Environmental determinants of fecundity and pup growth in fur seals

• Format: Dataset
• Language: unknown
• Published: Australian Ocean Data Network
• Subjects: biota; oceans; EARTH SCIENCE > OCEANS > OCEAN TEMPERATURE > SEA SURFACE TEMPERATURE; BIOLOGICAL CLASSIFICATION > ANIMALS/VERTEBRATES; ANIMALS/VERTEBRATES > MAMMALS; OCEAN CHEMISTRY > PIGMENTS > CHLOROPHYLL; BIOSPHERE > ECOLOGICAL DYNAMICS > SPECIES/POPULATION INTERACTIONS > POPULATION DYNAMICS; ECOSYSTEM FUNCTIONS > PRIMARY PRODUCTION; CLIMATE CHANGE; FECUNDITY; FUR SEALS; GLOBAL WARMING; VISUAL OBSERVATIONS; FIELD SURVEYS; AMD/AU; CEOS; AMD; OCEAN > SOUTHERN OCEAN; SOUTHERN OCEAN > MACQUARIE ISLAND; GEOGRAPHIC REGION > POLAR; Antarctic; Southern Ocean; Antarc*; Antarctic Fur Seals; Macquarie Island
• Online Access: https://researchdata.edu.au/environmental-determinants-fecundity-fur-seals/2821233

Progress Code: completed Statement: This indicator is now OBSOLETE. These data are no longer archived in this location, and are therefore not up-to-date. The Macquarie Island fur seal population consists of a marked, and largely known-aged population of fur seals. Each breeding season (November-January), the reproductive success of tagged females is monitored, including their pupping success, and the growth rates of their pups. Data from surface chlorophyll A concentration indicates that cooler sea-surface temperatures are associated with great local production in the vicinity of Macquarie Island. Cooler SSTs therefore are likely to be indicative of greater primary production and food availability for seal populations. Autumn months (March-May) are a period when female fur seals begin their active phase of placental gestation (after 4 months delayed implantation), it is also a period when the energy demand of suckling pups are greatest (end of lactation for Antarctic fur seals). As a period of nutritional stress, environmental variability in food abundance is most significant at this time. SST appears to provide a simple and reliable indicator of the state of the environment at this time, and in fact can be used as a window to predict pupping success 6-7 months in advance of the breeding season. Analysis of reproductive success and SST data over a number of years enables correlations between changes in regional oceanography and seal reproductive success to be assessed. This indicator is no longer maintained, and is considered OBSOLETE. INDICATOR DEFINITION The fecundity (pupping rates) of female fur seals and the growth rates of their pups relative to changes in sea surface temperatures (local primary production) in the vicinity of Macquarie Island. TYPE OF INDICATOR There are three types of indicators used in this report: 1.Describes the CONDITION of important elements of a system; 2.Show the extent of the major PRESSURES exerted on a system; 3.Determine RESPONSES to either condition or changes in the ...