PILCHARD (Sardinops Sagax) MORTALITY EVENTS in AUSTRALIA and RELATED WORLD EVENTS
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PILCHARD (Sardinops sagax) MORTALITY EVENTS IN AUSTRALIA AND RELATED WORLD EVENTS FRDC Project 99/227 Alexandra C. Gaut PILCHARD (Sardinops sagax) MORTALITY EVENTS IN AUSTRALIA AND RELATED WORLD EVENTS ________________________________ FRDC Project 99/227 Alexandra C. Gaut ISBN 0 759 01316 0 PREFACE AND DISCLAIMER As part of the investigations into the 1995 and 1998-99 pilchard mortality events in southern Australian waters, Australia’s Consultative Committee on Emergency Animal Diseases (CCEAD) endorsed a national strategic research program developed by its Joint Pilchard Scientific Working Group (JPSWG) in October 1998. In addition to the research projects, JPSWG identified the need for a comprehensive report on the mortality events. In February 1999, PIRSA Fisheries submitted a project proposal to the Fisheries Research and Development Corporation to obtain funds to produce such a report. Funding was provided in October 1999. A consultant was appointed in February 2000, and a preliminary draft of the report was submitted to JPSWG in August 2000. The report was compiled by the author on behalf of PIRSA Fisheries but represents the collective views of members of the JPSWG. All members of the committee made substantial contributions to the report. Throughout their deliberations, members of the JPSWG had utmost respect for each other’s views, but there was not always unanimous agreement on all matters. Individual members or organisations represented do not necessarily agree with each of the statements and interpretations made in the report. JPSWG submitted the draft final report to CCEAD in October 2000. CCEAD members endorsed the report, however, substantial comments on the contents were received from both South Australia Animal Health and from Fisheries Western Australia. The author considered all submissions when preparing the final version, but incorporation of all comments from all reviewers was not possible, especially where views expressed by different reviewers were diametrically opposed. In particular, some of the changes suggested by SA Animal Health and Fisheries WA were not incorporated. Advice regarding the nature of these suggested changes can be obtained from the organisations. PIRSA Fisheries and the JPSWG have taken all reasonable steps to ensure that the information contained in the report is accurate at the time of production. Readers should ensure that they make appropriate inquiries to determine whether new information is available. 1 TABLE OF CONTENTS PREFACE AND DISCLAIMER................................................................................................................................ 1 1 ACRONYMS AND ABBREVIATIONS................................................................................................6 2 NON-TECHNICAL SUMMARY............................................................................................................8 3 INTRODUCTION .....................................................................................................................................10 3.1 BACKGROUND.......................................................................................................................................... 10 3.2 NEED.......................................................................................................................................................... 10 3.3 OBJECTIVES.............................................................................................................................................. 11 4 MASS MORTALITY EVENTS IN MARINE FISHES ..................................................................13 4.1 AUSTRALIA AND NEW ZEALAND PRIOR TO 1995................................................................................ 13 4.1.1 Australia........................................................................................................................................13 4.1.2 New Zealand.................................................................................................................................14 4.2 OVERSEAS................................................................................................................................................. 15 4.3 DISEASES AND PARASITES OF PILCHARDS............................................................................................ 16 4.3.1 Diseases .........................................................................................................................................16 4.3.2 Parasites........................................................................................................................................17 4.4 HERPESVIRUSES OF OTHER AQUATIC ORGANISMS.............................................................................. 17 4.4.1 Fish .................................................................................................................................................18 4.4.2 Reptiles...........................................................................................................................................19 4.4.3 Marine mammals..........................................................................................................................19 4.4.4 Bivalves..........................................................................................................................................20 4.4.5 Crustaceans...................................................................................................................................20 4.4.6 Phytoplankton...............................................................................................................................20 5 1995 TECHNICAL OVERVIEW ..........................................................................................................24 5.1 INTRODUCTION........................................................................................................................................ 24 5.2 TECHNICAL INFORMATION..................................................................................................................... 25 5.2.1 Histopathology..............................................................................................................................25 5.2.1.1 Gills ............................................................................................................................................ 25 5.2.1.2 Other tissues............................................................................................................................... 29 5.2.2 Cell culture....................................................................................................................................29 5.2.3 Polymerase Chain Reaction Analysis.......................................................................................29 5.2.4 Electron Microscopy....................................................................................................................30 5.2.5 Protozoology.................................................................................................................................30 5.2.6 Phytoplankton and biotoxins......................................................................................................31 5.2.7 Environmental Data.....................................................................................................................31 5.3 TRANSMISSION TRIALS........................................................................................................................... 33 5.4 IMPORTED PILCHARD SURVEY 1995-1996........................................................................................... 33 5.5 DISCUSSION.............................................................................................................................................. 34 6 1998 TECHNICAL OVERVIEW ..........................................................................................................35 6.1 INTRODUCTION........................................................................................................................................ 35 6.2 TECHNICAL INFORMATION..................................................................................................................... 35 6.2.1 Histopathology..............................................................................................................................35 6.2.1.1 Gills ............................................................................................................................................ 35 6.2.1.2 Other tissues............................................................................................................................... 36 6.2.2 Electron Microscopy....................................................................................................................36 6.2.3 Pilchard cell culture....................................................................................................................37 6.2.4 Polymerase Chain Reaction (PCR) Analysis ..........................................................................38 6.2.5 Phytoplankton and Biotoxins.....................................................................................................39 6.2.6 Environmental Data.....................................................................................................................39 6.3 WA TRANSMISSION STUDIES................................................................................................................