Conservationists are urged to be cautious when moving animals to new locations to avoid risk of spreading disease
Conservationists may be unintentionally spreading diseases and parasites between threatenedanimalpopulationswhen they move animals to a new location, research suggests.
A Cambridge University study indicated that mixing populations of freshwater mussels risks the spread of gonad-eating worms, which can lead to the collapse of populations in extreme cases.
While the study focused on freshwater mussels, one of the most endangered animal groups globally, it is applicable to all species moved around for conservation purposes, according to the researchers.
Dr David Aldridge, of Cambridge's Department of Zoology, said: "We need to be much more cautious about moving animals to new places for conservationpurposes,asthecosts may outweigh the benefits.
"Mixing different populations of mussels can allow widespread transmission of gonad-eating worms, it only takes one infected mussel to spread this parasite, which in extreme cases can lead to collapse of an entire population."
Mussels play an important role in cleaning the water of many of the world's rivers and lakes.
There is growing interest in moving mussels to new locations to boost threatened populations, or so they can be used as biological filters to improve water quality.
A gonad-eating parasitic worm, Rhipidocotyle campanula, which can leave mussels completely sterile, was identified in the study as a huge risk for captive breeding programmes where mussels from many isolated populations are brought together.
In other cases infections may not cause a problem unless they are present when other factors, such as lack of food or high temperatures.
The report recommends that species are only relocated when absolutely necessary and quarantine periods, tailored to stop transmission of the most likely pathogens being carried, are used.
Josh Brian, a PHD student in Cambridge's Department of Zoology, said: "Moving animals to a new location is often used to protect or supplement endangered populations.
"But we must consider the risk this will spread pathogens that we don't understand very well at all, which could put these populations in even greater danger."