Read Time: Moving endangered species to new locations is often used as part of species conservation strategies, and can help to restore degraded ecosystems. But scientists say there is a high risk that these relocations are accidentally spreading diseases and parasites. The new report published today in the journal Conservation Letters focuses on freshwater mussels, which the researchers have studied extensively, but is applicable to all species moved around for conservation purposes. Mussels play an important role in cleaning the water of many of the world's rivers and lakes, but are one of the most threatened animal groups on Earth. 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.