Tasmanian Salmon Research Articles

Large sardine resource discovered off south-eastern Australia: Potential risks, challenges and benefits of establishing a new fishery

This paper documents the discovery of a large sardine (Sardinops sagax) resource off South-eastern Australia. We use information from three ichthyoplankton surveys for jack mackerel to apply the Daily Egg Production Method (DEPM) to the South-eastern sardine stock. Mean daily egg production was estimated from survey data. Spawning area was estimated from the surveys and using a habitat suitability model to predict presence/absence of eggs in unsurveyed areas. Spawning biomass was calculated using adult parameters from the adjacent Southern stock. The spawning biomass in the area surveyed was 262,564 t (95% CI 125,670–326–438 t). Habitat modelling using a conservative threshold suggested that the total spawning biomass was 346,388 t (95% CI 143,936–548,840 t). These results suggest this stock has the capacity to sustain an annual catch of several tens of thousands of tonnes, which is considerably larger than the recent catch of < 2500 t. Our findings provide further evidence that opportunities exist to increase Australia’s fisheries production. Risks and challenges associated with establishing a new large-scale sardine fishery, including bycatch and ecological impacts, and opposition from conservation groups and recreational fishers are discussed. We also outline the potential socio-economic and environmental benefits, including the use of marine protein and oil from a sustainable local source with low environmental impacts as an input to the AU$1.3B Tasmanian salmon aquaculture industry. We emphasize the need to adopt a precautionary approach to developing a new fishery and the critical importance of conducting comprehensive surveys to confirm our findings and inform ongoing management.

Belly Up: How Corporate Interests Are Keeping an Unsustainable Tasmanian Aquaculture Afloat and Failing to Protect the Welfare of the Nonhuman Animals Affected

AbstractThe Tasmanian salmon industry has become one of the state's most profitable industries to date. Though production conditions notoriously lack transparency, there is a clear dependency on the mass production of complex nonhuman animals who are kept in inappropriate conditions and subject to harmful industry practices. This article explores why the Tasmanian Environmental Protection Agency recently approved the construction of the largest salmon hatchery in Australia, despite serious environmental sustainability and welfare concerns. It considers the likely impact of the new hatchery on the welfare of both the farmed nonhuman animals and the surrounding free-ranging life and advocates for industry improvements that are guided by considerations of nonhuman animal welfare and environmental sustainability.

Radical path transformation of the Norwegian and Tasmanian salmon farming industries

ABSTRACT This paper investigates the radicalness of industry path transformation in different geographical contexts by analysing the introduction of new technological trajectories within established industry paths. We use an analytical framework based on path dependence theory to conduct a comparative case study of the introduction of offshore farming technology in the salmon farming industry in both coastal Norway and Tasmania, Australia. We show that similar points of departure can lead to different path transformation radicalness. In each case, the transformation outcome will depend on the unique interplay between agency and regional structural components during windows of opportunity. The empirical analysis supports the importance of considering agency, regional structural components and global technology trends when investigating path transformation radicalness.

Benefits and detrimental effects of ocean warming for Tasmanian salmon aquaculture

Atlantic salmon (Salmo salar) is the main aquaculture species in Tasmania, Australia. This species is known to be sensitive to ocean temperature and has its own optimal temperature range for exceptional growth. As a hotspot of ocean warming, adaptation planning may be necessary for Tasmanian salmon aquaculture industries in coming years. In this study, we used high-resolution sea surface temperature (SST) satellite observations to investigate ocean temperature variability and trends in the southeastern Tasmania over the past 28 years, and their impacts on growth suitability for sea-farmed Atlantic salmon using a metric called optimal days. We found that long-term ocean warming in the region was evident but showed both positive and negative effects on optimal days. Winter warming would make salmon farms more suitable for salmon growth, while summer warming would make it too warm to grow optimally, which could lead to increased fish disease and even death. This seasonal difference also explained the year-to-year variability in the number of optimal days. Furthermore, spatial distributions of optimal day anomalies indicated that some farm regions were affected more than the others. Northern regions are becoming unsuitable for salmon aquaculture, while southern regions are still optimal for salmon growth in the next few decades. These findings demonstrate the complexity of consequences of global warming for salmon aquaculture industries, and can help stakeholders to develop a blue print for strategizing future farm development and climate change adaptation plans.

Perceiving Environmental Science, Risk and Industry Regulation in the Mediatised Vicious Cycles of the Tasmanian Salmon Aquaculture Industry

ABSTRACT This paper examines public conflict over the rapid growth of the Tasmanian salmon aquaculture industry and associated environmental and social impacts. By conducting a media analysis, triangulated with key stakeholder interviews, we find news media discourse was predominantly framed by environmental risk, expansion of the industry and the in/effectiveness of Government regulation. Environmental science and community interests were conflated within these themes, leading to a perceived lack of transparency and loss of trust in both environmental science information and regulation of environmental impacts. Government, salmon companies and science institutions were the most frequently mentioned stakeholder groups within news media, suggesting they had power to facilitate virtuous cycles – that is, shared goals and language. However, these stakeholder groups were portrayed to be outwardly opaque in their communications of, and lacking engagement in, decision-making processes. By revealing how science, societal values and decision-making were negotiated in news media through this conflict, we hope to contribute to the understanding of how vicious and virtuous cycles can be facilitated by various stakeholders and within media.

Place-Based Directionality of Innovation: Tasmanian Salmon Farming and Responsible Innovation

The aim of this paper has been to explore, in depth, the place-based conditions enabling and constraining the directionality of responsible innovation in the Tasmanian salmon farming industry, and to discuss how this case can inform the broader literature on directionality of innovations. Theoretically, we argue that the combination of literature on responsible research and innovation (RRI), regional innovation system (RIS) and discourse theory is a useful starting point for addressing innovation as a territorial complex consisting of a material dimension in terms of technologies and resources, an organizational dimension in terms of innovation systems and regulations, and a discursive dimension in terms of narratives in play. When applying the complex to analyze how place-based conditions have enabled and constrained the directionality of responsible innovation in the Tasmanian salmon industry, the case discerns that the directionality of responsible innovation arises from a rather mature and well-organized regional innovation system, which allows multiple stakeholders to articulate their narratives. Under such circumstances, responsible innovation becomes a multidimensional, interactive, and co-created phenomenon consisting of several dilemmas. Still, although the contextualization of responsible innovation is highlighted, our case study acknowledges that certain “universal” characteristics shine through. By this we mean that context sensitivity must not supersede the fact that place-based responsible innovation is always subject to some generic dynamism: under all circumstances there will be a territorial innovation complex at play.

Seawater transmission and infection dynamics of pilchard orthomyxovirus (POMV) in Atlantic salmon (Salmo salar).

The Tasmanian salmon industry had remained relatively free of major viral diseases until the emergence of pilchard orthomyxovirus (POMV). Originally isolated from wild pilchards, POMV is of concern to the industry as it can cause high mortality in farmed salmon (Salmo salar). Field observations suggest the virus can spread from pen to pen and between farms, but evidence of passive transmission in sea water was unclear. Our aim was to establish whether direct contact between infected and naïve fish was required for transmission, and to examine viral infection dynamics. Atlantic salmon post-smolts were challenged with POMV by either direct exposure via cohabitation or indirect exposure via virus-contaminated sea water. POMV was transmissible in sea water and direct contact between fish was not required for infection. Head kidney and heart presented the highest viral loads in early stages of infection. POMV survivors presented low viral loads in most tissues, but these remained relatively high in gills. A consistent feature was the infiltration of viral-infected melanomacrophages in different tissues, suggesting an important role of these in the immune response to POMV. Understanding POMV transmission and host-pathogen interactions is key for the development of improved surveillance tools, transmission models and ultimately for disease prevention.

Media representations of seafood certification in Australia: Mobilising sustainability standards to attack or defend the value of an industry

Certification schemes respond to increasing environmental and social concerns about sustainability by encouraging consumer demand for ‘sustainable’ products. Such schemes have been a focus of much media coverage and the seafood sector is no exception with many seafood sustainability issues, including those related to both fisheries and aquaculture management, being widely reported on. This paper analyses how the certification schemes of the two best-known seafood sustainability standards organizations, the Marine Stewardship Council (MSC) and the Aquaculture Stewardship Council (ASC) certification, were presented in news media coverage during a period of conflict surrounding the sustainable production and management of seafood in Australia. Employing a content analysis of Australian online and print news media published between 2015 and 2018, we find that the MSC label was used to highlight the sustainability of fisheries all around Australia, while the ASC label was mainly used in the context of the Tasmanian salmon aquaculture industry, with both labels presented as ‘gold standards’. While we also find that ASC certification was used by ENGOs to attack the Tasmanian salmon industry and to question the validity of the ASC label, our data highlight that ASC and MSC certification was primarily used by industry as a tool to demonstrate its sustainability credentials, with the specifics of the certification schemes themselves receiving very little media attention.

International Trade of Chilean and Tasmanian Salmon and the Governmental Human Resource Policy enabling its Expansion

International trade policy theorists have repeatedly focused their works on actors developing or implementing policies, rather than the actual policies themselves. Dani Rodrik, Chalmers Johnson and Peter Evans are amongst those renowned international trade and industrialization scholars who dedicated most of their research to human resource development in countries that delivered miraculous economic growth. Chile may be considered one of those miraculous states, in part due to the development of its salmon fishing industry. Tasmania, another southern hemisphere salmon producing region, has also procure a State-guided sectorial development. Both face common attributes and challenges. On one hand, Chile and Tasmania salmon development is highly explained due to the existence of a bureaucratic regime highly supportive of human capital development in the new sector. On the other hand, still both face challenges to find the right balance between profitability and environmental sustenance. Chile has shown record export growth, but it has raised questions on sanitary management; while Tasmania has enforced strict environmental compliance, it has hardly earned anything from exports of Salmon.

Parasitic isopods Ceratothoa banksii (Leach, 1818) and Nerocila orbignyi (Guérin-Méneville, 1832) of farmed Atlantic salmon and their potential as vectors of Neoparamoeba perurans (Young et al. 2007) in Tasmania

Reiterative freshwater bathing is the main treatment to control amoebic gill disease (AGD) of farmed Atlantic salmon in Tasmania, Australia. Regular freshwater exposure appears to control ectoparasitic cymothoid isopods, which were only seen at high prevalence and intensity in summer when fish had not been treated for over 100 days. With the potential advent of non-freshwater AGD treatments or increased periods between freshwater bathing due to selective breeding for AGD resistance, it is possible that cymothoid parasitism will become an increasing threat on Tasmanian salmon farms. In order to establish whether isopods could be vectors of Neoparamoeba perurans Young et al. 2007 (the causative agent of AGD), gill isopods were collected from salmon that had not been bathed for seven months and carried a 95% prevalence of isopods, including Ceratothoa banksii (Leach, 1818) and Nerocila orbignyi (Guérin-Méneville, 1832). PCR analyses of gill swabs indicated that 82% of salmon were positive for N. perurans while 41% of the sampled isopods were positive for N. perurans on external surfaces. When internal material was analysed, only 9% of the isopods were positive for the amoeba, but in very low concentration. Quantitative analysis showed no correlation between the concentrations of N. perurans from gill swabs and the isopods from the same individual fish. Thus, it is unlikely that these isopods act as a significant reservoir or vector for N. perurans.

Publicised scrutiny and mediatised environmental conflict: The case of Tasmanian salmon aquaculture

This paper analyses mediatised environmental conflict over the Tasmanian salmon aquaculture industry's performance. It compares the Senate Inquiry into the “Regulation of the fin-fish aquaculture industry in Tasmania”, the influential Four Corners investigative journalism television program ‘Big Fish’ and news media coverage following each of these mediatised public investigations. The concept of “mediatised environmental conflict” is applied to reveal how these different modes of investigation influence public debate. Both the Senate Inquiry and the Four Corners program allowed previously invisible actors and networks to be made visible, while rendering others largely silent, particularly scientists despite strong references to science within the debate. Also, the traditional role of ENGOs in holding industries and Governments to account has shifted in this case to an industry player. Considerable differences in the discourses was observed, raising further questions concerning accountability and transparency in public-policy decision-making in relation to management of marine resources.

Implications of high animal by-product feed inputs in life cycle assessments of farmed Atlantic salmon

Animal by-products may be increasingly relied upon to satisfy nutritional requirements of salmonids and other fed aquaculture species as demand for fish meal outpaces supply. Previous studies of aquaculture supply chains have included either no animal by-product inputs or small inputs of poultry by-products. Australian Atlantic salmon production includes high use of feed inputs derived from poultry and mammalian by-products and provides a case study to explore the environmental implications and methodological challenges associated with these inputs. Life cycle assessment was carried out on a vertically integrated salmon production system in Tasmania, representing approximately 40% of Australian Atlantic salmon production. The system included feed production, smolt/juvenile production, farm grow-out, processing and packaging, and distribution of head-on gutted salmon to market. Impacts from animal production were allocated to by-products on a gross chemical energy basis. Scenario analyses were conducted to determine the extent to which changes in feed conversion ratio, feed composition, and other variables affect results. Sensitivity analysis was carried out on the allocation method for fishery and animal by-products. Environmental impacts associated with Tasmanian salmon fed high quantities of animal by-products were markedly higher than those of previously assessed systems. All impacts were driven by feed production with the exception of eutrophication potential, which was driven equally by feed production and nutrient loss during grow-out. Animal by-products accounted for the majority of all impacts from feed production. Adopting a feed composition without animal by-products would result in dramatic improvements, including a 70% decrease in greenhouse gas emissions. Allocation choice had a clear effect on results, with biophysical allocation methods placing much more burden from animal production on fed systems than economic or no-impact allocation methods. The use of animal by-product inputs in aquaculture feeds has a substantial effect on the environmental profile of farmed salmon products. The magnitude of this effect is dependent on the allocation method chosen for the treatment of products and by-products in upstream systems. The high impact of such systems recognizes the environmental cost of future aquaculture production that may rely more on intensive and high-impact animal production inputs as more efficient fishery inputs become increasingly limited relative to demand.

Technology selection—the impact of economic risk on decision making

ABSTRACTDeveloping an understanding of economic variance (risk) is critical when evaluating alternative aquaculture production technologies. This article assesses the efficacy of employing a quantitative stochastic analysis technique to support technology selection decision making by undertaking a case study investment assessment of three alternative production expansion strategies (offshore sea-pens, land-based RAS growout and larger post-smolt) for the Tasmanian salmon industry. Results demonstrate that salmon aquaculture is undertaken with considerable underlying levels of economic risk, expansion offshore probably represents the lowest initial capital investment and greatest economic return, and that levels of financial uncertainty increase with land-based RAS production. The study highlights stochastic modeling provides significant “added-value” over single-point deterministic analysis and that developing an appreciation of the input variability is a key component in critically evaluating alternative production technologies.

Diversity and linkage disequilibrium in farmed Tasmanian Atlantic salmon.

Farmed Atlantic salmon (Salmo salar) is a globally important production species, including in Australia where breeding and selection has been in progress since the 1960s. The recent development of SNP genotyping platforms means genome-wide association and genomic prediction can now be implemented to speed genetic gain. As a precursor, this study collected genotypes at 218132 SNPs in 777 fish from a Tasmanian breeding population to assess levels of genetic diversity, the strength of linkage disequilibrium (LD) and imputation accuracy. Genetic diversity in Tasmanian Atlantic salmon was lower than observed within European populations when compared using four diversity metrics. The distribution of allele frequencies also showed a clear difference, with the Tasmanian animals carrying an excess of low minor allele frequency variants. The strength of observed LD was high at short distances (<25kb) and remained above background for marker pairs separated by large chromosomal distances (hundreds of kb), in sharp contrast to the European Atlantic salmon tested. Genotypes were used to evaluate the accuracy of imputation from low density (0.5 to 5K) up to increased density SNP sets (78K). This revealed high imputation accuracies (0.89-0.97), suggesting that the use of low density SNP sets will be a successful approach for genomic prediction in this population. The long-range LD, comparatively low genetic diversity and high imputation accuracy in Tasmanian salmon is consistent with known aspects of their population history, which involved a small founding population and an absence of subsequent introgression. The findings of this study represent an important first step towards the design of methods to apply genomics in this economically important population.

The Atlantic Salmon Salmo salar in Australia

The multimillion dollar Tasmanian Atlantic Salmon aquaculture industry grew from a shaky beginning with just 36 ripe females in the 1970's. The early unsuccessful attempts to introduce Atlantic Salmon (Salmo salar) to Australia which started in 1841 are summarised. By 1960 no known populations of Atlantic Salmon existed in Australia so Dr D.D. Francois arranged the import of Atlantic Salmon ova in 1963, 1964 and 1965. By 1972 when I took over management of Atlantic Salmon in N. S.W., the remaining stocks had become very low, only 36 ripe females remaining, and the importation of new stocks were prohibited. By 1979 1,000,000 ova were laid down for that year although mortalities were high. In the 1980's several shipments of these Atlantic Salmon ova were supplied to Tasmania, and from these, the multimillion dollar Tasmanian Salmon aquaculture industry has developed. Lake Jindabyne is still stocked annually with Atlantic Salmon and reasonable angler returns result, but no breeding in the wild has been reported.

Laboratory evaluation of sample collection methods (organs vs swabs) for Tasmanian salmon reovirus detection in farmed Atlantic salmon, Salmo salar L.

The use of swabs relative to organs as a sample collection method for the detection of Tasmanian salmon reovirus (TSRV) in farmed Tasmanian Atlantic salmon, Salmo salar L., was evaluated by RT-qPCR. Evaluation of individual and pooled sample collection (organs vs swabs) was carried out to determine the sensitivity of the collection methods and the effect of pooling of samples for the detection of TSRV. Detection of TSRV in individual samples was as sensitive when organs were sampled compared to swabs, and in pooled samples, organs demonstrated a sensitivity of one 10-fold dilution higher than sampling of pooled swabs. Storage of swabs at 4°C for t=24h demonstrated results similar to those at t=0. Advantages of using swabs as a preferred sample collection method for the detection of TSRV compared to organ samples are evident from these experimental trials.

Genetic variation in parasite resistance of Atlantic salmon to amoebic gill disease over multiple infections

Genetic selection is being developed as a management tool for the control of amoebic gill disease (AGD) in Atlantic salmon. AGD is caused by an external gill parasite and is an animal health issue that results in significant economic loss to the Tasmanian salmon industry. This paper presents genetic parameters for AGD resistance, describes patterns of genetic variation over multiple infection cycles, and discusses the development of a selective breeding program to exploit this variation.Measurements of visible gill signs were made on over 12,000 individuals representing 326 sires and 297 dams from four genetically linked year classes. Between three and six sequential infections were measured on each year class. All measures of gill signs in all year classes had significant genetic variation with heritabilities ranging from 0.09±0.03 to 0.56±0.07. Genetic correlations between infections indicate two distinct traits which are only weakly correlated (average rg=0.24). One is measured at first infection on naïve fish and the other can be measured at all subsequent infections. This pattern is suggestive of an adaptive immune response for reinfections, and conforms with patterns seen for resistance to other parasitic diseases in terrestrial livestock. In an analysis combining all year classes, the heritability for first infection was 0.14±0.02 and heritabilities for reinfections ranged from 0.23±0.08 to 0.40±0.03. Reinfections appeared to be mostly under common genetic control, although there appear to be additional genetic traits that cause lower correlations for a small proportion (about 10%) of the population. Consistent and stable patterns of inheritance are indicated by the medium to high genetic correlations between year classes and by the high genetic correlations between infection cycles with a seasonal shift. Estimation of genetic correlations between AGD resistance and growth rate are problematic due to confounding effects but it is likely that this correlation is near zero.Selection for AGD resistance can assist with disease management and is part of the breeding objective of the Tasmanian salmon breeding program. Adaptive AGD resistance is one of the primary selection traits and a field challenge based on assessment of gill signs is an effective way of selecting for resistance. The current selective breeding strategy is predicted to increase the interval between treatments by 3% per year.

Effect of elevated temperature on estrogenic induction of vitellogenesis and zonagenesis in juvenile Atlantic salmon (Salmo salar)

Fertility and embryo survival rates are often low in eggs from thermally challenged Tasmanian Atlantic salmon, partly due to a reduction in plasma 17β-estradiol (E2) levels. We used juvenile Atlantic salmon to assess whether hepatic tissue remains responsive to stimulation by E2 at the higher temperatures sometimes encountered by Tasmanian salmon during summer. E2 administration stimulated vitellogenin (Vtg) and estrogen receptor alpha transcription at 14°C and 22°C, although induction of Vtg occurred more rapidly at 22°C. Consequently, plasma Vtg levels increased and reached a plateau more quickly at 22°C. Zona pellucida (Zp) B and C transcription was significantly lower in E2-treated fish at 22°C relative to 14°C. This shows that the Vtg gene is E2-responsive at high temperature unlike Zp B and C genes that displayed traits of thermal inhibition. Therefore, estrogen replacement therapy in adult salmon may offset some, but not all thermal inhibition of reproductive function.

Movements of fur seals following relocation from fish farms

Abstract The movement patterns of Australian and New Zealand fur seals trapped on salmon farms in south‐east Tasmania and relocated hundreds of kilometres away, were monitored using satellite telemetry. Australian fur seals released 470 km away by sea returned to farms after an average of 8.5±4.4 days (n=9 trips) and those released at 140 km returned after 3.2±0.8 days (n=4 trips). New Zealand fur seals (n=5 trips) averaged a return time of 6.8±1.2 days from 300 km. When in south‐east Tasmania, both seal species undertook short trips to sea (mean 2.6 days) from haul‐out sites (minimum distance from farms 21 km) with 33% (1.8 days) of this time spent within 5 km of farms. Mean haul‐out duration was 1.1 days. In summer, Australian fur seals repeatedly travelled between northern Bass Strait islands and southern Tasmanian waters following the Tasmanian east coast. Seals did not visit farms during this time. Southern Tasmanian waters are important foraging grounds for fur seals and potential exists for a substantial number of seals to visit nearby fish farms. Farms provide predictable food resources from penned and escaped salmon, and wild fish attracted to the area. Australian fur seals trapped at Tasmanian salmon farms regularly visited breeding colonies on islands in Victoria. Copyright © 2008 John Wiley &amp; Sons, Ltd.

Mitigating fur seal interactions: relocation from Tasmanian aquaculture farms

Abstract At Tasmanian salmon aquaculture farms, fur seals were trapped and relocated to reduce interactions with stock, operations and equipment. From 1990 to 2005, 4517 relocations of 1124 seals were undertaken, peaking at 1203 relocations in 2003. Of the relocations, 56% were recaptured seals. Most seals had less than 10 captures (46%), with 3% trapped more than 20 times. Relocations were mostly seasonal, occurring in the austral winter and spring with a peak in August. Seal recapture intervals were highly variable, ranging from days to years. Within the same year, recapture intervals per seal ranged from 4 to 258 days, mean 36 days. Australian fur seals were trapped more frequently than New Zealand fur seals. The first trapped New Zealand fur seal was identified in 2000. Relocation provides short‐term relief from seal interactions but does not mitigate the interaction problem in the longer term. The core of the seal interaction problem is the current inability to exclude seals from pens and fish stock. Salmon farms are providing a predictable, accessible food source for seals. Copyright © 2008 John Wiley &amp; Sons, Ltd.