Title

Dugong strandings: causes of mortality

Objectives

1. To maintain a database for dugong strandings in Queensland that integrates the records from all regions and agencies.
2. To conduct a pathological investigation of suitable dugong carcasses to determine causes of death.

Relevance

A knowledge of the distribution (geographic and temporal), frequency and sources of dugong mortality is necessary for guiding effective and timely management responses.

Identification of the cause of death is not always obvious to the non specialist. Pathological examination of suitable carcasses by a veterinary specialist is necessary to provide knowledge on the range of health issues impacting our dugongs as well as to provide clear evidence of mortality from anthropogenic sources.

Feasibility

This project is achievable. A preliminary state-wide database already exists and receives records from a wide variety of sources. Preliminary investigation of dugong pathology has been in progress since 1997 as a collaborative project between Queensland Parks and Wildlife Service (QPWS) and the Department of Primary Industries & Fisheries (DPI) staff in Rockhampton.

The first findings from the pathology research have been published (Hill, B.D., Fraser, I.R. and Prior, H.C. 1997, Cryptosporidium infection in the dugong (Dugong dugong), Australian Veterinary Journal, 75(9)). A second manuscript is in advanced preparation: Hill, B.D., Byron, G.T. and Cook, D. (in prep). Severe tracheaitas and broncho-pneumonia in a juvenile dugong caused by infection of Cochleotrema indicum.

Methodology

Regional reports on stranded dugongs will be validated and collated into a state-wide relational database. Currently the database is maintained by the Environmental Protection Agency, Brisbane (fax: 07 3227 6386) and is compatible for analysis with standard GIS software. It integrates information recorded on site at stranding locations with results from clinical and pathological studies. The database will be made available to regional offices and other users via the Departmental computing services.

A training module will be developed for relevant personnel in post mortem examination of dugongs, specimen collection and storage and transport for pathological investigations.

Training will be undertaken with QPWS and Great Barrier Reef Marine Park Authority staff in regional locations and autopsy kits and protocols will be provided to ensure optimum pathological specimens.

Post mortems will be conducted on freshly dead and moribund dugongs along the coastline from Cairns to the Gold Coast with particular emphasis on:

• gross and histopathological examination of a standard range of organ tissue specimens, including the brain; and

• haematological and biochemical examination of blood and fresh tissue specimens.

Parasitological and protozoological examination of faecal specimens will be undertaken where warranted.

Results of autopsies will be immediately available including feedback to agencies and staff involved. Summary reports will be prepared annually. Significant scientific results will be submitted for publication within peer reviewed journals.

Approximate cost

Database development and maintenance $ 5 000

Pathology $17 000

Total $22 000 p.a.

Time required

Two years

Project to be reviewed with a view to long-term continuance at the end of the second year.