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Ecosystem-based fisheries management (EBFM) is often termed triple bottom line because it takes into account ecological, economic and social criteria. Effective implementation of EBFM requires development of appropriate governance structures for decision-making processes and management, so governance effectiveness and efficiency can be regarded as the fourth element in a ‘quadruple bottom line.’ Few fisheries have explicitly considered all four criteria within their resource assessments and harvest strategies. Furthermore, as some of these objectives may be in competition (e.g. employment levels, profit), a simultaneous evaluation of these criteria is required to identify the optimal level of fishing to deliver the best overall community outcome. The western rock lobster, Panulirus cygnus , resource in Western Australia is used as an EBFM case study by evaluating: sustainability of target species and effects on ecosystem and protected species; economics of the fishery; effect on employment, coastal communities and quality of recreational fishing; and governance effectiveness including explicit sectoral catch allocations, and the efficiency of monitoring and compliance systems. In 2010 the fishery moved from effort-controlled maximum sustainable yield (MSY) to a quota-controlled, maximum economic yield (MEY) system. This study explicitly examined how different levels of harvesting across the MSY to MEY range affected each of ten EBFM criteria. We confirmed that these individual objectives were maximised at different total allowable commercial catches. However an example is provided for weighting of objectives from a possible management perspective that identified the upper end of the MEY range as likely to generate the optimum outcome for this fishery. [ABSTRACT FROM AUTHOR]

The Shark Bay trawl fishery is Western Australia's most valuable prawn fishery (worth AUD$25 million in 2014). The 18-vessel fleet targets western king prawns ( Penaeus latisulcatus ), brown tiger prawns ( P. esculentus ) and also retains saucer scallops ( Ylistrum balloti ) and blue swimmer crabs ( Portunus armatus ). Increased fuel prices, falling prawn prices and lower catches of other species, following extreme environmental events, have impacted fishery profits. A biomass dynamics model with an economic component indicated that total revenue levels start to decline when annual effort increases beyond ~ 200 fishing days per boat. Annual effort required to achieve MEY, when based solely on prawn fishing, is 115–150 days per boat after accounting for fixed and variable fishing costs and annual fishing efficiency increases of 1–2%. From 2007–2014, the adjusted effort was 188–192 days per boat. Fishing occurred between March and November during 7–8 fishing periods, separated by 5–8 day (low catchability) moon closure periods. An empirical daily profit assessment (2007–2015), accounting for recruitment variation, daily prawn size compositions, monthly market prices for different prawn species and sizes, and daily fishing costs, showed vessels made profits on ~ 115–160 days and losses on ~ 15–55 days per year, when fishing occurred near the full moon. The fishery benefitted in 2013–2015 by starting later in the year and better targeting within-season effort. This management strategy within the effort-control framework, which improved profitability, maintained higher spawning stocks and reduced ecosystem fishing impacts, has wider application in prawn fishery management. [ABSTRACT FROM AUTHOR]

The western rock lobster ( Panulirus cygnus ) fishery is Australia’s most valuable single-species fishery, worth AUD$200–$400 million annually. Stock assessment for this fishery utilises the puerulus settlement to predict recruitment to the fishery 3–4 years later. This predictive ability has been particularly useful recently, due to an unprecedented period of low settlement between 2006/07 and 2012/13. Pre-emptive management action (~70% effort reduction) was taken to provide greater protection to the breeding stock which also moved the fishery to the maximum economic yield (MEY) level of effort for the projected recruitment. In 2010/11, the fishery moved from an effort-controlled to a quota-controlled fishery, which led to changes in fishing practices resulting in reductions in fishing costs and increases in lobster prices of about US$16/kg. This provided a unique opportunity to compare an MEY assessment under effort and quota controls. The MEY assessment under quota controls for a 5-year period indicated that annual harvest rates of 37–47% of legal biomass will achieve catches of 5780–7370 t. in 2014. This MEY target harvest range, which complements existing sustainability reference points based on egg production, is robust to a range of costs, prices and profit discount rates. This catch range enables industry/managers to take into account marketing implications and social issues (e.g. employment) in quota setting and therefore could be considered a socio-economic target. The MEY level of fishing has increased egg production to well above threshold levels that were based on maximum sustainable yield, providing the fishery with increased resilience when faced with environmental perturbations. This enables consideration for relaxing some existing biological controls, e.g. setose (mature) females, females above a maximum size, and lobsters 76–77 mm carapace length. The relaxation of these controls is estimated to increase profits by about AUD$15 million annually due to higher catch rates and reduced fishing effort while maintaining egg production well above threshold levels. [ABSTRACT FROM AUTHOR]

Abstract: The western rock lobster (Panulirus cygnus) fishery has been facing significant economic pressure from increasing costs, lower prices as well as predicted reduced catches due to low recruitment. A maximum economic yield (MEY) assessment estimated the fishing effort that would maximise the net present value of profits over 2008/09–2013/14 was about 50%–70% reduction of 2007/08 effort. The assessment accounted for fixed vessel costs and the variable pot lift cost. An important component of this assessment was the use of puerulus settlement time series that provided a reliable predictor of recruitment to the fishery 3–4 years later. This can be contrasted to most MEY assessments that would use an average catch-effort relationship rather than taking into account the expected recruitment. This predictive ability has been particularly useful as there has been a period of unusually low puerulus settlements over the 5 years (2006/07–2010/11) including the lowest two settlements in the 40-year time series. Due to the low settlements, substantial management changes were implemented in 2008/09 and 2009/10 (44% and 73% reduction in nominal fishing effort, respectively compared to 2007/08) to maintain the breeding stock at sustainable levels by having a significant carryover of legal lobsters into future years of lower recruitment. These effort reductions provided a unique opportunity to assess the economic impact of a fishery moving to an MEY effort level over two years. The CPUE increased from 1.1kg/pot lift in 2007/08 to 1.7 and 2.7 in 2008/09 and 2009/10, respectively. These CPUEs were much higher than the expected levels (1.2 and 1.1, respectively) if the 2007/08 effort had been maintained in these two years. The vessel numbers declined by 14% and 36% in 2008/09 and 2009/10, respectively, compared to 2007/08. The fishery profit increased by AUS$13 and 49 million for 2008/09 and 2009/10, respectively, compared to that estimated if the 2007/08 effort level had continued. This assessment demonstrates the economic benefits of fishing at a level close to that estimated for MEY under an input management regime. The management decision-rule framework is currently based on having the egg production above a threshold reference level to ensure sustainability and now a target reference point based on MEY principles is also being considered. [Copyright &y& Elsevier]

There are several ways to set biological reference points (BRP) for harvest strategies, but one of the most direct methods is to use the stock-recruitment relationship (SRR). Even if the SRR is not statistically significant, it provides valuable information about the spawning stock levels that don't influence the recruitment that is relevant to setting BRP. Environmental factors, particularly extreme events such as the 2011 Western Australia (WA) marine heatwave, are typically a major driver of recruitment, so it is important to assess their influence as ignoring this effect may bias the SRR. This study examines the SRR for 13 invertebrate stocks in WA including lobster, prawn, scallop, abalone, pearl oysters and crabs. These stocks have long time series of fishery-independent juvenile abundance indices, which provide a clear signal of the year-class strength that improves the ability to assess the SRR and environmental effects. Eleven stocks showed a significant environmental effect on recruitment with seven stocks demonstrating a significant spawning stock effect. The stock-recruitment data is used to determine the BRP based on the species' specific biological information, even when the relationship is not significant. Importantly, management action in the harvest control rules is not just reactive to low spawning stock levels but is proactive based on the juvenile abundance to ensure that the level of fishing results in future spawning stocks being maintained above the BRP. This evidence-based approach to setting BRPs and the proactive management approach adopted in the harvest strategy can be invaluable to fisheries management generally. [ABSTRACT FROM AUTHOR]

Fishing rights and co-management are considered important aspects of fisheries management. But with rights comes a responsibility to contribute data that improves stock assessments and harvest strategies. This responsibility should include contributing data based on fishery-independent surveys (FIS) that provide robust measures of stock abundance and greater confidence in stock assessments, reducing risks to stock sustainability and resulting in more reliable management. FIS conducted with stakeholders provides a direct link between stock abundance indices and their own experience giving them ownership and a better appreciation of stock status. We examine case studies from Western Australian fisheries in four categories: FIS conducted using research vessels; FIS conducted on recreational fisheries using citizen-science; FIS conducted using volunteer industry vessels, and FIS using chartered industry vessels. These FIS cover fisheries with different gear, management, fishing sectors, value and number of participants. The case studies demonstrate that there are a number of ways that FIS designs may be implemented, with each fishery having a unique approach with a common element that they represent standardised surveys. We consider that all fisheries require some type of FIS and this paper discusses options of how this might be achieved. However, FIS can be expensive, so surveys must be cost effective to ensure that they endure. The approach to developing FIS should include collaboration with stakeholders in a co-management agreement. The FIS could be a requirement of having fishing rights and taken into account when developing management arrangements, e.g. allocation of part of the entitlements for a FIS. • Fishers with fishing rights and co-management should support stock surveys. • Survey designs will vary depending on the objectives and fishery characteristics. • Case studies examine surveys with different gear, management, sectors and value. • Fishery-independent surveys must be cost effective to ensure that they endure. • Survey development should be part of co-management and management arrangements. [ABSTRACT FROM AUTHOR]