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Title: Discovering and monitoring Antarctic wildlife populations by remote sensing
Author: Fretwell, Peter Thomas
ISNI:       0000 0004 5990 9016
Awarding Body: Open University
Current Institution: Open University
Date of Award: 2016
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The study of Antarctic wildlife is often logistically difficult; extreme weather conditions, poor transport links and the size of the continent make fieldwork challenging, expensive, and, in some cases, dangerous. Many regions of the continent are remote and distant from regularly visited research stations, so are still poorly explored, Previous wildlife monitoring studies have tended to be based close to scientific research stations, the distribution of which is uneven and clustered into a limited number of bio-geographic regions, which has left us with a biased and relatively poor knowledge of the population and distribution of many species of Antarctic vertebrates. The use of satellite remote sensing which can be low cost, frequent, and ubiquitous has allowed me to study wildlife in remote sites and to upscale existing point datasets into regional estimates. There is a pressing need for better information on Antarctic wildlife populations, this originates from two factors: the impacts of regional climate change on Southern Ocean predator populations; and, the impacts of commercial fishing for Antarctic krill (Euphausia superba) on krill-eating predators. Recent increases in krill harvesting mean that we urgently require better estimates of krill-eating vertebrate population sizes allowing better estimates of krill consumption rates. We also need better estimates of predator distribution and estimates of their population trajectories to enable sustainable harvesting, including the spatial management of fisheries. Generating estimates of vertebrate populations in the Antarctic by remote-sensing methods is made easier by the lack of vegetation and absence of terrestrial mammalian predators, meaning that seabirds and seals have no need to hide to the degree often found in other systems, burrow or camouflage their breeding sites. Many species therefore have a high visible contrast with their surrounding environment and often breed colonially in large groups, which, along with the lack of obscuring vegetation, makes them more easily visible by remote sensing. These characteristics mean that seabirds and seals in the Antarctic are potentially more-simple to count than in any other region of the globe. The urgent requirement to quantify wildlife populations and the high visibility of those populations to satellites, make Antarctic wildlife ideal candidates for census by remote sensing. The scientific field of wildlife and conservation remote sensing is expanding rapidly. When I started my work the number of papers using 'satellite imagery to map or estimate the abundance of Antarctic wildlife was limited, with one paper on emperor penguins and two papers on Adelie penguins which dated back to the 1980's. These papers were methodological papers studying a limited number of colonies and none of the techniques were deemed robust enough to provide realistic population data at the time of publication. Likewise the use of Very High spatial Resolution (VHR) imagery for census work was almost unknown. The papers introduced here developed new techniques that are accurate enough for robust population estimates using medium and VHR imagery, Critically, as well as developing those techniques the work also applied them to broad areas; in the case of emperor penguins enabling continent-wide population assessment of wildlife by direct observation for the first time. Today the-techniques and principles laid out in the papers below have been applied to many other species co-driven in-part by the ever-higher resolution of satellite imagery; which allows new species to be monitored as greater resolution becomes available. My expertise is in the application of remote sensing techniques and the construction of image-processing algorithms to answer ecological questions about abundance and population change. This, coupled with ecological knowledge from my co-authors, has meant that I have been able to make a significant contribution to the field, which has, and will in future, enable more robust estimates of resilience to climate change and enable more accurate assessment of harvesting quotas for ecosystem-based management of Southern Ocean fisheries. Having now published a number of signature papers in the field I feel that I am in an excellent position to drive forward the science to new species and subjects in and beyond Antarctica.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available