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Antarctic Krill [Euphausia superba, Dana] - A different class of feed ingredient - Heavy Metals’ case

Tuesday, June 24, 2003

Prepared for Aquafeed.com by: Dimitri Sclabos K and Raul Toro

Dimitri Sclabos Katevas is an experienced fisheries specialist, offering consulting and brokerage services for krill and other fisheries technology, marketing and product development worldwide.
He may be contacted at:
E-mail:
dimitri@sclabos.com; Phone: (+56 2) 273 4966; Fax: (+56 2) 273 0395.
Raul Toro: E-mail:
raultoro@yahoo.com; Phone: (+56 2) 854 6442


The new EU import restriction [Directive 2002/32/EC of the European Parliament and of the Council of May 7th 2002] related to undesirable substances in animal feeds is gaining ground. A 500ppm Fluorine max level is being imposed on feeding stuffs of animal origin intended for animal feed from August 1st 2003 onwards, which eventually will stop the usage of crustacean [red] meals in aquafeeds.

This new directive sets the maximum undesirable substance content for 21 different materials, such as heavy metals [arsenic, lead, fluorine, mercury and cadmium], dioxins, nitrites and other substances.

Some of these materials are found in marine origin species, the ones that accumulate such substances in their bones, skin, muscles and organs. Such undesirable substances come from natural origin and/or human-made contamination mainly through wastewater and air pollution.

As Krill meal is also affected, the EU’s Directive shows the limited scientific background used to set such import restrictions.

Krill " Pure and Uncontaminated
South Antarctic Krill [Euphausia superba, Dana] is a small crustacean that only lives in open South Antarctic Seas. This meal is therefore produced from a pure and uncontaminated specie.

Antarctic Krill Meal has been used for many years in aquaculture feeds at an inclusion rate found in the vicinity of 4% depending on each species. It is used as a protein, energy and natural pigment carotene source. It also provides growth promoting factors through krill’s properties found through krill’s special amino acids profile and its feeding stimulant effect.

On my previous report “First Report on The Fluorine in the Antarctic Krill meal” I gave the latest Fluorine content information in krill meals based on updated [2003] data received from the South Antarctic krill Fishing grounds. It shows that krill meal have indeed a high Fluorine content though found in a natural organic form. Animals that fed from krill do not incorporate such fluorine in their flesh, rather in their skin, bones and scales. Accordingly, our suggestion was to raise the EU Directive 2002/32/EC level from its proposed 500ppm to a more realistic level close to 2000ppm [dry basis] for krill meals used as a feed ingredient for aquaculture species.

Besides krill meal’s fluorine attributes, preventing its importation will also hurt other very sensible area required by aqua-feed manufacturers: the need for low heavy metal content feed ingredients.

Based on the work done by myself and associate researcher, Mr. Raul Toro, South Antarctic Krill Meal shows a remarkably low content of undesirable substances such as heavy metals and dioxins, closely related to the unpolluted waters where it is captured and processed.

The South Antarctic krill fishing grounds has unique attributes. It has its own natural barriers such as special sea current activity, circumpolar atmospheric winds and a limited human intervention. Industrial contamination is at a minimum level - if any -  which should be kept this way for  years to come, thanks to the latest international treaty agreements that have been set.

Therefore, heavy metals found in this area come primarily from volcanic activity, the main estimated pollutant source for Antarctic marine species (Knox, 1970; Berkman, 1992).

The Norwegian Institute of Nutrition [Directorate of Fisheries N-5804 Bergen, Norway] has done extensive research in this topic. It analyzed materials classified as undesirable for animal feeding purposes such as arsenic, fluorine, cadmium, lead and mercury. Through their Norwegian Agricultural Inspection Service, it presented several proposals (Amended proposal, December 2000) to the EU commission in order to change EU’s heavy metal level restrictions for feed ingredients restriction, among them krill meals.

Arsenic (As) from volcanic sources is a natural element found in water, soil and air. In marine species it comes in its organic [80%-99%] non-toxic form, plus its inorganic form, the latter found in an amount of less than 0,01ppm As/Kg wet weight. Fish have 1-10ppm of As/kg wet weight. The EU regulation states 10ppm total Arsenic content for feeding stuffs from fish or other marine animals. In whole krill, Arsenic level reaches 3 ppm As/Kg (Deheyn, D. et al , 2000).

Cadmium (Cd) and Lead (Pb), Cd from volcanic activity and human contamination through wastewater, fertilizers and air pollution. Pb comes from industrial contamination (batteries, solder, and alloys).

Both metals have a low accumulation rate in fish’s flesh. (Norwegian Agricultural Inspection Service, Amended proposal. December, 2000). Data for brown and white fishmeals and krill meals show that Cd and Pb levels fall within EU’s Directive 2002/32/EC.

Cadmium and Lead levels (*)
Antarctic Krill Meal and Fish Meal

Material

Antarctic krill meal

Mean(ppm) n=4

Norwegian fish meal

Mean(ppm) n=15

Feed Material

EU Regulation

Upper Limit

Cadmium

  0,1

0,45

 2,0

Lead

< 0,5

0,43

10,0

(*) Regular brown & white fishmeals have a Lead average content of 3,72ppm (IFFO 1976)

Mercury (Hg) is widely distributed in nature, found in water, soil, air and in several organisms. In marine species, organic mercury (methyl mercury) is considered a toxic compound, thoroughly concentrated throughout the food chain.  Inorganic less-toxic mercury is accumulated at lower concentrations.

Methyl mercury found in fish feeds is accumulated in fish’s flesh and it is slowly eliminated. Tuna, halibut, sharks, and other predatory species accumulate higher mercury concentrations (0.5 " 1 ppm wet weight). The opposite is valid for species found at the beginning of the food chain, such as Antarctic krill that fed from plankton. It accumulates mercury at less than 0.1 ppm (wet weight).

Mercury in Antarctic krill Meal (*)

Krill Meal

Mean(ppm)

 N=6

Complete Fish Feeds Mean(ppm)

n=54

EU upper level for feed material

Mean(ppm)

EU limit for complete feeds

Mean(ppm)

< 0,05

0,05

0,5

0,1

(*) Regular brown & white fishmeals have a Mercury average content of 0,15ppm (IFFO 1976)

Krill meal mercury levels easily falls within EU regulations and are a suitable and safe feed ingredient.

Dioxins
Dioxins are a group of 210 polychlorinated substances spontaneously created from  industrial contamination and wastewater -  mainly from cellulose plants. From these, 17 are considered toxic and these are targeted in lab analysis.

Dioxins are  a serious toxic material and active at very low dosage; they accumulate in fatty tissue and are not easily eliminated, either in marine species or humans. The EU directive is set at a maximum level for fishmeals of 1.25 ng-WHO-TEQ/kg product.

Dioxin content in South Antarctic Krill Meals
Expressed as ng-WHO-TEQ/kg

Orkney Island

Jan.26-Feb.28 2002

Orkney Island

Mar.15-Apr.18 2002

South Georgia’s

Jun.22-Jul.31 2002

EU max level for fish meals

0,2657

Fat 13,0%

0,3259

Fat 13,9%

0,2054

Fat 12,9%

1,25


(*) Average value

Since Antarctic krill meals are well within the limit established by the EU, it gives the fish feed manufacturer a greater safety margin, particularly if some of the other fish meals and oil feed ingredients used are closer to the limit. 

References

Knox, G.A. (1970). Antarctic Marine Ecosystem. Antarctic Ecology Academic Press, London, pp 69 " 96.

Berkman, P.A. (1992). The Antarctic Marine Ecosystem and humankind. Reviews in Aquatic Sciences 6, 295-333.

Norwegian Agricultural Inspection Service (2001). Amended proposal for a Directive on undesirable substances and products in animal nutrition. COM (2000) 861 final.

Deheyn D., Gendrau P. , Baldwin R.J. , Latz M. I. (2000). Characterization of metals contamination in the marine ecosystem of Deception Island, Antarctica. In Marine Biology Research Division, Scripps Institution of Oceanography University of California, San Diego, La Jolla, Ca, USA.
 
Canadian Food Inspection Agency (2002). Summary Report of Contaminant Results in Fish Feeds, Fish Meal and Fish Oil.

See also: “First Report on The Fluorine in the Antarctic Krill meal” 
The Krill

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