I received an email from a correspondent, Jo, which led to ideas
H5N1 Bird Flu Maybe Linked to Fish Farming
Also noticed on this list of articles (link below) information about farmers in Vietnam accused of dumping at least 100 tonnes of chicken manure a day into a lake to feed the fish - I rest my case!
- sent out an email re this to several people interested in H5N1 and conservation; led to flurry of info. - notable partly as mute swans dying of H5N1 in Croatia (with one of them ringed in Hungary during prior stopover, with dates showing it surely didn't carry H5N1 from Siberia, but likely caught in Croatia); also in Romania, where a BBC report mentioned over 80 swans dying on a fishpond. Info including:
As far I know this [using chicken faeces for feeding fish] is traditional habits in et least Ex Jugoslavia, so very probably also in Croatia.
last year I was working on grey partridges near Varazdin, north of the current outbreaks. The area (northern Slavonia) has a lot of small-scale (10 sheds or so) but intensive chicken-rearing due to the large quantities of wheat and maize raised in the area. Lots of the produce goes to Austria and Slovenia. As I went around the fields I was shocked to find large quantities of fresh chicken manure (together with the odd dead chicken) piled up here and there around the fields. I asked the gamekeeper and he told me that for a small fee the farms will deliver manure wherever you ask them to. It's left to weather down in the fields, often next to drainage ditches and streams.
In Czech Republic they fertilise carp ponds with NPK to produce a green soup of algae in the ponds. There are plenty of carp rearing set-ups in Slavonia.
From my research on storks in Israel I remember that at most ponds there was a place where manure from Turkey & Chicken was put and spread in the ponds. Probably a common practise.
In relation to fish-related issue, it would be worth paying attention to fish as a potential carrier of the virus. At least one Orthomyxoviridae virus (Isavirus, salmon virus) infects fish. This virus is thought to have originated from avian influenza (or the reverse). In addition to chicken manure, import of fry in fish raising is popular, and it would be meaningful to experimentally test whether some fish species can maintain the influenza virus.
more from Jo:
1.http://news.bbc.co.uk/1/hi/world/europe/4347860.stm Romanian villages tackle bird flu ………………… like the fish farm behind Maliuc, ………………………..
2. In recent years pond fisheries have begun to develop in Siberia, the Urals and northern Kazakhstan.
3. The importance of poultry wastes in aquaculture is relatively recent. In areas of traditional fish culture, ruminant and pig manure have predominated as pond fertilisers in the Subcontinent and China respectively. Poultry manure was not used to any extent probably because small flock size and extensive management precluded collection. Poultry production wastes have inherent qualities that make them particularly valuable for fish production compared to other livestock wastes (Table 1).
Poultry wastes are more nutrient dense than other livestock wastes. Typically they contain less moisture, fibre and compounds such as tannins that discolour water when used as fish pond fertilisers. Commercial `feedlot' production leads to concentration of nutrient-rich waste which can be handled and transported cost-effectively. This may mean that the opportunity costs of poultry manure are higher, and their use for horticulture particularly is common.
The small individual size of poultry also allows their confinement and production directly over fish ponds. Poultry manure is now widely used in commercial freshwater aquaculture. In central Thailand, use of livestock wastes is the norm in the production of cheaper herbivorous fish.
Poultry processing byproducts such as chicken bones, intestines and whole carcasses have greater value as `direct' feeds and are normally used for higher value fish species raised more intensively. High fish standing stocks can be maintained and yields produced using this type of product and management. Processing wastes can be used fresh, or after further processing, as good quality supplementary, or complete, feeds.
Poultry manure is used either directly on-site, through the siting of poultry houses over ponds, or after collection, storage and transport to the site of fish culture. Construction of the poultry house over the pond allows waste to drop directly in. Poultry slaughterhouse wastes are in great demand for feeding hybrid clarias catfish (Clarias macrocephalus x Clarias garipinus) in Thailand.
There has also been implicit connections made between integrated livestock-fish systems and influenza pandemics (Scholtissek and Naylor, 1988); this disturbing theory has led to widespread comment and discussion of the desirability and impacts of integrated farming (Edwards et al., 1988; Morse,1990; Skladany,1992 ). The theory maintains that integrated aquaculture encourages the raising of pigs and poultry together to provide manure for fish and that this in turn increases the risks of new forms of influenza developing……….
Also, from another interested party:
Chicken manure-related reference: http://www.chp.gov.hk/files/pdf/grp-spe_v13n1-en-2004052100.pdf "Public Health & Epidemiology Bulletin" Avian influenza virus can survive, at cool temperatures, in contaminated manure for at least three months. Lethal dose of contaminated water:
"Routes of infection of highly pathogenic avian influenza in Japan" Contaminated water can be considered the most dangerous route of infection. When 1g of feces (10 million virus particles) was dissolved in a tub (100L), the virus density was 100 particles/ml of water; actually, however, uric acid in the feces has the effect of weakening this. However, even water that is contaminated with virus of very low density, the lethal dose for the establishment of infection in chickens is about 300 particles and, if about 200ml of water per day is ingested, there is the possibility the chickens could become infected... (Although this report mentions wild birds, the true route of invasion was not yet clarified).
Chicken manure does seem to be very popularly used: "The Economic Benefit of Chicken Manure Utilization in Fish Production in Thailand"
"Public, animal, and environmental health implications of aquaculture" The abuse and misuse of raw chicken manure as pond fertilizer may result in the transmission of Salmonella from manure to the cultured product. (Philippins) ...
The same would be true for H5N1.
"Nitrogen Flow in Can Tho Province" It was regarded that chicken manure from large chicken farms was exported to surrounding provinces (Thong, private communication). (farming system in Mekong delta) Pellet form of chicken manure (Thailand):
You probably able to find whatever you may imagine...
While here an article on: Poultry and fish production-a framework for their integration in Asia - includes:
one hectare of static water fish ponds can `process' the wastes of up to 1500 poultry, producing fish in quantities of up to 10 MT/ha without other feeds or fertilisers. Also, since effluents are few, environmental impacts are minimal. ...
The importance of poultry wastes in aquaculture is relatively recent. ...
Poultry manure has been used widely in both fresh and brackish water aquaculture. In the latter, Penaeid shrimp, Milkfish (Channos channos) and Tilapia (Oreochromis sp.) have been the principle species raised (figure 1). Inland culture systems in which poultry and fish such as the carps, tilapias and catfish are raised in commercial and subsistence sytems are the focus of this review. Poultry manure is now widely used in commercial freshwater aquaculture.
- see also Farm fish fed dead chickens in Indonesia on this site; has photos from a couple of farms in Java.