Golden mussel detected in California for first time using environmental DNA

The golden mussel (Limnoperna fortunei), an invasive bivalve native to south-east Asia, has established itself across South America since its arrival in the 1990s, causing substantial ecological and economic disruption. A preprint posted to bioRxiv now reports its first confirmed genetic detection in North America, in California, marking a significant extension of its invasive range.

The authors describe the development, optimisation, and field deployment of an environmental DNA (eDNA) monitoring protocol for the species. Environmental DNA methods detect genetic material shed by organisms into water, enabling surveillance without direct capture of individuals — particularly valuable for early detection of low-density invasions. The protocol was validated against tissue samples and then applied to field water samples, yielding the first confirmed detections.

The authors note that early detection is critical for informing containment and management responses, and that eDNA-based approaches offer a scalable route to ongoing monitoring. The work also demonstrates the utility of eDNA surveillance frameworks developed for other aquatic invasives in being adapted to new target species.

The preprint has not yet undergone peer review. Confirmation and ongoing monitoring efforts will depend on agency responses and the operational deployment of the described eDNA procedures.