The extent of amphibian, fish and water plant translocations by garden pond owners

Some people move plants and animals to or from their garden ponds. Translocations by garden pond owners might contribute to the spread of pathogens and species, but generally go undocumented. We therefore conducted an online survey targeting Dutch garden pond owners through various relevant communication channels and hobbyist groups to explore the extent (frequency, distance and number) of fish, amphibian and water plant translocations. A total of 563 questionnaires were returned, of which 556 were suitable for analyses. Our findings show that all species groups are occasionally collected from natural areas, with plants more often collected than fish and amphibians. When removed from garden ponds, amphibians were translocated to natural water bodies in 70% of the cases, which was more often compared to fish (24%) and water plants (7%). In total, 19% of the 732 documented translocations involved alien species, of which nine alien plant and sixteen alien fish species could be identified. The distances over which animals and plants were transported ranged between 8 m and 260 km. Our study shows that translocations of animals and plants by garden pond owners are common and that motivations of people can differ. Further quantification of these translocations is vital to better assess the relative impact of this pathway on the spread of invasive alien species and pathogens. Better information, including repeated communication and a best practices protocol, is required to raise awareness among pond owners.