The Controversies Regarding the Native Range and Impact of the Rusty Crayfish

Session: 03. - Science and Policy for Management of Invasive Crayfish

Radu Guiasu, Glendon College, York Univ., Biology Program, [email protected]
Mark Labib, Glendon College, York University, [email protected]
Gureet Kang, Glendon College, York University, [email protected]

Abstract

Orconectes rusticus is considered to be invasive in many parts of North America, including Ontario, and is the target of control programs. However, the limits of the native range of this species, as well as its means and rate of dispersal, are uncertain, and it is quite possible that this crayfish may in fact be native in parts of the continent where it is now considered to have been introduced by people. We examined the available distribution records in the Royal Ontario Museum database, as well as the relevant literature, and determined that the historic distribution records for this species in Ontario are very scarce and incomplete, and therefore cannot offer a reliable basis for reconstructing the history of this species in this province. The rusty crayfish can certainly expand its range into Ontario without human assistance. Furthermore, the impact of this species can be uncertain, variable, and not fully understood. The current focus on the negative impact of this species appears to be driven by the "invasive" status somewhat arbitrarily assigned to this crayfish, and neither this focus nor the assigned status may always be justified by the available evidence. 

1. Keyword
crustaceans

2. Keyword
invasive species

3. Keyword
biodiversity

4. Additional Keyword
native range

5. Additional Keyword
Ontario

6. Additional Keyword
crayfish