Fish as feed inputs for aquaculture: practices, sustainability and implications

Fish as feed inputs for aquaculture – Practices, sustainability and implications: a global synthesis 41

be expected in mammals, birds and fishes exposed to the current levels of background
pollution”. Despite this, a considerable proportion of the population of Europe (and
undoubtedly other regions) is exceeding the tolerable weekly intake (TWI) levels for
dioxins set by various authorities. As there is a considerable safety factor imposed
on TWI, this does not necessarily mean that there is an appreciable risk to individual
health. However, exceeding TWI levels erodes the protection of this safety factor.
Food contributes more than 90 percent of our daily dioxin intake (EC, 2001). Our
exposure to dioxins and PCBs is decreasing (by a factor of about 50 percent over the
last 10–15 years) due to improved waste management and restrictions on the use of
these materials.

6.3.2 Transmissible spongiform encephalopathy (TSE)
It is important to state that there is no epidemiological evidence for the transmission
to humans of a variant of CJD caused by prions that use fish or fish products as
vectors.
A temporary EU ban on the use of animal proteins in certain livestock feeds was
approved in 2000 (Commission Decision 2000/766/EC over the period to June 2003,
since extended to June 2005). The main purpose of the action by the EU was the removal
of meat and bone meal from European animal feeds, together with the destruction of
stocks of this material, in an effort to contain the spread of BSE. A permanent TSE
Regulation (1234/2003) amending regulation 999/2001 covering feed controls came
into effect in September 2003 (although the ban on the use of blood products and blood
meal was lifted). The ban EU is currently still in force at the time of writing.
The EU ban on the use of animal proteins includes the use of fishmeal in ruminant
feeds but does not ban its use in feeds for pigs or poultry or in aquafeeds. The ban
on the use of fishmeal in ruminant feeds was initiated because meat and bone meal has
unfortunately been used at times to adulterate fishmeal in order to alter its protein
content. The ban causes a further problem for feed manufacturers, in that cross-
contamination may occur between batches of feeds made for one type of livestock and
batches made for other types of animals; the current EC regulation has a zero tolerance
and thus manufacturers have been forced to mill ruminant and non-ruminant feeds at
different factories.

7. REGIONAL ISSUES ON THE USE OF AQUATIC SPECIES AS FEED FOR
   AQUACULTURE
   7.1 Europe
   Given the high level of dependence of European aquaculture on compounded feeds
   in intensive systems, the issues of regional importance reflect the sourcing of raw
   materials for feeds rather than the environmental impact of their actual use. Three
   issues are of immediate concern.
   
   
   • Improved sustainable management of feed-fish stocks: Feed fisheries, which are
     largely composed of small, bony pelagic fish, require quite distinct management
     approaches compared with the often larger and slower-growing fish harvested for
     direct human consumption. As described earlier in this report, management of
     feed fisheries needs to recognize the dynamic turnover of the stock and the high
   
   
   
   

TABLE 12
Current EC limits on dioxins in fishmeal, fish oils and aquafeeds
(ng/kg product)
Product Maximum level Action level
Fishmeal 1.25 1.00
Fish oil 6.00 4.50
Compounded fish feed 2.25 1.50