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Australia's fisheries have experience in responding individually to specific shocks to stock levels (for example, marine heatwaves, floods) and markets (for example, global financial crisis, food safety access barriers). The COVID-19 pandemic was, however, novel in triggering a series of systemic shocks and disruptions to the activities and operating conditions for all Australia's commercial fisheries sectors including those of the research agencies that provide the information needed for their sustainable management. While these disruptions have a single root cause—the public health impacts and containment responses to the COVID-19 pandemic—their transmission and effects have been varied. We examine both the impacts on Australian fisheries triggered by measures introduced by governments both internationally and domestically in response to the COVID-19 pandemic outbreak, and the countermeasures introduced to support continuity in fisheries and aquaculture production and supply chains. Impacts on fisheries production are identified by comparing annual and monthly catch data for Australia's commercial fisheries in 2020 with averages for the last 4–5 years. We combine this with a survey of the short-term disruption to and impacts on research organisations engaged in fisheries monitoring and assessment and the adaptive measures they deployed. The dominant impact identified was triggered by containment measures both within Australia and in export receiving countries which led to loss of export markets and domestic dine-in markets for live or fresh seafood. The most heavily impact fisheries included lobster and abalone (exported live) and specific finfishes (exported fresh or sold live domestically), which experienced short-term reductions in both production and price. At the same time, improved prices and demand for seafood sold into domestic retail channels were observed. The impacts observed were both a function of the disruptions due to the COVID-19 pandemic and the countermeasures and support programs introduced by various national and state-level governments across Australia to at least partly mitigate negative impacts on harvesting activities and supply chains. These included protecting fisheries activities from specific restrictive COVID-19 containment measures, pro-actively re-establishing freight links, supporting quota roll-overs, and introducing wage and businesses support packages. Fisheries research organisations were impacted to various degrees, largely determined by the extent to which their field monitoring activities were protected from specific restrictive COVID-19 containment measures by their state-level governments. Responses of these organisations included reducing fisheries dependent and independent data collection as required while developing strategies to continue to provide assessment services, including opportunistic innovations to harvest data from new data sources. Observed short run impacts of the COVID-19 pandemic outbreak has emphasised both the vulnerability of fisheries dependent on export markets, live or fresh markets, and long supply chains and the resilience of fisheries research programs. We suggest that further and more comprehensive analysis over a longer time period of the long-run impacts of subsequent waves of variants, extended pandemic containment measures, autonomous and planned adaptive responses would be beneficial for the development of more effective counter measures for when the next major external shock affects Australian fisheries. [ABSTRACT FROM AUTHOR]

The longspined sea urchin, Centrostephanus rodgersii, is a climate-driven pest species in south-eastern Australia. The harvest of this species is highly encouraged and in Tasmania, the existing fishery is expanding resulting in a large amount of waste that needs disposal. Research into use of waste products as inputs for organic or biodynamic farming systems can help reduce costs of disposal and keep the industry profitable; by sustaining or incrementing sea urchin harvest the industry can assist in their control. In the current study, urchin waste was dried and finely ground to a powder and applied to tomato plants in a greenhouse to examine the effect on growth and productivity. Urchin waste powder (UWP) had a mineral composition of Ca (40 g 100 g−1), Mg (1.7 g 100 g−1), P (0.03 g 100 g−1), Fe (19.34 mg kg−1) and B (38 mg kg−1), a pH 8.06 in water and an Electrical Conductivity (EC) value of 7.64 dSm−1. Seven different treatment rates of UWP (0.3%; 0.5%; 0.8%; 1%; 2%; 3%; 5%), were added to 10 replicate pots containing 4 kg nutrient-poor potting mix planted with tomato (Variety K1) seedlings. Plant growth, yield, quality attributes and mineral content of tomato were measured under UWP treatments with comparison against a Hoagland solution control. UWP influenced tomato growth and productivity proportional to the quantity applied, however, the Hoagland solution control had a significantly greater yield. Potting mix pH increased from 6.8 to 7 and higher available P was detected in potting mix receiving higher rates of UWP. No phytotoxic effects were detected. The highest UWP treatment matched the Hoagland control in fruit quality and nutritional composition. Processing waste from the sea urchin fishery has potential as organic fertiliser or amendment providing plant-available Ca and some microelements such as Boron. [ABSTRACT FROM AUTHOR]

Environmental conditions experienced during the larval dispersal of marine organisms can determine the size‐at‐settlement of recruits. It is, therefore, not uncommon that larvae undergoing different dispersal histories would exhibit phenotypic variability at recruitment. Here, we investigated morphological differences in recently settled southern rock lobster (Jasus edwardsii) recruits, known as pueruli, along a latitudinal and temporal gradient on the east coast of Tasmania, Australia. We further explored whether natural selection could be driving morphological variation. We used double digest restriction site‐associated DNA sequencing (ddRADseq) to assess differences in the genetic structure of recently settled recruits on the east coast of Tasmania over 3 months of peak settlement during 2012 (August–October). Phenotypic differences in pueruli between sites and months of settlement were observed, with significantly smaller individuals found at the northernmost site. Also, there was a lack of overall genetic divergence; however, significant differences in pairwise FST values between settlement months were observed at the southernmost study site, located at an area of confluence of ocean currents. Specifically, individuals settling into the southernmost earlier in the season were genetically different from those settling later. The lack of overall genetic divergence in the presence of phenotypic variation indicates that larval environmental history during the dispersal of J. edwardsii could be a possible driver of the resulting phenotype of settlers. [ABSTRACT FROM AUTHOR]

Climate change increases the need to control range-extending species, which adversely impact their recipient ecosystem. Increasing populations of resident predators may be effective to counter such range-extension, but only if they consume the novel invaders at sufficient rates. In South-East Australia, poleward range-extending Longspined Sea Urchins (Centrostephanus rodgersii) are causing catastrophic ecological habitat transition to extensive urchin barrens. Tasmanian native Southern Rock Lobster (Jasus edwardsii) is a potential predator that could control further urchin expansion. Experimental feeding trials showed that range-extending Longspined Sea Urchins are the least preferred prey choice for Southern Rock Lobsters (3.8% predation events), when compared to three local species: abalone, urchins, and snails (36.6, 32.6, and 27%). Interestingly, habitat origin and naivete of lobsters to urchins affected urchin consumption with 85% being consumed by lobsters originating from urchin barrens. Low predation rates on Longspined Sea Urchin suggest that resident lobsters are unlikely to control further barren expansion unless a behavioural shift occurs. Results imply that potential control of Longspined Sea Urchins by Southern Rock Lobsters has previously been overestimated. Additional control methods are needed to safeguard ecological communities and important commercial stocks from this climate change-induced, range-extending pest species. [ABSTRACT FROM AUTHOR]

A large gap has been identified between the current and optimal economic performance of wild-capture commercial fisheries in Australia. Economic approaches have the potential to assist fisheries to bridge this gap, such as bio-economic models that combine biology with fishing costs to evaluate the economic performance of a broad range of management measures. Economic objectives are prevalent in overarching Australian fisheries legislation, however economic data is often not collected and economic analyses or instruments not broadly applied. This paper reviews selected Australian fisheries to demonstrate the accrued economic benefits from applying formal bio-economic models and conducting empirical analyses of the impact of supply on product value. Challenges to the implementation and continued use of economic analyses and instruments are discussed including: (i) short-term transition costs and associated trade-offs between ecological, economic, social and political objectives; (ii) scarce logistical and financial capacity to collect and analyse economic data; (iii) a lack of desire among industry to change and transition to economic targets such as maximum economic yield (MEY), particularly when it is associated with lower catches; and (iv) a lack of economic literacy among fisheries managers and industry. It is contended that many of these challenges initially arise from an absence of clearly identified and prioritised objectives within overarching legislation and management plans. Once objectives are prioritised, limited resources can be allocated more efficiently to improve data collection, economic analysis and increase awareness as well as education of managers and industry. [ABSTRACT FROM AUTHOR]

Substantial economic opportunities have been identified in many Australian fisheries but may remain unimplemented due to the perception that the role of government is to ensure harvests are biologically sustainable, while economic decisions should be left to the commercial industry. This paper explores the role of government in driving changes that increase revenue and profit from fisheries (termed economic benefit). Australian fisheries resources are managed by eight different jurisdictions. While each have separate legislation, there is invariably a responsibility to manage on behalf of, and to the benefit of the public, who are the owners of the resource. This paper uses case studies to explore how government can struggle to determine the public interest, separate this from private interests and then implement management changes to ensure the public utility is maximised. Common problems were: (i) overarching economic objectives, which define who should benefit, were often ambiguous and open to interpretation; (ii) the public interest was usually abstract and often under-represented in decision-making processes, (in contrast to industry, who have direct representation); (iii) special interest groups were often able to lobby against changes; and (iv) government was often reluctant to seize opportunities to increase economic benefit when there was significant industry opposition to management changes. In drawing attention to these challenges and how they have been overcome historically, it is argued that government has both a role and requirement under their legislative objectives to take the lead in implementing measures that increase the economic benefit from Australian fisheries. [ABSTRACT FROM AUTHOR]

The distance between where food is produced and consumed is increasing, and is often taken as evidence of an unsustainable global food system. Seafood is a highly traded commodity yet seafood sustainability assessments do not typically consider the impacts of the movement of products beyond the fishery or farm. Here we use life cycle assessment to examine the carbon footprint of the production and distribution of select seafood products that are consumed in Australia and determine differences in the sustainability of imports and their domestically produced counterparts. We found that the distance food is transported is not the main determinant of food sustainability. Despite the increased distance between production and consumption, carbon footprints of meals from imported seafood are similar to meals consisting of domestically produced seafood, and sometimes lower, depending on the seafood consumed. In combining LCA with existing seafood sustainability criteria the trade-offs between sustainability targets become more apparent. Carbon ‘footprinting’ is one metric that can be incorporated in assessments of sustainability, thereby demonstrating a broader perspective of the environmental cost of food production and consumption. [ABSTRACT FROM AUTHOR]

Fisheries management decisions have the potential to influence the safety of fishers by affecting how and when they fish. This implies a responsibility of government agencies to consider how fishers may behave under different policies and regulations in order to reduce the incidence of undesirable operational health and safety outcomes. In the Tasmanian southern rock lobster fishery, Australia, the expansion of the quota lease market under individual transferable quota (ITQ) management coincided with a rise in the number of commercial fishing fatalities, with five between 2008 and 2012. A discrete choice model of daily participation was fitted to compare whether physical risk tolerance varied between fishers who owned the majority of their quota units (quota owners) and those who mainly leased (lease quota fishers). In general, fishers were averse to physical risk (wave height), however this was offset by increases in expected revenue. Lease quota fishers were more responsive to changes in expected revenue than quota owners, which contributed to risk tolerance levels that were significantly higher than those of quota owners in some areas. This pattern in behaviour appeared to be related to the cost of leasing quota. Although ITQs have often been considered to reduce the incentive for fishers to operate in hazardous weather conditions, this assumes fishing by quota owners. This analysis indicated that this doesn't hold true for lease quota fishers in an ITQ system, where in some instances there remains an economic incentive to fish in conditions with high levels of physical risk. [ABSTRACT FROM PUBLISHER]

Monthly monitoring of puerulus settlement across South Australia, Victoria and Tasmania has been undertaken since the early 1990s. Firstly, annual trends in settlement were spatially analysed across the three States. In South Australian and Victorian settlement patterns were closely related. In Tasmania, settlement sites along the northeast coast were positively correlated, but showed no relationship with areas further south or in any other State. Secondly, annual settlement indices were correlated with lagged estimates of fishery recruitment. In South Australia, the strongest correlations between settlement and recruitment to legal size were observed using a 4–5- year time-lag. Within Victoria and Tasmania, the period from settlement to recruitment at 60 mm carapace length (CL) was 2 and 3 years, respectively. The period from 60 mm to legal size was another 2–3 years, suggesting that the total time from settlement to the fishery ranges from 4–6 years in these regions. The correlation between settlement and recruitment was used to forecast future estimates of exploitable biomass in one region of South Australia. The results indicate that puerulus monitoring is a relatively robust indicator of future fishery performance and should be regarded as an important data source for rock lobster resources within south-eastern Australia. [ABSTRACT FROM PUBLISHER]

Climate change will impact on ecological, social, and economic elements of fisheries; however, the three are seldom considered in an integrated fashion. We develop a fishery-level assessment of economic resilience to climate change for the Tasmanian rock lobster fishery, a linked social–ecological system. We outline the main climate change forcing influences that link climate change to the fishery via changes in lobster abundance, distribution, and phenology. Using a bottom-up approach, we identify twelve economic attributes strongly related to the fisheries’ economic resilience to climate change. Resilience attributes are grouped according to the level of the economic domain (business, sectoral, and governance). Attributes are then evaluated to determine the overall economic resilience of the rock lobster fishery in the context of the specific nature of predicted climate change effects. We identify areas of low resilience in the economic sub-system for this fishery. Evaluating the economic resilience of regional fisheries using this integrated, interdisciplinary framework provides a practical, parsimonious, and conceptually sound basis for undertaking comprehensive and contextually tailored assessments of climate change impacts and economic vulnerability. The framework can be extended to include a broader range of climate change impacts and the social domain of the human sub-system. [ABSTRACT FROM AUTHOR]

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The article explores on the spatial and depth variation in shell color for the Tasmanian, South Australian and Victorian fisheries. It notes on using catch sampling data where proportion of red lobsters decreased with depth and is prevalent at depths less than 30 meter (m), whereas paler lobsters are greater in number in the deeper depth ranges. Meanwhile, it cites that catches of pale lobsters from greater depths remain low in these areas. Furthermore, it analyzes on the impact of these shell color variation in lobsters to the commercial industry of Tasmania and Australia.

We describe a first estimate of the potential to increase production from Australia's commercial fisheries based on the difference between current catches and maximum sustainable yield (MSY). MSY is not being advocated as a target reference point but enables a level of consistency across species and/or jurisdictions with different reference points. MSY estimates were obtained for 290 species/stocks that comprised 84% of annual landings. 75% of the estimates were computed using methods applied specifically for this study, aided by an assessment framework, and supporting software. The catch-MSY method was used extensively given the lack of formal assessments for many species, and the limitations of taking this approach are discussed. The results indicated that potential production could be more than double the current national catch (an increase over current catches of about 124%), but potential increases varied considerably among Federal, State and Territory jurisdictions. The potential for increased production was particularly influenced by predictions for highly productive small pelagic fishes, although ignoring the potential for increased catches of these species still led to an estimate of an increase of almost 80% over current catches. Other factors such as whether an increase in production has market demand are also clearly important, along with other social and economic issues. Impacts on ecosystem sustainability and the consequences of climate change were beyond the scope of this study and would need to be considered in separate analyses. However, in making our estimates of potential production we acknowledged the issues with attempting to use single species approaches to provide fish community wide estimates and acted conservatively with our interpretation. Consequently, the results presented in this paper provide useful insights into possible biologically sustainable catches and the potential for increased production. • The potential for an increase in total commercial fisheries production across multiple jurisdictions and fisheries in Australia. • Maximum sustainable yield was estimated for 290 species/stocks comprising 84% of total landings. • Potential production could be doubled and, accounting for small pelagic species, an increase in production of almost 80% is possible. • Increases depend on the target reference points used in the management and the depletion level of each species/stock. • Further research would be required to evaluate market demand and environmental implications. [ABSTRACT FROM AUTHOR]

Communicating the performance of commercial fish stocks is a fundamental role of fisheries management. This is often undertaken by reporting stock status relative to limit reference points (LRP). Reporting against LRP is effective in drawing attention to stocks that are overfished but does not identify fisheries where performance could be improved by shifting stocks closer to target reference points (TRP), that is, benefit can be foregone despite stocks being fished sustainably. This study examined the performance of Australian fish stocks against a TRP of 40–60% of unfished biomass, the level at which economic performance is generally optimised. Stocks examined were drawn from the 2016 Status of Australian Fish Stocks report, which is designed to report on stock status relative to LRP at a national level. Only stocks with an estimate of biomass or status relative to explicitly defined reference points were considered. Of 123 stocks evaluated, 41 (33%) were at target biomass levels, 28% were above and 39% below. This result, in combination with the major output of the 2016 SAFS report, shows that although most Australian stocks are not overfished, many are outside levels that would deliver greatest benefits. While maintaining all stocks at target levels may be impractical given the dynamic nature of fisheries, failing to maximise the number of stocks at target levels reflects lost ecological, economic and social potential. Assessing stocks relative to TRP in addition to LRP would highlight opportunities for improving fisheries while still addressing the fundamental requirement of preventing stock depletion. [ABSTRACT FROM AUTHOR]

Bait is an often-overlooked component in studies addressing operational and ecological risks in commercial fishing. One of the most valued fisheries in Australia, the Southern Rock Lobster Fishery, lacked analysis of bait use, which is relevant to both assessing ecological interactions of the fishery and also concerns around future supply. We conducted a survey to determine what species are predominantly being used as bait, assessed these species' sustainability status, and explored any risks around future supply. We found that fishers preferred a limited number of bait species and that some were being sourced from fisheries with an 'unknown' sustainability status, and many fishers were concerned about future bait supply. Insecurity of existing supply means that other bait options need to be explored. Furthermore, ongoing monitoring of species being used for bait would assist any future third party sustainability accreditation. • Bait is often ignored when addressing operational & ecological risks in fisheries. • Fishers preferred a limited number of bait species. • Some bait is sourced from fisheries with an 'unknown' sustainability status. • Many fishers were concerned about future bait supply. • Insecurity of existing supply means that other bait options need to be explored. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented in response to the article "Australia's dietary guidelines and the environmental impact of food from paddock to plate," by L. A. Selvey and M. G. Carey in the 2013 issue.

Managing fisheries to meet social, economic and ecological objectives is a fundamental problem encountered in fisheries management worldwide. In Australia, fisheries management involves a complex set of national and sub-national policy arrangements, including those designed to deliver against ecologically sustainable development (ESD) objectives. The complex policy framework makes ensuring policy coherence and avoiding unintended consequences difficult, particularly where potential trade-offs are not made explicit. Coherence, or potential policy weakness, of Australian fisheries management in relation to ESD objectives was examined in a subset of Australian wild capture fisheries, at national and jurisdictional scales. Coherent policy frameworks with ESD objectives were found to be more likely at the legislative-level across jurisdictions (horizontal coherence), than other levels of implementation. Many fisheries had problems demonstrating coherence between legislation and management plans due to lack of inclusion of ESD policy themes at management and operational levels. Case studies revealed substantial variation in the likelihood for horizontal and vertical coherence between fisheries policy frameworks managing the same species. The lack of explicit ESD objectives observed in many Australian fisheries suggests a high likelihood of incoherence in fisheries management, or alternatively that managers may be informally persuing higher levels of policy coordination and coherence than can be detected. Lack of detectability of coherence is problematic for demonstrating accountability and transparency in decision-making and public policy. Furthermore, use of discretion by managers when developing management plans, in order to overcome policy weakness, may lead to drifts in individual management direction within a jurisdiction. • Managing fisheries to meet social, economic and ecological objectives is challenging. • Coherence is a required attribute of policy frameworks to reduce unintended impacts. • Many fisheries did not show coherence between legislation and management plans. • Lack of detectability of coherence is problematic for management accountability. [ABSTRACT FROM AUTHOR]

Australian marine wild-capture fisheries are managed by eight separate jurisdictions. Traditionally, fishery status reports have been produced separately by most of these jurisdictions, assessing the fish stocks they manage, and reporting on the effectiveness of their fisheries management. However, the format, the type of stock status assessments, the thresholds and terminology used to describe stock status and the classification frameworks have varied over time and among jurisdictions. These differences complicate efforts to understand stock status on a national scale. They also create potential misunderstanding among the wider community about how to interpret information on the status of fish stocks, and the fisheries management and science processes more generally. This is especially true when considering stocks that are shared across two or more jurisdictional boundaries. A standardised approach was developed in 2011 leading to production of the first national Status of key Australian fish stocks reports in 2012, followed by a second edition in 2014 ( www.fish.gov.au ). Production of these reports was the first step towards a broader national approach to reporting on the performance of Australian fisheries for target species and for wider ecosystem and socioeconomic consequences. This paper outlines the challenges associated with moving towards national performance reporting for target fish stocks and Australia’s successes so far. It also outlines the challenges ahead, in particular those relating to reporting more broadly on the status of entire fisheries. Comparisons are drawn between Australia and New Zealand and more broadly between Australia and other countries. [ABSTRACT FROM AUTHOR]

• Southern Rock Lobster Jasus edwardsii supports important fisheries across the States of South Australia, Victoria and Tasmania. • Previous studies across the region have identified considerable synchrony in both larval settlement and recruitment. • This study analysed long-term trends in Surplus Production (SP) as a measure of annual stock productivity. • The results highlighted a common trend across south-eastern Australia, where SP declined rapidly from the late 1990s and early to mid-2000s.. • These results may reflect a regime shift in Southern Rock Lobster productivity, which should be considered in the future management of the resource. In south-eastern Australia, Southern Rock Lobster Jasus edwardsii supports important regional fisheries across the States of South Australia, Victoria and Tasmania. Previous studies across the region have identified considerable synchrony in both larval settlement and recruitment, suggesting that the mechanisms driving these processes occur across broad spatial scales. This study aimed to further examine cross-jurisdictional fishery patterns by analysing long-term trends in Surplus Production (SP) as a measure of annual stock productivity. The results showed evidence of a common trend across south-eastern Australia. Specifically, a substantially rapid decline in SP was observed around the late 1990s and early to mid-2000s period. This decline was particularity evident in both the Northern Zone of South Australia and the Tasmanian fishery. It is suggested that these results may reflect a regime shift in Southern Rock Lobster productivity across south-eastern Australia, which should be considered in terms of future management of the resource. [ABSTRACT FROM AUTHOR]

Population structure of many marine organisms is spatially patchy and varies within and between years, a phenomenon defined as chaotic genetic patchiness. This results from the combination of planktonic larval dispersal and environmental stochasticity. Additionally, in species with bi-partite life, postsettlement selection can magnify these genetic differences. The high fecundity (up to 500,000 eggs annually) and protracted larval duration (12-24 months) and dispersal of the southern rock lobster, Jasus edwardsii, make it a good test species for chaotic genetic patchiness and selection during early benthic life. Here, we used double digest restriction site-associated DNA sequencing (ddRADseq) to investigate chaotic genetic patchiness and postsettlement selection in this species. We assessed differences in genetic structure and diversity of recently settled pueruli across four settlement years and between two sites in southeast Australia separated by approximately 1,000 km. Postsettlement selection was investigated by identifying loci under putative positive selection between recently settled pueruli and postpueruli and quantifying differences in the magnitude and strength of the selection at each year and site. Genetic differences within and among sites through time in neutral SNP markers indicated chaotic genetic patchiness. Recently settled puerulus at the southernmost site exhibited lower genetic diversity during years of low puerulus catches, further supporting this hypothesis. Finally, analyses of outlier SNPs detected fluctuations in the magnitude and strength of the markers putatively under positive selection over space and time. One locus under putative positive selection was consistent at both locations during the same years, suggesting the existence of weak postsettlement selection., (© 2017 John Wiley & Sons Ltd.)

Five annual capture-mark-recapture surveys on Jasus edwardsii were used to evaluate the effect of sample size and fishing effort on the precision of estimated survival probability. Datasets of different numbers of individual lobsters (ranging from 200 to 1,000 lobsters) were created by random subsampling from each annual survey. This process of random subsampling was also used to create 12 datasets of different levels of effort based on three levels of the number of traps (15, 30 and 50 traps per day) and four levels of the number of sampling-days (2, 4, 6 and 7 days). The most parsimonious Cormack-Jolly-Seber (CJS) model for estimating survival probability shifted from a constant model towards sex-dependent models with increasing sample size and effort. A sample of 500 lobsters or 50 traps used on four consecutive sampling-days was required for obtaining precise survival estimations for males and females, separately. Reduced sampling effort of 30 traps over four sampling days was sufficient if a survival estimate for both sexes combined was sufficient for management of the fishery.

The net movement of individuals from marine reserves (also known as no-take marine protected areas) to the remaining fishing grounds is known as spillover and is frequently used to promote reserves to fishers on the grounds that it will benefit fisheries. Here we consider how mismanaged a fishery must be before spillover from a reserve is able to provide a net benefit for a fishery. For our model fishery, density of the species being harvested becomes higher in the reserve than in the fished area but the reduction in the density and yield of the fished area was such that the net effect of the closure was negative, except when the fishery was mismanaged. The extent to which effort had to exceed traditional management targets before reserves led to a spillover benefit varied with rates of growth and movement of the model species. In general, for well-managed fisheries, the loss of yield from the use of reserves was less for species with greater movement and slower growth. The spillover benefit became more pronounced with increasing mis-management of the stocks remaining available to the fishery. This model-based result is consistent with the literature of field-based research where a spillover benefit from reserves has only been detected when the fishery is highly depleted, often where traditional fisheries management controls are absent. We conclude that reserves in jurisdictions with well-managed fisheries are unlikely to provide a net spillover benefit.

Rock lobster growth is routinely measured for research to optimise management measures such as size limits and quotas. The process of estimating growth is complicated in crustaceans as growth only occurs when the animal moults. As data are typically collected by tag-recapture methods, the timing of moulting events can bias results. For example, if annual moulting events take place within a very short time-at-large after tagging, or if time-at-large is long and no moulting occurs. Classifying data into cases where moulting has / has not occurred during time-at-large can be required and can generally be determined by change in size between release and recapture. However, in old or slow growth individuals the moult increment can be too small to provide surety that moulting has occurred. A method that has been used since the 1970's to determine moulting in rock lobsters involves clipping the distal portion of a pleopod so that any regeneration observed at recapture can be used as evidence of a moult. We examined the use of this method in both tank and long-duration field trials within a marine protected area, which provided access to large animals with smaller growth increments. Our results emphasised that determination of moulting by change in size was unreliable with larger lobsters and that pleopod clipping can assist in identifying moulting events. However, regeneration was an unreliable measure of moulting if clipping occurred less than three months before the moult.