Monitoring abalone juvenile abundance following removal of Centrostephanus and translocation
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
Project products
Developing a cost-effective and novel fisheries-independent monitoring program to inform scalefish fisheries management
Target species of Tasmanian scalefish fisheries (TSF) remain difficult to assess and manage due to the wide range of species (> 20 species) and variety of both commercial and recreational fisheries methods. TSF are currently assessed using commercial catch and effort data as well as age and length information. However, some key TSF species landings are increasingly greater in the recreational sector, with a comparatively low commercial catch. Therefore, due to the absence of regular and robust CPUE data, innovative fishery independent data collection programs are required to routinely monitor TSF species and provide adequate data for stock assessment models. This project will review and collate data from previous studies to design and test strategic and cost-effective novel fishery-independent survey methods that collect population dynamics data for a suite of key scalefish fisheries species, across both environmental and fishing intensity gradients in Tasmania. Outcomes will improve stock assessment methods by providing new and additional data for data-poor and undefined species, and, if proven cost-effective, establish an ongoing, long-term fishery-independent monitoring program to enhance the sustainability of TSF. We will collate historical data on Tasmanian scalefish abundance, biomass, distribution, and length-frequencies collected in previous research projects and collect and compare new data to fill current knowledge gaps about localised population depletion and population dynamics across different habitats. Many of the popular commercial and recreational scalefish fisheries are increasingly of concern, with southern sand flathead, southern garfish, and bastard and striped trumpeters all assessed as depleted in the most recent (2020/21) Tasmanian stock assessment (Fraser et al 2022), while others (such as flounder - Pleuronectidae family, longsnout boarfish, and barracouta) were assessed as undefined due to lack of available data for these species. Our results will better inform data-poor stock assessment approaches and will have implications for fisheries managers making critical management decisions for depleted, depleting, and undefined Tasmanian scalefish fisheries species.