3. Genetic Identification of Australian 3. Genetic Identification of Australian Marine Turtle Populations

3. Genetic Identification of Australian Marine Turtle Populations

Genetic sequencing is a tool for identifying different breeding populations. The word ‘population’ is used here to mean genetically distinct groups of marine turtles within a single species complex. Work to date has indicated that most species have distinct populations that can be managed as conservation units. The defining of these populations is still in progress and should be completed as a high priority.

The tracing of female lineages has allowed the identification of populations that nest in definable geographic areas and the identification of those populations where they mix in the feeding areas. As a tool it recognises shared populations and the need to manage populations regionally and in consultation with other jurisdictions. Moritz et.al. (1998b) have identified Australian populations that move in and out of the waters of Indonesia, Papua New Guinea and Pacific Island nations.

The analysis of currently undocumented marine turtle populations in Australia and those shared with other Asia/Pacific nations is required (Table 17). The completion of this analysis will allow the identification of further priorities for management and the capacity to identify the composition of populations in feeding grounds. This is particularly important in identifying Australian breeding populations that are subject to harvests elsewhere. Moritz et.al. (1998b) identified and prioritised the information gaps in order as:

 green turtle rookeries from east Arnhem Land, Sir Edward Pellew Islands and Indonesia;
 loggerhead turtle rookeries from southern New Caledonia;
 hawksbill turtle rookeries from the west Pacific; and
 flatback turtle rookeries from the Kimberley region, east Arnhem Land and Gulf of Carpentaria.

An important component of this work will be to sample and analyse resident feeding ground populations to determine the relative composition of the representative populations. This information will be added to monitoring and mortality data to determine the impact of mortality on each population. Ultimately it will assist in judging the security of Australian populations in relation to the levels of mortality at any time.

Table 17. Prescribed action to complete genetic analysis of Australian marine turtles