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EARTH SCIENCE > BIOSPHERE > ECOLOGICAL DYNAMICS > SPECIES/POPULATION INTERACTIONS > SURVIVAL RATES

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  • The dataset comprises records of crossings by Adelie penguins of a weighbridge and gateway established on Bechervaise Island. The weighbridge and gateway are positioned so that most or all of the penguins breeding in a set of sub-colonies on the island cross the weighbridge when they leave the colony to forage and when they return from foraging. The gateway records the time of each crossing, the dynamic weight of the penguin as it crosses, and the identity of penguins that have been sub-cutaneously tagged. The weighbridge and gateway operate continuously throughout the austral breeding season. The data are currently in an unprocessed form.

  • A systematic search for banded Antarctic petrels, Southern fulmars, Cape petrels and Skuas was conducted at Hop Island in the Rauer Group during the 2015/16 field season. Areas on Hop Island where banding had taken place previously were searched for banded birds. The data documents two resights that were made and an opportunistic resight on Gardner Island near Davis. Please refer to the Seabird Conservation Team Data Sharing Policy for use, acknowledgement and availability of data prior to downloading data.

  • This is a scanned copy of the Vertebrate Ecologists report from Davis Station, 1987. The report was written by Michael Whitehead. The report covers: Elephant Seals - Census and tagging program Weddell Seals - Adult resight and pup tagging programs Adelie Penguins - Monitoring population size (aerial photographic survey, and ground survey/pattern of occupation of colonies) - Diet study - Survival/mortality study of eggs and chicks - Seasonal fluctuation in adult condition and chick growth - Energetics studies - Swimming behaviour - Food availability Emperor Penguins - Diet study - Amanda Bay census Seabird studies - Southern Giant Petrel censusing and banding - Rauer Island seabirds (reference breeding group counts/banding and 1987/88 Rauers program)

  • The data are contained in a number of log books in hand written form (now scanned onto CD ROM. They were gathered according to a protocol updated annually by the Principal Investigator, DR Robert Carrick (now deceased). Details are contained in the paper Carrick R (1972) Population ecology of the Australian black-backed magpie, royal penguin, and silver gull. in: Population ecology of migratory birds - A symposium. US Dept of the Interior, Fish and wildlife service. Wildlife Research Report 2. pp 41-99. The only other information on the Royal penguin population to come from these investigations is the PhD Thesis of G.T. Smith, Studies on the behaviour and reproduction of the Royal penguin Eudyptes chrysolophus schlegeli. Australian National University April 1970. The log books contain a vast array of observations on the Royal penguin. Major observations/studies include banding of chicks and adults, breeding chronology, egg laying, breeding success, arrival weights, movements within and between colonies. The protocols for the collection of the data are missing although some instructions and notes are included in the volumes. Some data have also been entered into an excel spreadsheet.

  • Metadata record for data from ASAC Project 419 See the link below for public details on this project. From the abstracts of some of the referenced papers: The population size and breeding success of Emperor Penguins (Aptenodytes forsteri) at the Auster and Taylor Glacier colonies were estimated during the 1988 breeding season. At Auster a total of 10963 pairs produced about 6350 fledglings for a breeding success of 58%. At Taylor Glacier about 2900 pairs raised 1774 fledglings for a breeding success of 61%. Fledglings left Taylor Glacier over a period of 33 days at a mean mass of 10.56kg. The accuracy of the tritiated water (HTO) and sodium-22 (22Na) turnover methods as estimators of dietary water and sodium intake was evaluated in emperor penguins fed separate diets of squid and fish. Emperor penguins assimilated 76.2% and 81.8% of available energy in the squid and fish diets, respectively. Both isotopes had equilibrated with body water and exchangeable sodium pools by 2h after intramuscular injection. The tritium method yielded reliable results after blood isotope levels had declined by 35%. On average the tritium method underestimated water intake by 2.9%, with a range of -10.3% to +11.1%. The 22Na method underestimated Na intake on average by 15.9% with the errors among individuals ranging from -37.2% to -1.8%. Discrepancies with 22Na turnover were significantly greater with the squid diet than the fish diet. The results confirm the reliability of the tritium method as an estimator of food consumption by free-living emperor penguins (provided seawater and freshwater ingestion is known) and support the adoption of the 22Na method to derive an approximation of seawater of seawater intake by tritiated emperor penguin chicks and by tritiated adults on foraging trips of short duration. The diet composition of Emperor Penguin Aptenodytes forsteri chicks was examined at Auster and Taylor Glacier colonies, near Australia's Mawson station, Antarctica, between hatching in mid-winter and fledging in mid-summer by 'water-offloading' adults. Chicks at both colonies were fed a similar suite of prey species. Crustaceans occurred in 82% of stomach samples at Auster and 87% of stomachs at Taylor Glacier and were heavily digested; their contribution to food mass could not be quantified. Fish, primarily bentho-pelagic species, accounted for 52% by number and 55% by mass of chick diet at Auster, and squid formed the remainder. At Taylor Glacier the corresponding values were 27% by number and 31% by mass of fish and 73% by number and 69% by mass of squid. of the 33 species or taxa identified, the fish Trematous eulepidotus and the squid Psychroteuthis glacialis and Alluroteuthis antarcticus accounted for 64% and 74% of the diets by mass at Auster and Taylor Glacier, res pectively. The sizes of fish varied temporally but not in a linear manner from winter to summer. Adult penguins captured fish ranging in length from 60 mm (Pleuragramma antarcticum) to 250 mm (T. eulepidotus) and squid (P. glacialis) from 19 to 280 mm in mantle length. The length-frequency distribution of P. glacialis showed seasonal variation, with the size of squid increasing from winter to summer. The energy density of chick diet mix increased significantly prior to 'fledging'.

  • This is a copy of a scanned document which contains a report, as well as tabulated data compiled by K. Brown on Sea Elephants (Elephant Seals) at Heard Island in 1951. The data are biological in nature, and deal with: Breeding Season 1951 Formation of the Harems Arrival of the Bulls Arrival of the Cows Birth of the Pups Lactation Moult Pup Mortality Fertilisation of the Cows Break up of the Harems Arrival of the Adolescents

  • From the abstract of some of the papers: It has been suggested that increased springtime UVB radiation caused by stratospheric ozone depletion is likely to reduce primary production and induce changes in the species composition of Antarctic marine phytoplankton. Experiments conducted at Arthur Harbour in the Antarctic Peninsula revealed a reduction in primary productivity at both ambient and increased levels of UVB. Laboratory studies have shown that most species in culture are sensitive to high UVB levels, although the level at which either growth or photosynthesis is inhibited is variable. Stratospheric ozone depletion, with resultant increased springtime UVB irradiance, has been occurring with increasing severity since the late 1970's. Thus the phytoplankton community has already experienced about 20 years' exposure to increasing levels of UVB radiation. Here we present analyses of diatom assemblages from high-resolution stratigraphic sequences from anoxic basins in fjords of the Vestfold HIlls, Antarctica. We find that compositional changes in the diatom component of the phytoplankton community over the past 20 years cannot be distinguished from long-term natural variability, although there is some indication of a decline in the production of some sea-ice diatoms. We anticipate that our results are applicable to other Antarctic coastal regions, where thick ice cover and the timing of the phytoplankton bloom protect the phytoplankton from the effects of increased UVB radiation. Growth rate, survival, and stimulation of the production of UV-B (280 to 320 nm) absorbing compounds were investigated in cultures of five commonly occurring Antarctic marine diatoms exposed to a range of UV-B irradiances. Experimental UV-B exposures ranged from 20 to 650% of the measured peak surface irradiance at an Antarctic coastal site (0.533 J per square metre per second). The five diatom species (Nitzschia lecointei, Proboscia alata, P. inermis, Thalassiosira tumida and Stellarima microtrias) appear capable of surviving two to four times this irradiance. In contrast to Phaeocystis cf. pouchetti, another major component of the Antarctic phytoplankton, the concentrations of pigments with discrete UV absorption peaks in diatoms were low and did not change significantly under increasing UV-B irradiance. Absorbance of UV-B by cells from which pigments had been extracted commonly exceeded that of the pigments themselves. Most of this absorbance was due to oxidisable cell contents, with the frustule providing the remainder. Survival of diatoms did not correlate with absorption by either pigments, frustules or oxidisable cell contents, indicating that their survival under elevated UV-B irradiances results from processes other than screening mechanisms. Springtime UV-B levels have been increasing in Antarctic marine ecosystems since the 1970's. Effects on natural phytoplankton and sea-ice algal communities, however, remain unresolved. At the Marginal Ice Edge Zone, enhanced springtime UV-B levels coincide with a shallow, stratified water column and a major phytoplankton bloom. In these areas it is possible that phytoplankton growth and survival is adversely impacted by enhanced UV-B. In coastal areas, however, the sea ice, which attenuates most of the UV-B before it reaches the water column, remains until December/January, by which time UV-B levels have returned to long-term seasonal averages. Phytoplankton from these areas are unlikely to show long-term changes resulting from the hole in the ozone layer. Fjords of the Vestfold Hills, eastern Antarctica, have anoxic basins which contain high-resolution, unbioturbated sedimentary sequences. Diatom assemblages from these sequences reflect the diatom component of the phytoplankton and sea-ice algal assemblages at the time of deposition. Twenty-year records from these sequences show no consistent record of change in species composition, diversity or species richness. Six-hundred-year records from the same area also show changes in species abundance greater than those seen in the last 20 years. From these records it can be seen that recent changes in diatom abundances generally fall within the limits of natural variability and there is little evidence of recent changes that might be associated with UV-B-induced change.

  • This dataset contains the results from studies of the Elephant Seal (Mirounga leonina) at Macquarie Island. Results from branding surveys and photographs from 1985 onwards are reported. Numbers, life stage, sex, moult stage and migration patterns have been reported. Currently some 2000 pups a year are branded and the dataset includes birth dates, weights at birth and weaning and at 6, 12 and 18 months. This work was completed as part of ASAC (AAS) project 2265 (ASAC_2265). Objectives: 1. To prepare research papers, from the extensive southern elephant seal dataset, that deal with key demographic parameters of the population such as size, age specific survivorship, fecundity, recruitment into the breeding population, age specific growth rates, and intrinsic rate of change of the population. In addition, later papers will investigate interannual variability in these parameters, how these relate to changing environmental conditions, and the effects of this on long term population fluctuations. 2. To analyse and compare stable isotope ratios in the facial vibrissae of the seals and the hard parts of their prey to determine the geographical positions of the major foraging grounds of the seals. The isotope values will also allow the food webs, that support the seals, to be better defined. 3. To measure the growth rates of elephant seal vibrissae so that changing isotope values, related to the prey and foraging areas, can be referred to particular foraging periods. Elephant seals characteristically have two separate periods of foraging: one in summer and one in winter. The positions of these episodes on a vibrissa can be identified once the growth rates of vibrissae are known. Taken from the progress report for the 2009-2010 season: Progress against objectives: 1. One paper published from the elephant seal dataset. Two papers also published during 2009/10 using data collected opportunistically during the life of this project. 2. PhD student Andrea Walters continues to analyse the results of the whisker analyses. She has presented some of her results at the AMSA 2009 marine connectivity conference in Adelaide. An honours student has been engaged (start date March 2010) to analyse the squid component of the seals' diet. 3. John van den Hoff spent the early summer at Macquarie Island finalising the collection of the demographic data. 2154 tag/brand resights were recorded. Collection of the data has continued on the island by Chris Oosthuizen, Ben Arthur and Iain Field since John returned to Australia. When those field workers return data collection will cease.

  • Metadata record for data from ASAC Project 229 See the link below for public details on this project. From the abstracts of some of the referenced papers: In January 1985 a net sampling survey was carried out on the distribution and abundance of euphausiid larvae in the Prydz Bay region. Euphausia superba occurred in low abundance, probably due to sampling preceding the main spawning period. Thysanoessa macrura occurred throughout the study area in consistently high abundance. Euphausia crystallorophias as marginally more abundant within its restricted range. Distinct north-south variations in larval age and development stages of T. macrura were observed indicating regional differences in spawning. Euphausia frigida was mainly confined to the upper 200 m of the Antarctic Circumpolar Current. Larvae originating on the shelf moved rapidly west in the East Wind drift. E. crystallorophias had the same westward dispersion, but some larvae appeared to return eastward via the Prydz Bay Gyre and remain in the region. The data indicate that most E. superba larvae, providing they survive injurious cold temperature and food deprivation, will leave the area, suggests that Prydz Bay krill may not be a self sustaining stock. ##### This paper presents results of net sampling carried out in four marine science cruises between 1981 and 1985, in the Prydz Bay region of Antarctica by the Australian Antarctic Division. Krill exhibited a patchy distribution and overall low abundance. The majority of sampling sites in January 1985 returned no post-larval krill or densities of less than 1 individual per 1000 cubic metres. The estimated mean abundance of E. superba in January 1985 was 6 indivduals or 2 g (wet wt.) per 1000 cubic metres integrated for the upper 200m of the water column which represented 3.4% of the total zooplankton biomass. No more than five years-groups, including the larvae, were observed in Prydz Bay, with mean lengths of groups 1+, 2+, 3+ and 4+ being 24, 38, 46 and 53 mm (standard 1), respectively in the middle of January. A high proportion of naupliar stages observed in January 1985 indicated that spawning in Prydz Bay begins in January and examination of adult maturation showed that the spawning continues at least to March. ##### Sixty female Antarctic krill (Euphausia superba Dana) spawned in shipboard experiments and the interval between egg-laying and ecdysis was noted. The number of eggs laid per female ranged from 263-3662, most females produced only one batch of eggs before moulting, and the post spawn ovaries of all females contained few, if any, mature oocytes. As reported in other studies, the total number of eggs produced per female was not well correlated with body size. Females appeared to spawn at all times during the moulting cycle and although no diurnal rhythm in spawning was observed, moulting occurred mainly at night-time despite the animals being kept in near-constant darkness. No evidence of synchronous moulting was detected. ##### Data from this project were collected on five Antarctic voyages: HIMS - Heard Island Marine Science - 1990-05-04 - 1990-07-01 AAMBER II - Australian Antarctic Marine Biological Ecosystem Research II - 1991-01-3 - 1991-03-19 FISHOG - Fish and Oceanography - 1992-01-09 - 1992-03-27 KROCK - Krill and Rocks - 1993-01-05 - 1993-03-09 BROKE - Baseline Research on Oceanography, Krill and the Environment - 1996-01-02 - 1996-03-31 All data are available in the download file.

  • The objectives for this project were: The project aims to quantify the patterns of dispersal and survival of newly weaned southern elephant seal pups to provide information on position at sea and foraging behaviour of the pups once they leave Macquarie Island, and to examine how this is related to position at sea and foraging behaviour in the second year. This information will be used to test the hypothesis that first year survival is a consequence of the young animals exploiting different foraging grounds to adults, and that fishing activity on the Campbell Plateau may be a contributing factor. In addition, stable isotope analysis and fatty acid signature analysis will be used to examine differences in foraging behaviour from animals while they are at sea. The raw data from this project is added to the long term database described by the metadata records 'Macquarie Island Elephant Seal Populations 1950-1965', and 'Macquarie Island Elephant Seal Populations 1985 Onwards'. This database has been taken offline, however. A snapshot of the database was taken in January, 1995, and is linked at the provided URL. For access, contact the Australian Antarctic Data Centre. A number of papers have been produced from this project. Some of these papers are included in the reference section below. The data collected for the database is as follows: Seal Number Status (new or resight) Date Location Age Class Status (cow, beachmaster, pregnant cow, dead etc) Sex Weight Length Size Back Fat Flipper Body Water Time Depth Recorder