Aquafin CRC - Atlantic Salmon Aquaculture Subprogram: development of selective enrichment culture-polymerase chain reaction (SEC-PCR) for the detection of bacterial pathogens in covertly infected farmed salmonid fish
Application of molecular genetics to the Australian abalone fisheries: forensic protocols for species identification and blacklip stock structure
Evaluating the effectiveness of marine protected areas as a fisheries management tool
Workshop on post settlement processes affecting the southern rock lobster (Jasus edwardsii) in southern Australia
Final report
Research into the southern rock lobster in Australia has concentrated on the catching sector (primarily commercial) with limited research being undertaken on the post-settlement and juvenile stages. To maximise the outputs of investigating these stages, while at the same time minimising costs, a comprehensive understanding of the latest developments in the field is necessary. It was considered that this was best served by holding a workshop to review existing research, facilitate discussion amongst those involved in the area of research, and plan future research in relation to southern rock lobster.
Key issues for the workshop were considered to be: (1) the relevance of juvenile research to catch prediction; (2) growth information for stock assessment modelling; (3) impact and management of puerulus extraction for aquaculture; and (4) contribution to broader management in relation to conservation of egg production vs perceptions of stability of recruitment due to density dependent mortality.
Participants at the workshop reviewed the current status of knowledge in post-settlement rock lobster research, including methods used to research these cryptic stages. Participants included key industry, government and research partners and their discussions resulted in a collaborative research plan aimed at investigating post-settlement processes. Key areas were documenting macro-habitat requirements, growth rates, mortality estimates of juveniles and puerulus, identifying predators and competitors. The over-riding goal was considered to be the identification of
“bottlenecks”.
"Bottlenecks" are phases during development where a factor affecting abundance decouples the link between the abundance of a size class for that proceeding it. For instance, shelter limitation for a particular size class is a bottleneck as this would result in reduced inter-annual variation in the abundance of larger animals. The research proposed from this workshop would evaluate bottlenecks by identifying the stages and factors during juvenile development where density dependent mortality influences abundance. These factors reduce the signal between puerulus abundance indices to fishery recruitment and are important in understanding the effect of puerulus removal or habitat changes.
International participation at the workshop (from NZ, Japan & USA) was helpful in fostering links in this field of research.
Keywords: Southern rock lobster, resource sustainability, recruitment, aquaculture, mortality, density dependence.
9th International Conference on Harmful Algal Blooms, 7-11 February 2000, Hobart
Starting in the mid 1980s, Australia has experienced an increased public
awareness of harmful algal blooms, especially their suspected involvement
in causing fish kills and feared public health risks following consumption
of contaminated seafood products and drinking water supplies. If not
adequately monitored and managed, the economic impacts on Australia's
developing aquaculture industry and on both domestic and export markets
could be devastating. An example of the first problem is the 1989 bloom
event by the golden-brown flagellate Heterosigma akashiwo in Big Glory
Bay, New Zealand, which killed NZ$ 12 million worth of cage-reared chinook
salmon. An example of the second problem is the 1993 New Zealand outbreak
of neurotoxic shellfish poisoning by the dinoflagellate Gymnodinium cf.
breve (NSP; 180 illnesses, no deaths) which led to export losses of NZ $
4.5 million in the first quarter of 1993 and a 25% decrease in domestic
shellfish demand . Similarly, positive test results are now available from
Australian shellfish products for paralytic shellfish poisons (NSW,
TAS,VIC,SA), diarrhetic shellfish poisons (TAS), amnesic shellfish poisons
(VIC) , neurotoxic shellfish poisons (VIC) and cyanobacterial peptide
toxins (WA). While algal biotoxins only in extreme cases lead to human
fatalities, it is the so-called "halo"-effect of bad publicity resulting
from a few human poisonings that can devastate aquaculture industries.
Compared to our neighbour New Zealand, which spends $3.2 M per year in
biotoxin monitoring efforts (most comes from the Ministry of Health, with
industry providing $750,000 per year via an industry levy), Australian
efforts in this area of quality assurance and environmental protection of
aquaculture operations are unsatisfactory.
Final report
The FRDC sponsored 9th International Conference on Harmful Algal Blooms held in Hobart, Tasmania, from 7-11 February 2000, was a resounding success. It was the largest conference on this topic (526 participants from 47 countries) ever held anywhere in the world. A total of 130 talks and 308 poster presentations were given. The conference broke important new ground by dedicating a special session to Algal Bloom Monitoring, Management & Mitigation. Special sessions were also dedicated to Impacts on Shellfish Aquaculture and Impacts on Finfish Aquaculture. Two FRDC representatives (Peter Lee and Alex Wells) attended, and as a special service to the Tasmanian finfish aquaculture industry US expert Dr Jack Rensel gave a keynote conference address, a special satellite seminar for fishfarmers and government staff, as well as met with 4 fish farming companies on site. US experts Prof. Sandra Shumway and Dr Monica Bricelj visited several shellfish aquaculture operations. A public forum on "Harmful Algal Blooms: Impacts on Health, Environment & Economy" was scheduled in association with the conference. The publication outputs from this meeting include a 518 pages Conference Proceedings Volume (to be published through the Intergovernmental Oceanographic Commission of UNESCO) and a special issue of the international journal Phycologia (vol. 40(3)) both to appear in 2001.
Keywords: Harmful Algal Blooms; Shellfish Biotoxins; Aquaculture Finfish Kills