Introduction of an alien fish species in the Pilbara region of Western Australia

WA Museum Records and Supplements | Updated 6 years ago

ABSTRACT – Until recently rivers of the Pilbara region of north Western Australia were considered to be free of introduced fish species. However, a survey of aquatic fauna of the Fortescue River conducted in March 2017 resulted in the capture of 19 Poecilia latipinna (Sailfin Molly) throughout a 25 km section of the upper catchment. This represented the first record of an alien fish species in the Pilbara region and the most northern record in Western Australia. Based on the size of the individuals captured, the distribution over which they were recorded and the fact that the largest female was mature, P. latipinna appeared to be breeding. While P. latipinna was unlikely to physically threaten native fish species in the upper reaches of the Fortescue River, potential spatial and dietary competition may exist if it reaches downstream waters where native fish diversity is higher and dietary overlap is likely. As P. latipinna has the potential to affect macroinvertebrate communities, some risk may also exist to the macroinvertebrate community of the Fortescue Marsh, which is located immediately downstream, and which is valued for its numerous short range endemic aquatic invertebrates. The current finding indicated that despite the relative isolation of the river and presence
of a low human population, this remoteness does not mean the river is safe from the potential impact of species introductions. Indeed, the presence of P. latipinna in this system highlights the potential for future introductions in other remote rivers of northern Australia where transient human populations, or those which fluctuate greatly with economic circumstance, are present.

Author(s) Dean C. Thorburn, James J. Keleher and Simon G. Longbottom
Volume
Records 33 : Part 1
Article Published
2018
Page Number
108

DOI
10.18195/issn.0312-3162.33(1).2018.108-114