A rookery with 300 turtle nests per season is considered to be a significant turtle…
On 25 November 2010, just before I left Gnaraloo for my formal turtle monitoring training by CCG and DEC in Exmouth, Karen arrived onsite to help us further develop turtle conservation strategies, update procedures, design new protocols and discuss several issues facing Gnaraloo’s turtle nesting population
A research team from the University of Western Australia (UWA) comprising of Dr Nicola Mitchell, Lorian Woolgar and Sam Robinson arrived to conduct the first of their field surveys and data collection. The work carried out by UWA researchers at Gnaraloo is additional to the research being undertaken under the GTCP and aims to answer the question of where male Loggerhead hatchlings are being produced in Western Australia (WA). This is being done by (1) predicting the sex ratio and rate of embryonic mortality of turtles hatching at current nesting sites in WA, such as Gnaraloo, and (2) by examining whether changes in the timing or distribution of nesting activity could be an adaptive response to climate change.
A researcher from James Cook University, Queensland, Taylor Bodine who is supervised by Dr Mark Hamann, also arrived to undertake field monitoring and data collection. This work is separate to the research efforts of the GTCP and UWA. It investigates nest site selection in order to determine how vulnerable Loggerhead nesting turtles are to climate change in WA.
For GTCP survey results, the beginning of December was relatively busy in terms of turtle activities (12 – 15 noted per day). We also commenced night surveys in order to be able to confirm the accuracy of the day monitoring data (for species identification and for nests vs. unsuccessful nesting attempt results).
Given the presence of a significant population of Ghost crabs (including, but not limited to, Ocypode convexa et O. ceratophthalma) being observed by GTCP researchers since 2008, and again noticing ongoing disturbance to and predation of turtle nests by crabs during 2010/11, we are now formally investigating the density, temporal and spatial distributions of Ghost crab populations along the Gnaraloo monitored rookery.
On 16 December 2010, strong winds brought dark clouds and unusually heavy rains to Gnaraloo. It rained for 2 nights and 2 days (about 300mm). While no buildings were inundated, all roads and tracks around Gnaraloo were impassable for at least a week. We missed 1 day of monitoring because we couldn’t reach the surveyed area with the Turtle-wagon due to flooding and had to undertake a 30km walk for a couple of days in order not to lose too much data! While the climatic events didn’t stop the nesting season or prevent the females from nesting on the beach, we noticed a large amount of changes in terms of beach profile due to storm surges and tidal erosion and recorded that a significant percentage of the clutches were inundated.
By the end of the season, we will be able to assess the impacts of the floods on turtle nests and hatching success. Let’s hope that most of the hatchlings will be able to hatch, emerge from the nests and make their way to the ocean.