Some information on the use of fish oil in aquaculture

An es­ti­mated 450 to 1000 billion small wild ver­te­brate fish are slaugh­tered each year for fish­meal and fish oil. In Jan­uary 2017, I com­piled some in­for­ma­tion on the use of fish oil in aqua­cul­ture to share with some EAs work­ing in an­i­mal ad­vo­cacy. This post is a lightly ed­ited ver­sion of that.

I’m fo­cus­ing on fish oil rather than fish­meal mostly be­cause I’ve spent more time read­ing about fish oil.

The omega-3 fatty acids from fish (EPA and DHA) origi­nate from phy­to­plank­ton (plant-like or­ganisms) rather than fish them­selves.

NOAA says: “Fish oil is a ma­jor nat­u­ral source of the healthy omega-3 fatty acids eicos­apen­taenoic acid (EPA) and do­cosa­hex­aenoic acid (DHA). Th­ese fatty acids are not made by the fish, but be­come con­cen­trated in fish fur­ther up the food chain from the marine phy­to­plank­ton (micro­scopic marine al­gae and microbes) that do syn­the­size them.”

The un­der­stand­ing I have is that nearly all the EPA and DHA available in farmed fish origi­nate from fish oil, mostly de­rived from small wild ver­te­brate fish like an­chovies in Peru, who get this EPA and DHA by eat­ing plank­ton. So, an ob­sta­cle to elimi­nat­ing the fish­meal and fish oil in­dus­try is that, with­out a re­place­ment for the EPA and DHA that comes from fish oil, a pri­mary health benefit of fish would be elimi­nated, and I think con­sumers are un­likely to be happy about this.

The sup­ply for fish oil is con­strained by reg­u­la­tion, but de­mand con­tinues to in­crease.

The In­ter­na­tional Fish­meal and Fish Oil Or­gani­sa­tion (IFFO) says: “This valuable re­source [the small wild fish slaugh­tered for fish­meal and fish oil] is fished un­der care­fully con­trol­led limits set by gov­ern­ment agen­cies based on stock as­sess­ments. Th­ese limits are effec­tively po­liced by gov­ern­ment agen­cies in most of the coun­tries pro­duc­ing fish oil. [...] Pro­duc­tion of fish oil in the fu­ture is not ex­pected to change. More oily fish are ex­pected to be pro­cessed for di­rect hu­man use, thus re­duc­ing that available for fish­meal and fish oil pro­duc­tion. How­ever, grow­ing by-product pro­duc­tion from farmed fish will main­tain the to­tal pro­duc­tion.”

This state­ment seems con­sis­tent with the fol­low­ing graph from IFFO, show­ing that the sup­ply of fish oil (the green line) has shown lit­tle growth since 1968:

Mean­while, this graph from Wor­ldWatch based on FAO data shows a huge in­crease in aqua­cul­ture dur­ing that pe­riod:

Since fish oil is fed to aqua­cul­ture (es­pe­cially car­nivorous fish like salmon), I be­lieve this in­crease in aqua­cul­ture in­di­cates an in­crease in de­mand for fish oil.

Fish oil prices seem to be in­creas­ing due to in­creas­ing de­mand and limited sup­ply.

Here’s an­other graph I found on fish oil prices from 2003 to 2014, show­ing a sub­stan­tial price in­crease af­ter 2011 rel­a­tive to soy­bean oil:

The FAO seems to think high prices are here to stay: “In gen­eral, the fish­meal and oil sec­tor re­mains vuln­er­a­ble due to its limited sup­ply sources, with not much progress be­ing made in this re­gard as de­mand con­tinues to in­crease. Fur­ther­more, ac­cord­ing to IFFO, the global pro­duc­tion of fish­meal is down by about 2.3 mil­lion tonnes com­pared with pro­duc­tion in 2000. In both 2014 and 2015, the El Niño phe­nomenon sig­nifi­cantly af­fected the ac­tual catches, as well as the ex­pec­ta­tion of an­chovy catches in Peru, which is by far the ma­jor fish­meal pro­ducer and has been for many years. With these im­pacts, prices have fluc­tu­ated over the past two years, but in the long-term, prices will not re­vert back to lower lev­els.”

Be­fore the rise of aqua­cul­ture, fish­meal and fish oil were used for low value pur­poses.

Th­ese di­a­grams from IFFO show that be­fore the aqua­cul­ture in­dus­try be­came so large, fish­meal and fish oil were used for low value pur­poses such as pig feed, chicken feed, mar­garine, and in­dus­trial pur­poses.

So even if de­mand from aqua­cul­ture were re­duced or elimi­nated, we could still have com­pa­rable num­bers of feed fish slaugh­tered and sold for these low value pur­poses.

The omega-3 fatty acids (EPA and DHA) in salmon may already be de­clin­ing.

This study of farmed Scot­tish At­lantic salmon already shows a de­cline in EPA and DHA pre­sum­ably be­cause of a de­crease in fish oil in their feed:

Microal­gae and ge­net­i­cally mod­ified plants could serve as al­ter­na­tives.

This pa­per, un­der the sec­tion “Fu­ture sources of EPA and DHA,” con­sid­ers some al­ter­na­tives to fish oil.

Microal­gae oil con­tain­ing EPA and DHA is available to­day and mostly used in hu­man nu­tri­tional sup­ple­ments, but is cur­rently ex­pen­sive to pro­duce.

Ge­net­i­cally mod­ified plants with genes from microal­gae to pro­duce EPA and DHA are cur­rently be­ing in­ves­ti­gated and may be promis­ing as al­ter­na­tives. It seems though that ge­net­i­cally mod­ified feed is not typ­i­cally used in aqua­cul­ture and that in­tro­duc­ing it could cre­ate con­sumer ac­cep­tance and reg­u­la­tory prob­lems.

The com­pany Ver­lasso pre­vi­ously mar­keted salmon fed with ge­net­i­cally mod­ified yeast con­tain­ing omega-3s as sus­tain­able. More re­cently, Ver­lasso has been us­ing al­gae with omega-3s in­stead, per­haps to in­crease con­sumer ac­cep­tance.

Although there are po­ten­tial benefits for an­i­mal welfare, there are some po­ten­tial down­sides. If the aqua­cul­ture in­dus­try finds suit­able al­ter­na­tives to fish oil, this may (a) re­duce a con­straint on aqua­cul­ture pro­duc­tion and (b) per­mit one of the pri­mary health benefits of fish (the EPA and DHA) to per­sist, in­creas­ing con­sumer de­mand for fish.

Some use­ful sources.

  • NOAA has an in­for­ma­tive FAQ on aqua­cul­ture feed.

  • This pre­sen­ta­tion has lots of in­for­ma­tive graphs on pro­duc­tion and de­mand of fish oil and fish­meal.

  • This IFFO pa­per has some use­ful in­for­ma­tion and graphs on pro­duc­tion and de­mand of fish oil and fish­meal.

  • Char­ity En­trepreneur­ship has an in­for­ma­tive re­port on feed fish, mostly fo­cus­ing on fish­meal.