This is the abstract of a publication made at: 2nd International Conference on Global Food Security
Authors: O. Torrissen*, R.E. Olsen
1Institute of Marine Research, Norway, 2NTNU, Norway
Feeding the increasing population of the world will face severe challenges due to the climatic changes and increased greenhouse gas emissions by increased terrestrial food production. The challenges are further strengthen by availability of land, water and fertilizer resources. Contrary to terrestrial land, the oceans are still not cultivated in any measurable scale. There is a huge potential in increasing the sustainable production of finfish.
Saline water covers approximately 72% of the planet’s surface (~3.6×108 km2), and marine primary production is at the same magnitude as that on land, 50 petagrams (1015) of carbon per year of net primary production (F. P. Chavez, M. Messié, and J. T. Pennington,2011. Annu. Rev. Mar. Sci. 2011. 3:227–60). However, marine food production gives only basis for just over 1% of the average human energy intake (FAO, 2014). Fish and fishery products represent a valuable source of animal protein, and in 2010, fish accounted for 16.7 percent of the global population’s intake of animal protein or 6.5 percent of all protein consumed (FAO, SOFIA 2014: http://www.fao.org/fishery/sofia/en).
The total marine catch of fishes has leveled off at around 80 million tons (live weight) the last years while aquaculture continues to grow and reached nearly 25 million tons in 2012. Mollusks production accounts for 15 million tons, crustacean 4 and finfish 5.5 respectively. Atlantic salmon and rainbow trout are the dominating species farmed in the marine environment, and are probably also the most developed and industrialized aquaculture production. The productions of these two species were in 2013 2.1 and 0.23 million tons respectively (www.FAO.org, FishstatJ, 2015).
The feed ingredients of salmon feeds have changed tremendously over the last 20 years. The amount of plant ingredients has increased from 10% to more than 70%, and salmon feeds without use of fishmeal and oil from forage fisheries are easily produced. Farmed salmon is now at tropic levels similar to domestic animals as pigs and chickens (2-3) compared to tropic level 4-6 for wild salmon.
Salmon is an exceptionally efficient producer of animal proteins and marine fat. This due to several factors:
• Farmed terrestrial animals require housing in area while fish uses volume. Housing areas for salmon is very low.
• Their reproduction capacity is very high. A female salmon produce thousands of eggs, a hen lays hundreds and a pig tenths.
• They are weightless in water and needs only a light skeleton with small extremities. Together with low skin weight this gives a very high edible yield.
• Salmon are poikilothermic, and they don’t need to use energy for maintaining a constant body temperature.
• Salmon store fat in muscle tissue, and little is lost in cutting and trimming the edible meat.
• Fish live in water and can excrete ammonia as such directly to water. They metabolize proteins and N-containing compounds efficiently
The effect these factors are very efficient transfer of protein and energy from feed into edible fish fillet. Salmon has a 1.5 and 2 times as efficient protein and energy retention compared to farm animals as chicken and pigs.
Salmon farming is in a global food security perspective an extremely efficient converter of feed into edible meat. The industrialized production and processing ensure an efficient conversion of byproducts into feed ingredients and food supplements.
The global potential for salmon production is large, and there are a potential of increasing today’s production of 2.1 million tomes by a factor of 10.