet we must take up the yoke and do what we can, because the sea is our biological mother not only from eons past but now as well. It continues to nourish all life on earth with water (rain originates from the sea) and with oxygen from phytoplankton conversion of sunlight (more than half of the planet's oxygen supply is estimated to be coming from the sea, rather than from plants on land as had been previously thought).
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The sea may seem so distant from our daily life, except those few who live nearby or make their living directly from it -- but it is of vital importance for the future of human life and all other life on this planet. Don't mention its recreational value, or its capacity to provide fish in sustainable management of fisheries.
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Scientists understand the ecosystems on land in minute detail but the sea is, literally, a totally different world that runs by radically different biological laws; very, very, very, very little is known about the extraordinarily complex ecosystem of the ocean, wrapped up in the mysterious bio-functions of a "googleplex many" microbes too small to be seen with an optical microscope. We are just barely beginning to learn about the sea, even the geography of the ocean floor.

But we already do know that we dump too much junk, and that a large portion of it ends up in the sea. We know that both seasonal and permanent dead zones have been increasing triplefold (!) about every ten years from nutrition runoff. We know that gigantic areas of both the Pacific and the Atlantic have collected floating junk plastic that either decomposes extremely slowly or maybe never at all. We know the plastic kills various types of sea life. What else do we know? We know that we human beings are responsible to clean up the mess we have made.

How few of us have the capacity to swim around Jeju or paddle the distance in a kayak! Yet each of us can do something. Let's do what we can.

-Eugene Craig Campbell