LEOPARD SEALS
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This database is a compendium of histories of known age seals (Weddell and Southern elephant) from observations across the Southern Ocean but focussed on Macquarie Island, Marion Island, Heard Island, Mawson and the Vestfold Hills. At Macquarie Island 1000 seals were weighed per annum between 1993-2003 at birth and individually marked with two plastic flipper tags in the inter-digital webbing of their hind flippers. These tagged seals were weighed again at weaning, when length, girth, fat depth, and flipper measurements were made. Three weeks after weaning 2000 seals were permanently and individually marked by hot-iron branding. Recaptures and re-weighings of these known aged individuals were used to calculate growth and age-specific survival of the seals. Similar data were collected from elephant seals between 1950 and 1965 when seals were individually marked by hot-iron branding. Mark-recapture data from these cohorts were used to assess the demography of the declining population. Length and mass data were also collected for these cohorts and were used, for the first time, to assess the growth of individual seals without killing them. At Marion Island all the elephant seals have been individually marked with two plastic flipper tags in their rear flippers. Recaptures of these seals were used to compare survival at Marion and Macquarie Islands. At Heard Island, seals were branded between 1949-1953. Seal length was measured in feet and inches. Recaptures of seals were made up until 1955, and growth and age-specific survival was calculated. Survival data from Heard Island were compared with concurrent data from Macquarie Island. The database was held by the Australian Antarctic Data Centre, but was taken offline due to maintenance problems. A snapshot of the database was taken in June 2018 and stored in an access database. This work was completed as part of ASAC project 90.
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2000/2001 season 31 quad based surveys were conducted along the pack-ice edge to identify where leopard seals could be accessed. 31 one hour aerial surveys were also conducted to identify the position and number of seals in the region. 36 boat based surveys were conducted to identify the size and sex of leopard seals, whether they were a resight and the possibility of sedating seals. There were a total of 23 leopard seal captures. Resights from the 1999/2000 season were made of 5 known seals. Samples were collected from a total of 19 known and 20 unknown leopards seals. Samples were also collected from 14 known weddell seals. All blood, fur, whisker, scat, and morphmetric measurements were collected. Three satellite tracking units were deployed following the moult on adult leopard seals, and one crittercam unit. 14 blood samples were taken from leopard seals, 13 blood samples from weddell seals. 6 blubber samples from leopard seals, 17 fur samples from leopard seals and 7 whiskers from leopard seals and 2 from weddell seals 32 scats from leopard seals, 50 urine and 30 scat samples from weddell seals. Voucher samples for stable isotope analysis from 2 weddell seals, 26 penguins and 64 fish were collected. Spatial movements and haul out data from 11 leopard seals has been analysed. The blood, skin muscle, whisker, fat and fur has been prepared for later analysis. 42 separate scats have been analysed to determine diet composition. The captive feeding trials have been performed using two captive leopard seals. For each seal the following tests have been conducted, biochemical analysis of fresh serum, manual packed cell volme and white cell counts and differential white cell counts from blood smears and all haematological analysis. The refinement of the anaesthetic protocol of Zolazepam/ Tiletamine in leopard seals has been continued and this combination appears to provide a deeper and more reliable level of immobilisation compared with other anaesthetic combinations to date. 2001/2002 season In the Prydz Bay area, 28 one-hour aerial surveys were conducted by Squirrel helicopter, 23 quad based surveys and 12 boat based surveys were conducted between latitudes 68 degrees 20'S and 68 degrees 40'S along the fast ice edge to identify the position and number of leopard seals in the region. 110 leopard seals were sighted overall and of those 5 were positively identified as resight animals, tagged during previous seasons. Five leopard seal capture procedures were performed and postmortem samples, blood fur, blubber, skin, whiskers, scats, urine and morphometric measurements were collected from two leopard seals. 6 urine and 15 scat samples collected from known and unknown leopard seals and 7 fur samples including 2 from resight animals tagged during the previous two seasons. Three Weddell seal capture procedures were performed and blood samples were collected from each seal. 125 weddell seal urine and 112 weddell seal scat samples were also collected. For stable isotope and signature fatty acid analysis, the following samples were collected as voucher samples; 1 weddell seal muscle sample, 3 adelie penguin muscle samples, 1 elephant seal whisker, muscle and skin sample, 73 Antarctic cod muscle samples, 23 ice fish and 20 krill. Foraging Information Scats collected from 20 seals and will be analysed for diet information. Stable isotope analysis involved fur, blood and whiskers collected from 35 animals. A key to the stable isotopes is provided in the download file. Fatty acid analysis involved collection of blubber from 35 animals. The fields in this dataset are: Spatial Data Seal Id: adult female Ptt tag number Date: date data collected Time: time data collected Location Class: ARGOS location classes 3 (0-150m), 2 (150-350m) and 1 (350-1000m). South: latitude decimal degrees East: longitude decimal degrees Amphipods ID = ID of seal from which scat sample collected Length = length of amphipod Wt = weight of amphipod Species = species of amphipod broken specimens = not whole specimens. Otolith data; No = number collected Species = species of fish identified from otolith Length/breadth/width = measurements of otolith in mm Eqn = calculation used to determine Standard length of fish from otolith size Mass = mass calculation of fish from otolith measurements Age and Length classes = size of mass of fish classified into groups Fatty acids Ret Time = retention time of individual fatty acid Area counts = TBA Area % = TBA LS Scat ID refers to the Identification number we gave to each seal. U refers to a unknown seal Date = date sample collected Sex = sex of seal Age = juvenile, sub adult or adult Seal = seal fur found in scat penguin = penguin remains found in scat and so on for each other column including fish, otolith, krill rocks, amphipod and seaweed. St weight refers to stomach weight.