Standard Presentation Australian Marine Sciences Association Annual Meeting 2023

Snubfins as sentinels of Yawuru sea country (#284)

Holly C Raudino 1 , Jason Richardson 1 , Anthony Richardon 2 , Dean Mathews 3 , Leroy Pigram 3 , Vaughan Lee 3 , Julie Melbourne 3 , Luke Puertollano 2 , Peter Roe 2 , Wil Bennett 2 , Kevin Crook 1 , Todd Quartermaine 2 , Ellen D'Cruz 2 , Kelly Waples 1
  1. Dept Biodiversity, Conservation and Attractions, Perth, WA, Australia
  2. Dept Biodiversity, Conservation and Attractions, Broome, WA, Australia
  3. Nyamba Buru Yawuru, Native Title Prescribed Body Corporate, Broome, WA, Australia

The highest density of snubfin dolphins (Orcaella heinsohni) in Australia (~130) inhabit Yawuru Nagulagun in Western Australia. In 2016, a marine park was created in Yawuru Nagulagun; jointly managed by Yawuru Native Title Prescribed Body Corporate and the Department of Biodiversity, Conservation and Attractions (DBCA) with snubfin dolphins a recognised value of the marine park. Prior to 2016, snubfin population estimates were produced from regular surveys over several months. In April 2019 and May 2022, Yawuru and DBCA completed intensive rapid population censuses over a few days, as an alternative strategy to monitor this population. The censuses recorded 96 and 87 unique snubfins, respectively, based on the high degree of marking of dorsal fins in the population (~83%). Snubfin density and distribution has remained similar between censuses and 28% and 44% of individuals identified respectively were resighted from previous years (including one from 2007), providing demographic data. The high intensity rapid census approach has proven successful for monitoring the snubfin population. We recommend that census-style surveys are repeated every 2-3 years to detect and manage any changes in the snubfin population. This is an example of a successful jointly managed monitoring program of an important value within a marine park.