- Effective measures are possible by early detection of their invasions into reservoirs. -
The National Agriculture and Food Research Organization (NARO) has developed a highly sensitive detection method for the invasive alien species golden mussels (Limnoperna fortunei) using environmental DNA analysis. Golden mussels can be found in large numbers in waterways and reservoirs, which causes problems such as obstruction of water flow and adverse effects on the ecosystem of native species. However, it was difficult to detect them in the early stage of invasion due to their low density. This research will be effective in the early detection of golden mussels and quick countermeasures against the damage caused by them.
NARO has developed a technology to detect golden mussels, which causes water flow obstructions in irrigation facilities, etc., at a low-density stage shortly after their invasion.
Golden mussel is an alien bivalve species that causes damage to the operation of irrigation facilities, such as clogging water pipes for agriculture. In Japan, golden mussel was first recorded in 1992, in Lake Biwa. Since then, it has been confirmed to inhabit 12 prefectures in the Kanto, Tokai, and Kinki regions. It has been reported that the distribution has expanded via waterways, etc., in recent years. Hence its early detection and quick countermeasures are required.
The population density of golden mussels is low at just after the stage when it invades a reservoir. Hence it has been a problem to supervise its habitat in conventional surveys such as visual inspection. Therefore, we developed a survey method to detect DNA derived from the mussel contained in water samples collected locally. Then its effectiveness was compared and examined with the usual survey methods. It was found that the survey method using environmental DNA analysis is more efficient in detecting the mussels than the conventional visual observation and larval survey.
Environmental DNA surveys that use small amounts of water require only a little effort and have little impact on water management. This method is suitable for surveys at water facilities that have not yet been invaded or damaged by the mussels.