Catch records of sawfishes at Eighty Mile Beach, Western Australia, and the identification of a potential nursery area using decades-old rostra

Objective In this study, we provide historical records of sawfishes (family: Pristidae) captured by commercial fishers at Eighty Mile Beach, Western Australia, during the early 21st century. Using rostra donated by members of the public and unpublished catch data, we provide information on the occurrence of pristids in Western Australia and identify important habitats for these rays. Methods Species identifications were conducted for rostra based on the meristics and morphology of specimens, with specific reference to the number, spacing, and physical attributes of rostral teeth. Results Donated rostra comprised 17 specimens, which represented all four sawfish species that occur in the Indo-West Pacific: the Narrow Sawfish Anoxypristis cuspidata (n = 5), the Dwarf Sawfish Pristis clavata (n = 6), the Largetooth Sawfish P. pristis (n = 1), and the Green Sawfish P. zijsron (n = 5). Standard lengths of rostra suggested that one Largetooth Sawfish and one Green Sawfish were mature upon capture. Remaining specimens were estimated to have belonged to juveniles, including two Narrow Sawfish, two Dwarf Sawfish, and four Green Sawfish that were estimated to be less than 1 year of age. Additional individual catch records of immature sawfish were collated for 19 Narrow Sawfish, 15 Dwarf Sawfish, and 25 Green Sawfish encountered at Eighty Mile Beach and adjacent Cape Keraudren between 2003 and 2008. Conclusions The sizes of donated rostra, combined with historical catch data, suggests that the nearshore waters of Eighty Mile Beach and Cape Keraudren may have served as a nursery area for Narrow Sawfish, Dwarf Sawfish, and Green Sawfish during the early 21st century. Given the cessation in commercial fishing activities and introduction of protection measures for these sites over the past two decades, it is possible that these sites function as a nursery for sawfish in the present day.