It is important to know the age of wild animals if we are to understand some aspects of a species' life history and ecology. Body structures that are used to determine age can also yield information on an animal's general health and reproductive history, and the influence of environmental factors on growth, health and reproduction of a population. The techniques used for estimating the age of marine mammals using bone and teeth were first developed in the 1950s and are continuing to be refined and verified for a increasing number of species.
Museum collections have considerable potential for studying animal biology. The marine mammal collection at the South Australian Museum is the largest and most comprehensive in Australia. It includes many teeth collected from whales, dolphins, porpoises, seals, sea lions and dugongs. These are the raw materials needed for studying the age of the marine mammals that live in the Southern Ocean. This collection and the need for a national facility to study age provided the impetus to establish a Marine Mammal Aging Facility in 2007, with financial assistance from the Australian Marine Mammal Centre (Australian Antarctic Division, Hobart). The Facility is managed by Dr Catherine Kemper (Curator and Senior Researcher, SA Museum) with the assistance of Dr Karen Evans (CSIRO/University of Tasmania), Dr Jane McKenzie (marine mammal consultant, Adelaide) and Dr Rebecca McIntosh (Honorary Associate, La Trobe University). These researchers have considerable experience in estimating the age of marine mammals and publish scientific research in that field.
The objectives of the Facility are to:
- provide training facilities for researchers new to the field
- provide a centralised facility housing high-quality equipment for the preparation and analyses of samples for projects that do not have funds or personnel available for training
- increase the pool of qualified readers for age estimation and validation
- provide readily accessible and long-term storage of processed material for future access and reference by the scientific community.
An intensive workshop was held at the Facility in 2007 and there are plans to organise another in 2012 or 2013. Several students, including three from Università Politecnica Delle Marche, Ancona, Italy, have been trained at the laboratory and other researchers have made use of the facility. It currently supports research undertaken by the Museum investigating age and life history of bottlenose and common dolphins in South Australian waters.
A comprehensive manual for marine mammal age determination, aimed at both new and experienced researchers, has been produced by the Facility and is available for download.
The manual includes:
- a history and background of the techniques
- steps for preparing teeth for thin-sectioning and acid-etching
- methods for estimating ages from prepared tooth samples
- a comprehensive bibliography on marine mammal age determination.
The following contract services are available upon request to Catherine Kemper
- hire of laboratory space and equipment/consumables for use by an experienced researcher for the preparation and estimation of marine mammal ages using teeth
- training of inexperienced students/researchers in techniques of age estimation of marine mammals using teeth
- preparation of decalcified, stained, thin-sections of marine mammal teeth for age determination
- preparation of acid-etched medium to large-sized marine mammal teeth for age determination
- provision of age estimates based on either decalcified, stained, thin-sections or acid-etched marine mammal teeth