Environmental determinants of fecundity and pup growth in fur seals

This indicator is no longer maintained, and is considered OBSOLETE.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 condition of a system.

This indicator is one of: CONDITION

RATIONALE FOR INDICATOR SELECTION

A highly negative correlation has been detected between sea surface temperatures in the vicinity of Macquarie Island and fur seal fecundity and pup growth. A dataset of over ten years has shown that autumn sea-surface temperatures are highly negatively correlated with female fecundity in the following breeding season.

Rather than the reproductive success in terms of fecundity and pup growth being seen simply as a correlate of SST and presumably ocean productivity, the measure is much more than this. What the dataset from the Macquarie Island fur seal populations is rather more unique, in that they indicate how environmental variability effects the reproductive success of animals at annual and lifetime scales. This is especially important as we can now show what impacts environmental/climatic phenomena such as the Antarctic Circumpolar Wave, and global warming will have on fur seals, and how changes in the environment may impact on the viability of populations. In this situation, the data clearly suggest that warmer ocean temperatures significantly effect the reproductive success of fur seals. Sustained warmer temperatures would therefore impose demographic constraints on populations.

DESIGN AND STRATEGY FOR INDICATOR MONITORING PROGRAM

Spatial scale: SST data are obtained from a 1 degree square just north of the island that represents the region in which most females obtain food throughout their lactation period.

Frequency: Data on the reproductive success of fur seals is to be collected annually.

Measurement technique: Each breeding season (November-January), the reproductive success of tagged females is monitored, including their pupping success, and the growth rates of their pups.

RESEARCH ISSUES

LINKS TO OTHER INDICATORS

Identification info

Alternate title: Environmental determinants of fecundity and pup growth in fur seals

Date (Publication): 2001-06-26

Edition: 1

Citation identifier

Dataset DOI

Title: Information and documentation - Digital object identifier system

Date (Publication): 2012-04-23

Citation identifier: ISO 26324:2012

Citation identifier: doi:10.26179/5d2e8725bb2d5

Originator

Goldsworthy, S.

Publisher

Australian Antarctic Data Centre

Principal investigator

GOLDSWORTHY, SIMON

South Australia

Australia

Name: CAASM Metadata

Website: https://data.aad.gov.au/metadata/records/SOE_fur_seals

Status: Completed

Custodian

AU/AADC > Australian Antarctic Data Centre, Australia - AADC, DATA OFFICER (DATA CENTER CONTACT)

Australian Antarctic Division

203 Channel Highway

Kingston

Tasmania

7050

Australia

+61 3 6232 3244

+61 3 6232 3351 (facsimile)

Topic category

Biota
Oceans

Extent