Sawfish Population Monitoring for Ord Stage II

As part of the Ord Stage 2 Expansion, WRM were contracted by LandCorp (the proponent for the development on behalf of the Western Australian Government), to undertake surveys of the project area for the initial EIA, and subsequently to undertake three years data collection along the Keep River and adjacent control sites to establish baseline conditions. Sampling encountered three species of sawfish, all of which are listed under the Commonwealth EPBC Act as matters of national environmental significance.

As a result, Conditions were placed on the development by the Commonwealth Government which required sawfish populations in the Keep River to be monitored. WRM undertake annual fieldtrips to the Keep River and use Mark-Recapture techniques to monitor populations. This involves catching sawfish in nets, tagging the sawfish, and releasing them once DNA samples and body measurements have been taken. The sites are then resampled, and based on numbers of tagged fish recaptured, and number of new fish captured, the population sizes can be calculated. These data provide a baseline against which future changes may be assessed.