Foraging ecology of flatback turtlesProject lifecycle
What? Daily diaries (i.e. data loggers collecting accelerometry data, orientation data and swimming performance data. The equivalent of a 'fitbit' for a turtle) are deployed on flatback turtles in order to collect the fine scale data on their diving behaviour and swimming performances at a foraging ground.
Why? This PhD project aims to improve our understanding of flatback turtles using biologging tools (i.e. daily diaries and animal-borne video cameras) to analyse their fine-scale vertical and horizontal movements, providing the first quantitative insights of in-water behaviour at a recently discovered foraging ground. Jenna will elucidate the temporal and spatial drivers of behaviours that serve critical life history functions, such as foraging (important for energy gain) and rest (important for reducing energy expenditure). The anticipated outcome of this PhD project is to assess how flatback turtles might be impacted by anthropogenic disturbances at their foraging grounds.
What have we found? Hounslow JL, Jewell OJD, Fossette S, Whiting S, Tucker AD, Richardson A, Edwards D, Gleiss AC. (2021) Animal-borne video from a sea turtle reveals novel anti-predator behaviours. Ecology. doi:10.1002/ecy.3251
Who are our partners? Murdoch University, DBCA Broome office, Customized Animal Tracking Solutions (CATS), Yawuru rangers
Studying the diving behaviour of flatback turtlesProject lifecycle
What? Daily diaries (i.e. data loggers collecting accelerometry data, orientation data and swimming performance data. The equivalent of a 'fitbit' for a turtle) are deployed on flatback turtles in order to collect the first fine scale data on their diving behaviour and swimming performances.
Why? No fine scale data on diving behaviour and swimming performances exist for flatback turtles. This is surprising considering that over 200 papers are available for all other species of turtles and their diving behaviour, swimming speeds, etc, have been studied in detail. An understanding of the diving behaviour and swimming performances of free-ranging flatback turtles is critical to understand their basic at-sea ecology and biology and in turn mitigate the impact of anthropogenic threats such as lights, dredging, and oil spill on this species.
What have we found? Daily Diaries have been deployed on ten flatback turtles, both male and female, in the inter-nesting and foraging areas. The loggers collected weeks worth of data that are currently being analysed.
Who are our partners? Murdoch University, DBCA Broome office, Customized Animal Tracking Solutions (CATS), Yaaruu rangers
Mapping flatback turtle foraging areas in the Kimberley
What? This project will identify and characterise key foraging habitats used by sea turtles (predominantly flatback turtles) in the offshore water (30-100 m depths of the Kimberley coast and collect benthic habitat specimens for stable isotope analyses to provide insight into diet.
Why? Post-nesting satellite tracking studies of sea turtles over multiple years have revealed foraging “hotspots” or preferred habitat by flatback turtles. These areas appear to be stable inter-annually and are used by the turtles from different rookeries and also used by other species such as olive ridley and loggerhead turtles.
This study used tracking data from various sources to identify foraging hotspots and to maximise resources from WAMSI Kimberley Node Benthic Project to extend benthic surveys into these areas. This will be the first dedicated study of flatback turtle foraging habitat.
What have we found? The survey concentrated on the Lynher Bank, an offshore mid-shelf area north-west Cape Leveque. The faunal composition was dominated by non-scleractinian sessile organisms associated with soft bottom habitat with high water movement and low wave action. The lack of algae and the non-zooxanthallae corals was consistent with the low light benthic conditions.
Who are our partners? WAMSI, AIMS, CSIRO, DBCA
Understanding movements and identifying important habitatsProject lifecycle
What? To understand the connectivity between rookeries and foraging grounds including identifying inter-nesting habitat and behaviours, migratory paths and foraging grounds and behaviour.
Why? Spatial understanding of turtles during all life stages is important for managers to understand how potential pressures may impact the population. This information assists spatial planning for marine parks and reserves and also informs fisheries and other resource users.
What have we found? Four species (flatback, green, hawksbill, loggerhead turtles) have globally significant nesting numbers and foraging habitats across the Kimberley, Pilbara and Gascoyne. Olive ridley turtles are sparse nesting on marginal ranges in the Kimberley, and leatherback turtles are not nesting but have migratory corridors through WA waters.
Who are our partners? DBCA regional offices (Denham, Exmouth, Karatha, Broome, Kununurra) and Marine Parks