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2007/08 Grant funded projectsDr Ivan Lawler and Mr Dave Holley To enhance understanding of dugong large-scale movements and sub-tidal habitat use by assessing the potential of the innovative Fastloc GPS technology to mitigate the sampling biases inherent in tracking dugongs using GPS tags, which provide few location fixes from animals in habitats deeper than ~3m and/or moving quickly. The new generation Fastloc technology should increase the chances of recording an animal's location irrespective of its speed and location. The resultant improved understanding of the large-scale movements and sub-tidal habitat use of dugongs will inform policy for managing important dugong habitats.
The aim is to estimate Australian fur seal pup numbers at all colonies following the 2007/08 pupping period. This will repeat the first thorough census of pup numbers at all breeding sites conducted in 2002/03. Current data on population sizes and trends are important for understanding and conservation of marine mammals. Australian fur seals are endemic to Bass Strait, breed at 10 sites and are the marine mammal that reportedly interacts most frequently with fisheries in Australia. The 23,000 pups estimated in 2002/03 represented a near-doubling of numbers since the 1970s, when seals became protected species. Is this trend continuing?
This project will result in a new computer-based photo-recognition matching system that efficiently identifies individuals and finds resights in photo-identification catalogues of humpback whales. This project builds on previously successful research using a unique multifaceted computer-based recognition system to overcome the overwhelming problems of manually matching photographs of humpback whale flukes in large catalogues. The new system provides a rapid and improved method of obtaining mark-recapture data (RP4a) for abundance estimates and trends (RP1a), independent movements and levels of interchange among populations of humpback whales (RP1c) in Australia and the South Pacific for improved management and conservation outcomes.
The project will complement a major existing data set from surveys undertaken in 1999 and 2005 on northward migrating humpback whales from one of seven currently recognised southern hemisphere breeding stocks (Breeding Stock D). As in 2005, there will be two components (i) an aerial survey over two months, covering the peak migration period past Shark Bay, WA, where regular aerial surveys provided relative abundance and trend information over 1982-1994; (ii) a land-based survey over a shorter period, to 'ground-truth' the aerial survey. The result should be an estimated current absolute abundance for this Breeding Stock, together with a comparison with 2005 and 1999 results, for use in comprehensive assessments of southern hemisphere whale stocks, essential for their conservation and rational management.
The conservation and management of many marine mammal populations relies on accurate and precise estimates of their abundance and distribution using aerial surveys. We aim to test whether Unmanned Aerial Vehicles (UAVs) can replace manned aircraft to (1) reduce costs, (2) reduced human risk, (3) deliver superior data on detection, location, abundance and identification of marine mammal species. This project aims to (1) develop and test technology and techniques for UAV surveys and (2) conduct and compare traditional manned and UAV surveys of dugongs and humpback whales to test the viability of UAV surveys.
Previous Humpback Whale Acoustic Research Collaboration (HARC) experiments successfully developed a methodology for performing Controlled Exposure Experiments (CEEs) and measuring the behaviours of humpbacks at multiple resolutions, in a well defined study area. This project will concentrate on CEEs and (1) document the range of behavioural reactions observed by the whales, (2) measure the received acoustic levels that elicit reactions, and (3) place the range of reactions observed into the context of normal behaviours for these whales at this site. This project will improve our knowledge of the effects of anthropogenic noise on humpback whale behaviour and acoustic communication.
This project will investigate the movement patterns and population size of the pygmy blue whales that aggregate off south-western Australia each autumn. Currently it is not known if these animals represent a sub-population or if they range-widely and form part of a larger population with linkage to other known aggregations in Australian waters. We will deploy small, biologically inert, implantable satellite-tags to investigate the movements of these whales and, through supplement existing data, employ genetic tagging and photo-identification data to estimate population size and the recurrence of the same individuals between years.
Through the genetic analysis of biopsy samples collected in north-western and south-eastern Australia this project aims to reveal:
This project aims to develop and validate stable isotope methods to distinguish different foraging ecotypes (inshore and offshore) among Australian sea lion (ASL) adult females and their dependent pups, and use pup sampling to screen the foraging ecotype profiles of ASL subpopulations. Molecular genetic analysis of the same pups will then be used to assess the importance of geographic distance and foraging ecotype in defining genetic population structure. These advances will be used to improve subpopulation based foraging models to assist spatial management of fisheries, improve our understanding of genetic population structure, and develop appropriate population surveys for the species.
Traditional methods of censusing Australian sea lion populations have used visual counts of pups during the peak of the protracted pupping season to provide a point estimate that can significantly underestimated pup production. As a consequence, quality time-series data on the status of populations are essentially absent. This proposal aims to role out a population survey strategy at key colonies in South Australia. These surveys will enable accurate estimation of pup production with confidence limits, and methods will be tailored for different sized populations. Effective management and recovery of Australian sea lion populations will need to be underpinned by an ability to detect changes in the status of populations over the shortest possible time-periods. This proposal builds upon a project funded by NHT/ACAMMS in 2006/07 to develop new population monitoring methods for the threatened Australian sea lion. Accurate knowledge of diet is essential for understanding marine mammal behaviour, ecosystem dynamics and potential impacts of fisheries. Traditional diet determination, through analysis of prey hard parts in faeces, is biased by differential prey recovery. Recent research shows this problem can be overcome through DNA-based faecal analysis. We will carry out a comprehensive analysis of prey DNA sequences in faeces collected from the Australian fur seal, Arctocephalus pusillus doriferus, using recently developed pyrosequencing technology. This novel approach of population-level dietary genotyping will provide a new perspective on diet of a key marine predator in Australian waters and provide a template for future diet studies on other pinnipeds, whales and dolphins.
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