Invading the invaders: reproductive and other mechanisms mediating the displacement of zebra mussels by quagga mussels

Validated methodology for quantifying infestation levels of dreissenid mussels in environmental DNA (eDNA) samples

“…Both dreissenid species have a related native range, similar life histories and morphology340, and they are currently well expanded in Europe101519. The zebra mussel expansion typically occurs earlier131441 with an invasion lag time five times shorter than the quagga mussel144243. Quagga mussels become established in water bodies where zebra mussels are present710, and zebra mussel populations are gradually replaced by quagga mussels134344 with a complete replacement after nine of more years of coexistence14.…”

“…The zebra mussel expansion typically occurs earlier131441 with an invasion lag time five times shorter than the quagga mussel144243. Quagga mussels become established in water bodies where zebra mussels are present710, and zebra mussel populations are gradually replaced by quagga mussels134344 with a complete replacement after nine of more years of coexistence14. Thus, the lack of discrimination between these two species and the possible incipient quagga mussel specimens in the area studied is not a critical problem to implement the developed method, since regardless which of the two species are present the impact of the invasion is similar31314 or when species occurs concurrently, their effect is even greater14.…”

“…Since then, this species has expanded along the Ebro River and adjacent basins in the northeast region of the Iberian Peninsula1112. Moreover, these effects are expected to increase with the imminent arrival of another invasive dreissenid, the quagga mussel ( D. rostriformis Deshayes, 1838)101314. Around 2004 the quagga mussel arrived in Western Europe151617 and has been constantly spreading into areas where zebra mussels previously invaded181920, and thus are predicted to arrive to the Iberian Peninsula in a near future unless effective prevention measures are enacted10.…”

Biological and chemical contaminants as drivers of change in the Great Lakes–St. Lawrence river basin

“…Both introduced in the basin in the 1980s via ballast waters, these dreissenids have been identified as a contributor to cHAB development and anoxic conditions (Vanderploeg et al, 2001). Since the 2000s, quagga mussels appear to have displaced zebra mussels, which initially spread faster and farther, as the dominant dreissenid in many areas and both are now identified in all Great Lakes as well as in some tributaries (Ram et al, 2012). These mussels regenerate P and N in reactive forms available to algae (James et al, 1997).…”

Heading south: new records of the invasive quagga musselDreissena rostriformis bugensis(Andrusov, 1897) in France and further perspectives

“…Replacement of zebra mussel by quagga mussel is now well documented, having been observed at several locations in its initial expansion routes around the Black Sea (Dniepr, Don, Volga) as well as in Europe (Marescaux et al, 2015) and northern America (e.g. Stoeckmann, 2003;Wilson et al, 2006;Ram et al, 2011;Stewart, 2014). We can therefore expect an important expansion of the quagga mussel population in the Rhône drainage, including its tributaries, but also in the adjacent drainages: canals provide artificial pathways from the Rhône to the Seine, Loire and Garonne drainages (Fig.…”