As presented in the first part of this article, the earth area surface is 71 covered by oceanic water. The water is mainly being used for navigation, transport and other economic sporting activities.
Can humanity consider using the 71 per cent fraction of the earth occupied by the ocean for farming activities? If more lands are cleared, what is the environmental implication of bringing more land into cultivation? Will it increase the greenhouse emission? These are questions and challenges attracting the attention of the innovators and researchers. One of the identifiable solutions to these challenges is “Ocean farming”.
Ocean farming involves growing of food in the ocean as one may discerningly observe that sea vegetable exit flourishing within and under the ocean. Are these vegetable edible? Imagine crops growing in the ocean without fertilizer application, no air, no soil, no freshwater, only seawater and sunlight.
Ocean farming does not practically require weeding, tillage practices and protection of crops against pests and diseases thereby saving costs commonly incurred from such operations.
Ocean farming is “zero-input food production” — it requires no additional freshwater, fertilizer, pesticides, feed or soil to grow. As the price of fertilizer, herbicide, insecticide, water, and feed goes up, zero-input farming will naturally be the most affordable food on the planet.
Plants in the ocean receive nutrients directly from sunlight and beneath the sea. Such nutrients help the plant to grow healthy and super-fast. Plant in the ocean can grow 2 – 2.5 cm a day as stated by an expert of ocean farming. Some of these inputs are hugely energy-intensive and huge climate risks to both freshwater and soil. Ocean farming can be so exciting in addition to its profitability compared to land farming.
The technique of ocean farming or “3D ocean farming” consists of horizontal ropes on the water’s surface, anchored to hurricane-proof floats that connect to lines underwater supporting seaweed crops and interspersed with hanging net enclosures to grow scallops and mussels.
Clam and oyster cages, also connected to the surface ropes, sit on the seafloor. The major crop in ocean farming is seaweed, which is known to improve the marine environment by absorbing dissolved nitrogen and phosphorus.
These are two pollutants that end up in the ocean through agricultural runoff, and carbon dioxide, which drives ocean acidification and global warming. Oyster, another major sea vegetable is also another good nitrogen remover from water.
Seaweed is a highly nutritious addition to human diets and contains protein, vitamin C and calcium. Seaweeds contain more vitamin C than orange juice, more calcium than milk, and more protein than soybeans, are the major feeds of fish, which made them highly nutritious.
“By eating the plants fish eat, we get the same benefits while reducing pressure on fish stocks. So it’s time that we eat like fish” as posited by an ocean farmer. In addition, seaweed can be used as a potent soil fertilizer and animal feed.
On the environmental implication of ocean farming, it is not only environmentally friendly but actually revitalizes degraded or dying ecosystems by creating seaweed groves that become nurseries and sanctuaries for many marine species.
The kelp recaptures some of the nitrogen and phosphorus released from wastes that escape from the aquaculture pens, helping make salmon farming — whose high concentration of fish produce large amounts of faecal material — measurably cleaner.
It’s a pro-active approach to conservation, which goes beyond the growing movement to create no-fishing reserves. Therefore, in this era of climate change, serious consideration should be accorded to the preservation of the world’s oceans so that they continue to serve humanity without becoming destructive.
Consequently, there should be a strategy of restoration of oceans within the conservation efforts of environmentalists. Questions asked by enthusiastic ocean farmer capture the environmental friendliness of the ocean farming “It’s not just about: How can we save the oceans? How can we protect sea animals?
It is also about how can the oceans save us? How can it provide food, jobs, safety, and a sustainable way of life? I’m convinced the answer is ocean conservation with symbiotic green farms.,” which is successfully being provided by Ocean farming.
The profitability of ocean farming is the result of the prolific nature of ocean greens such as kelps, which are not only small boutique crops but can grow incredible amounts of food in small areas. Kelps can produce 25 tons of greens and 250,000 shellfish per acre in five months.
Additionally, Seaweeds could be a powerful source of zero-input biofuel. Feasibility studies from a research station indicated that 2,000 gallons of ethanol per acre could be produced from seaweeds — that’s 30 times higher yield than soybeans and five times more than corn can produce.
The kelp will grow eight to twelve feet in a five-month period. And the whole food column is nourishing. The oysters, mussels, and scallops provide low-fat protein and all sorts of important vitamins: selenium, zinc, magnesium, iron, B vitamins, and omega-3s. The sea vegetables are analyzed — different forms of algae like kelp — and they create lots of vitamins and minerals and nine different amino acids, plus omega-3s.
Ocean farming is the most efficient way of growing food, environmentally sustainable way possible — vertically. And it grows quickly. Can Nigeria farmers start to think of ocean farming?
Well, in Nigeria, we are yet to cultivate fifty per cent of our arable land, and thus, ocean farming is more theoretical than practical, however, this option is still available for our future needs.
Yes, let us develop more than 40% of arable land through infrastructural development and adoptions of mechanize farming.
Professor Othman is the Executive Director of National Agricultural Extension and Research Liaison Services (NAERLS), ABU Zaria.