Aquaponics - ecological rearing of fish and cultivating plants

Torstai 7.6.2018 klo 14.49 - Mikko Nikinmaa

There are several problems with food production. Classical agriculture inevitably leads to eutrophication of nearby waters. Meat production usually has a big carbon footprint. Transport of farming products causes carbon dioxide emissions. The mineral sources of the main fertilizer, phosphorous, are becoling exhausted. Transfer from meat production using homeotherms to aquaculture often causes eutrophication. As one solution to meat production growing insects for food has recently become fashionable. However, a major problem for large-scale utilization of insects as food is the mental aversion of consumers in the western world.

Similar problems are not associated with eating fish. Since similar amount of energy is needed for growing a kilogram of fish and insect flesh, utilizing fish as the source of animal protein is as sustainable as the use of insects. Thus, if one can grow fish so that the negative side effects are diminished, aquaculture can be quite sustainable. Aquaponics offers such a solution: recently one has begun cultivating plants without soil. If one combines this alternative with growing fish, the nutrients produced by fish are used to facilitate the growth of plants. In principle a fish restaurant can grow both fish and vegetables needed in the same building which houses the restaurant.  Such solution would solve all the problems with meat production, including the need for food transport. The principles of aquaponics have recently been reviewed by Palm et al. (Aquacult Int (2018) 26:813–842)

Kommentoi kirjoitusta. Avainsanat: nutrients, aquaculture, food production

Environmentally friendly diet

Lauantai 3.2.2018 klo 18.04 - Mikko Nikinmaa

When thinking about environmentally friendly dietSirkka.jpg, the need to replace the meat of endothermic animals, cattle, swine, sheep and chicken, by other alternatives is invariably mentioned. This is mainly because the amount of energy (feed) needed to produce a kilogram of meat is high, meaning that large land areas need to be used for animal herding. Also, the need for water is high. As a recent alternative, insect eating has been advocated. The use of ectothermic animals requires only about 1/10 of the energy (and thus feed) in comparison to cattle meat. However, although insect-eating is quite common in some areas, in our society a lot of people have emotional objections to eating insects. Further, the behaviour of chitin - the exoskeleton of insects - in our gut is not really clear yet. Thus, in western societies it is easier to find other sources of ectothermic meat than start using large amounts of insect flesh (although I have no doubt that the use of insects as food will increase in future). Luckily we have already traditionally used the flesh of ectotherms, mainly fish (but also shrimps, mussels, crabs etc.). Increasing fish consumption is just as environmentally friendly as insect eating, provided that the fish are produced in aquaculture and not a result of overfishing. My advocating aquaculture may seem surprising, as aquaculture is thought of causing a large amount of environmental problems. However, this happens with traditional aquaculture, whe fish are cultivated in natural waters, where their feed and faeces eutrophy water, and the use of medicines and parasitecides cause additional problems. Recent advances enable the use of recirculated water, so that future aquaculture can produce fish in the middle of towns, where they are needed. This also removes the need for long-distance transport, which is an environmental problem. Innovative thinking produces innovative solutions to decrease the environmental impacts of food production.

Kommentoi kirjoitusta. Avainsanat: insect eating, fish, aquaculture, meat diet

Kelps - combatting climate change and a source of food

Perjantai 29.12.2017 klo 19.29 - Mikko Nikinmaa

An important contributor to the climate change is that photosynthesis in the oceans has decreased. Thus, any way of increasing it would be beneficial for combatting carbon dioxide accumulation. One way of doing this would be to cultivate kelp. It could be eaten as part of sallads, as binding the rice in sushi meals etc. The growing kelp would convert carbon dioxide to oxygen. Simultaneously the kelp fields would harbour a rich invertebrate fauna. I have yet not come across any negative sides in advocating kelp farming to combat climate change.

Kommentoi kirjoitusta. Avainsanat: climate change, aquaculture, carbon dioxide