杏吧原创

You have pioneered the idea of farming within the ocean鈥檚 water column. What inspired you?

I鈥檓 not a scientist, I鈥檓 not an engineer, I鈥檓 not an oceanographer 鈥� I鈥檓 just a regular guy who grew up in a small fishing village and dropped out of high school. After more than 30 years travelling the world catching all kinds of fish, I couldn鈥檛 deny the damage commercial fishing causes. I decided to learn to work with the ocean, not against it.

What did you do in response to seeing this damage from commercial fishing?

First, I went from ocean fishing to ocean farming: for seven years or so, I grew oysters on my coastal farm. But when the storm surges of hurricanes Sandy and Irene hit, my farms were completely wiped out. I realised I had to rethink my farm design. That鈥檚 when I developed the model, which involves more flexible infrastructure that鈥檚 better able to withstand storms and less expensive to replace if it does get ruined.

What is 3D ocean farming, exactly?

It鈥檚 farming that utilises the whole coastal water column, from top to bottom, so a lot is produced in a relatively small area. Thimble Island Ocean Farm, my original farm in Connecticut, goes down to 6 metres, but the 3D ocean farming model can work in anything from 3 to about 25 metres of water. Seaweed, particularly sugar kelp, and mussels are grown on ropes hanging in the water above oyster and clam cages (see diagram). One acre of sea can produce between 10 and 30 tonnes of sea vegetables and 250,000 shellfish every five months. We catch a few fish, too. Nutritionally, ocean plants like seaweeds are just as healthy and often healthier than land-grown foods. And bivalves are a source of lean protein that grows quickly.

What is so good about farming in water?

First off, you don鈥檛 have to fight gravity, so all you need is cheap but strong underwater infrastructure. An ocean farm is easily tended from a boat and doesn鈥檛 require the expensive inputs needed by most aquaculture and land-based farms. Crucially, we don鈥檛 have to feed or water 鈥渃rops鈥� once we seed them. Being in coastal waters means they often benefit from the nutrient-rich run-off from fertilised land farms. And the farms are visually low impact, with just some buoys visible above the water.

You call your farms 鈥渞estorative鈥�. Why?

Kelp is among the world鈥檚 fastest growing plants, so it could absorb large quantities of carbon from the atmosphere, making it the perfect crop for helping to mitigate climate change. And each oyster can filter 50 gallons of water a day. Many aquatic ecosystems suffer from excessive nitrogen, mostly from fertiliser from industrial farms. Shellfish pull that nitrogen out of the water. And we鈥檙e not catching many fish, so vertical farms become artificial reefs, havens for hundreds of species. Finally, the farms are strong yet flexible, helping to protect the coastline from storm surges.

Is your 3D system catching on?

I created the non-profit organisation GreenWave a year-and-a-half ago. Since then, we have helped 12 farmers adopt the model in the north-east US. These are not franchises; we simply help them set up and offer ongoing support. We have another 25 farms in the pipeline, and in the next five years we will have helped create as many as 100 farms in the region. They are cheap to set up, and that鈥檚 the key to replication while everything else in the world is getting more expensive. Right now, we have interest in every coastal state and 20 countries.

You paint a very positive picture. What problems does ocean farming face?

Oceans are a commons: anyone can boat and swim in them, and people can dive around our kelp forests, which are also a great place for recreational fishing because they鈥檙e such rich ecosystems. But you can imagine a scenario in which there are many poorly placed farms 鈥� it could become a battle for sea space. We鈥檝e already experienced the not-in-my-back-yard effect, a little pushback from locals wary of coastal farms.

But really the downside is climate change, and how to stay ahead of the curve. Will I be able to grow sugar kelp 10 years from now? Warming seas have already wiped out natural kelp forests in some tropical parts of the world, so climate is a real threat. If we don鈥檛 do the science now to determine which species will survive in evolving climatic conditions, things will change, we won鈥檛 know how to adapt and everything I鈥檝e done could be for naught.

And then there鈥檚 another question: how will we get American consumers to embrace kelp?

Do you think it will be possible to make eating kelp mainstream?

Such things take time, but we can鈥檛 continue eating fish 鈥� our last wild, staple food 鈥� at its current rate. Climate change is altering ocean habitats by warming seawater, and the increased carbon in the oceans is making the water more acidic, so many fish stocks are falling. Couple that with overfishing and we could be looking at entire populations being wiped out. As Jacques Cousteau said, 鈥淲e must plant the sea鈥� using the sea as farmers instead of hunters. That is what civilisation is all about 鈥� farming replacing hunting.鈥�

鈥淥ne acre can yield 30 tonnes of vegetables and 250,000 shellfish in five months鈥�

My goal is to rearrange the seafood plate, moving sea vegetables and bivalves to the centre and fish to the edge as something to be savoured occasionally. Fish should be a treat. There are thousands of edible ocean plants and hundreds of shellfish species to explore.

What will push people in the right direction?

This year, GreenWave won the . At the ceremony in Copenhagen, I got to eat incredible food prepared by Ren茅 Redzepi, a chef with two Michelin stars. The 20-course meal was almost completely made up of shellfish and seaweeds. It鈥檚 up to chefs to make ocean-farmed foods delicious, that鈥檚 what will drive people鈥檚 dietary acceptance of sea plants and animals. We do climate farming; they need to do climate cuisine. Perhaps we can make kelp the new kale.

This article appeared in print under the headline 鈥淔ish extinctions? Not if I can kelp it鈥�