The necessity for marine agriculture in 2017 and the future

A recent article in Nutraingredients presented the case for omega-3-enhanced plants in farmed fish feed

Photo credit: eutrophication&hypoxia via Visualhunt / CC BY
Photo credit: eutrophication&hypoxia via Visualhunt / CC BY

. To summarise:

  • We will soon see the arrival of Genetically Modified omega-3-enhanced plants.
  • A large-scale Scottish study found omega-3 levels in farmed salmon had halved in five years.
  • The omega-3 food and supplement industry is turning to alternative and sustainable feed sources. Professor Doug Tocher of the Institute of Aquaculture at the Faculty of Natural Sciences at Stirling University is working with UK government-backed Rothamsted Research to develop genetically modified plant-sourced EPA and DHA omega-3s with the camelina plant.
  • Tocher says camelina has been successful at trial level, but regulatory approval and commercial uptake is hindered by strict EU GM laws.
  • Modifying feeding times in a fish’s lifecycle and investigating omega-3 levels in insects were other means that could increase EPA/DHA levels in farmed fish.

Not the full story

This is all very interesting, but it misses some essential facts about the composition of fish-derived oils. Omega-3 oils are a vital part of the story, but they are not the complete story. Plant substitutes, therefore, do not offer a complete solution.

The article notes that EPA-DHA has halved in farmed salmon and that 80% of feed is now coming from land-based sources. This means that farmed salmon reared on this feed will lose out on trace elements, as the content in soils has been diminishing.

This is my main point – fish and sea-food are not just about oils. They are also rich in iodine, selenium, zinc, copper and manganese.

Iodine is essential for many aspects of biology. Without it, thyroxine cannot be made. Iodine deficiency leads to goitre and is devastating in pregnancy, leading to cretinism. Added to the mental retardation, cretinism involves facial deformities due to the lack of full brain development. There are two billion people at risk today, and these all live inland.

Photo credit: jonkriz via Visual hunt / CC BY
Photo credit: jonkriz via Visual hunt / CC BY

When I was involved in iodine deficiency studies with Dr Darwin Karyadi in Indonesia, 1990-93, there were one million severely mentally retarded children in the country and 800,000 cases of cretinism. Some 60% of the school children had palpable goitre. None of these cases were found in the fishing villages.

In Indonesia we recommended growing kelp to provide fertiliser to put the iodine and other trace elements back into the soil. The kelp could also be used to feed livestock and people alike. Using seaweeds as food not only provides iodine and other trace elements but also a small amount of omega-3. They are now doing this in a coastal region of Bali. It is a solution to the problem; and, as it happens, the kelp farmers (they have plots on the sea-bed) are actually making more money than the inland farmers!

Iodine deficiency and other trace element issues

Iodine deficiency has reappeared in UK school girls. This is serious, and is a by-product of the success of intensively reared food production. The problem is consistent with the reduction of sea food intakes.

There are other vital players in this story, apart from iodine. Selenium is used for the seleno-proteins which are a frontline defence for the brain against peroxidative damage. Zinc and Copper are used in the Cupric-Zinc superoxide dismutase, and Manganese in Manganese superoxide dismutase. There is very little vitamin E in the brain, which ensures its protection through these enzymes. Bear in mind the brain uses 20% of the oxygen you breathe but is only 2% of the body weight. Hence it is a massive consumer of oxygen and truly needs protection. The trace elements are critical for this protection, and they co-exist with DHA in all sea foods.

Limitations of the GM solution

The second problem with GM crops producing EPA and DHA is one of composition. It is likely to be mostly triglyceride. Eating fish and seafood, the lipid comes as phospholipid which is the form used by tissues and the brain. Triglyceride is basically a fat store.

The third issue is population growth and the availability of land to grow crops. According to the Foresight report 2011 there was not enough arable land to meet the full requirements of the global population. The population is heading for another billion, and then another. Given that further intensification is needed, you can be sure it will be devoted primarily to serve protein needs. There simply is not enough arable land to accommodate the vast acreage needed to supply omega-3.

People need to do the maths. The idea that we can grow trace-element-deficient crops to fill the gap due to the stagnation of the wild caught marine foods is pie in the sky.

Farming the oceans

Photo via Dana Cristea via VisualHunt
Photo via Dana Cristea via VisualHunt

The solution is marine agriculture, as I recommended to the Japanese Government in 1990. Under the direction of Dr Takahiro Tanaka, they now have a system slung between two islands off the coast of Okayama. With marine pastures and artificial reefs designed for the habitats and behaviour of the seven different target species, they have tripled fish production compared to what is harvested outside the zone. In addition to the fish they are harvesting oysters and mussels.

During our final discussions in 1990, the Minister commented that we now need to “agriculturalise” the oceans. 71% of the planet is water. This resource is currently being exploited by the Neanderthal business of “hunting and gathering”. That idea was abandoned on land when resources began to be questionable some 10,000 years ago.

It is about time the Neanderthals’ sway in the sea was replaced too. We need to acknowledge that we live in the 21st century, with millions malnourished, and mental ill health going through the roof and getting worse. It is time to wake up from our Neanderthal slumber.

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