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Fisheries based on short lived species are notoriously difficult to manage using traditional effort or catch quota controls. Such fisheries are often characterised by high fecundity, requiring only a small spawning stock to potentially produce a large biomass the following year. This stock, or at least its availability, is driven by unpredictable environmental conditions to a large extent, with the available biomass depleted over the fishing season though both natural and fishing mortality. In most instances, management of these fisheries has focused on ensuring sufficient escapement at the end of the season to allow sufficient recruitment the following year. Catch-rate triggers are one such management tool to determine when fishing should cease. In this study, the use of such triggers in the banana prawn sub-fishery of the Australian Northern Prawn Fishery are assessed. The fishery has an explicit objective of achieving maximum economic yield, and the triggers are set on an economic basis during the season based on price and cost information provided by the industry. The in-season estimates provided by industry were highly correlated with information derived retrospectively through an economic survey, with the industry-provided estimates generally resulting in a more conservative (i.e., higher) break-even catch-rate level. It is the profit maximising behaviour of the fishers, however, that results in the greatest benefits, with most boats leaving the fishery before the trigger catch-rate is reached. The catch-rate trigger operates more as a "safety-net" for the fishery, and possibly a nudge encouraging vessels to maximise their profits given their individual cost structures. [ABSTRACT FROM AUTHOR]

Increasingly, stock assessments for hard-to-age species such as crabs, prawns, rock lobsters, and abalone are being based on integrated size-structured population dynamics models that are fit to a variety of data sources. These data sources include tagging data to inform growth. Diagnostic statistics and plots have been developed to explore how well integrated population models fit the data types typically used for assessment purposes (index data, size- and age-compositions, and conditional age-at-length data). However, such statistics and plots are not available for tagging data, when these data are used to estimate growth. This paper outlines two diagnostic statistics that can be used to evaluate fits to tagging data, and develops a method based on ‘Francis weighting’ for weighting tagging data in integrated models. For illustration, the methods are applied to Aleutian Islands golden king crab ( Lithodes aequispinus ) in Alaska, and tiger prawns ( Penaeus semisulcatus and P . esculentus ) in Australia's Northern Prawn Fishery. Some degree of growth model mis-specification was revealed for P . semisulcatus , and there were conflicts in the data for the tiger prawns. The standard errors for the estimates of mature male biomass for golden king crab were larger when the tagging data were downweighted based on the proposed weighting method. This serves to emphasise that assessments and their interpretations can be impacted by how tagging data are weighted. [ABSTRACT FROM AUTHOR]

Most of the stock assessments conducted in the USA and in New Zealand are based on packages that have been developed for generic use, are well documented, and have been tested using simulation. However, this is not the case for assessments conducted in Australia and many other countries. This paper reviews all of the model-based stock assessments for Australian fisheries to evaluate how many of these assessments could have been conducted using the publicly-available stock assessment packages used widely in the USA and New Zealand. The 76 model-based assessments reflect 37% of the 2013 catch recorded in Australia's Status for Key Australian Fish Stocks Reports (or 34% of the total catch in 2013). All but 18 (or 24 if full rather than approximate age-size-structured models need to be used) of the stock assessments could have been conducted using stock assessment packages used in the United States and New Zealand. Adoption and use of packages for more stocks in Australia should increase the likelihood that results are based on correctly-coded models whose estimation performance is widely understood, reduce the time needed to conduct assessments, and speed up the peer-review process. The availability of training, manuals, and example data sets for stock assessment packages should partially address their additional complexity. Additional benefits, in terms of numbers of assessed stocks, could occur if Australian stock assessment scientists develop a forum to collaborate and share methods. These results are applicable to many other jurisdictions that undertake stock assessments. [ABSTRACT FROM AUTHOR]

Stock assessments provide scientific advice in support of fisheries decision making. Ideally, assessments involve fitting population dynamics models to fishery and monitoring data to provide estimates of time-trajectories of biomass and fishing mortality in absolute terms and relative to biological reference points such as B MSY and F MSY , along with measures of uncertainty. Some stock assessments are conducted using software developed for a specific stock or group of stocks. However, increasingly, stock assessments are being conducted using packages developed for application to several taxa and across multiple regions. We review the range of packages used to conduct assessments of fish and invertebrate stocks in the United States because these assessments tend to have common goals, and need to provide similar outputs for decision making. Sixteen packages are considered, five based on surplus production models, one based on a delay-difference model, and the remainder based on age-structured models. Most of the packages are freely available for use by analysts in the US and around the world, have been evaluated using simulations, and can form the basis for forecasts. The packages differ in their ease of use and the types of data inputs they can use. This paper highlights the benefits of stock assessment packages in terms of allowing analysts to explore many assessment configurations and facilitating the peer-review of assessments. It also highlights the disadvantages associated with the use of packages for conducting assessments. Packages with the most options and greatest flexibility are the most difficult to use, and see the greatest development of auxiliary tools to facilitate their use. [ABSTRACT FROM AUTHOR]

Defining goals and objectives is a critical component of adaptive management of natural resources because they provide the basis on which management strategies can be designed and evaluated. The aims of this study are: (i) to apply and test a collaborative method to elicit goals and objectives for inshore fisheries and biodiversity in the coastal zone of a regional city in Australia; (ii) to understand the relative importance of management objectives for different community members and stakeholders; and (iii) to understand how diverse perceptions about the importance of management objectives can be used to support multiple-use management in Australia’s iconic Great Barrier Reef. Management goals and objectives were elicited and weighted using the following steps: (i) literature review of management objectives, (ii) development of a hierarchy tree of objectives, and (iii) ranking of management objectives using survey methods. The overarching goals identified by the community group were to: (1) protect and restore inshore environmental assets; (2) improve governance systems; and (3) improve regional (socio-economic) well-being. Interestingly, these goals differ slightly from the usual triple-bottom line objectives (environmental, social and economic) often found in the literature. The objectives were ranked using the Analytical Hierarchical Process, where a total of 141 respondents from industry, government agencies, and community from across Queensland State undertook the survey. The environment goal received the highest scores, followed by governance and lastly well-being. The approach to elicit and rank goals and objectives developed in this study can be used to effectively support coastal resource management by providing opportunities for local communities to participate in the setting of regional objectives. [ABSTRACT FROM AUTHOR]

Effective publicly developed adaptation strategies are crucial in managing the impacts of Climate Change. Adaptation strategy development is particularly complex in estuarine and coastal marine ecosystems because of their diverse environmental values, extensive human utilisation and the complex socio-ecological systems they support. Although many generic adaptation frameworks are available they cannot provide specific guidance for locally relevant strategy development. In contrast, situation-specific tools work well for their intended purpose but are usually unsuitable for a different situation. The gap between generic frameworks and situation-specific tools is addressed in this study by developing a set of general principles to provide guidance for the efficient and robust development of adaptation strategies. The nine principles comprise a conceptualisation of the various factors that are likely to have an effect on the success or otherwise of an adaptation strategy and they apply in any situation. An example ‘adaptation checklist’ that serves as a guide to practitioners in the field, will help ensure that all critical components are covered during the development of an adaptation strategy. [ABSTRACT FROM AUTHOR]

Stakeholder engagement is important for successful management of natural resources, both to make effective decisions and to obtain support. However, in the context of coastal management, questions remain unanswered on how to effectively link decisions made at the catchment level with objectives for marine biodiversity and fisheries productivity. Moreover, there is much uncertainty on how to best elicit community input in a rigorous manner that supports management decisions. A decision support process is described that uses the adaptive management loop as its basis to elicit management objectives, priorities and management options using two case studies in the Great Barrier Reef, Australia. The approach described is then generalised for international interest. A hierarchical engagement model of local stakeholders, regional and senior managers is used. The result is a semi-quantitative generic elicitation framework that ultimately provides a prioritised list of management options in the context of clearly articulated management objectives that has widespread application for coastal communities worldwide. The case studies show that demand for local input and regional management is high, but local influences affect the relative success of both engagement processes and uptake by managers. Differences between case study outcomes highlight the importance of discussing objectives prior to suggesting management actions, and avoiding or minimising conflicts at the early stages of the process. Strong contributors to success are a) the provision of local information to the community group, and b) the early inclusion of senior managers and influencers in the group to ensure the intellectual and time investment is not compromised at the final stages of the process. The project has uncovered a conundrum in the significant gap between the way managers perceive their management actions and outcomes, and community's perception of the effectiveness (and wisdom) of these same management actions. [ABSTRACT FROM AUTHOR]

Governance has long been identified as a crucial part of solving environmental problems. Effective governance supports and encourages adaptive capacity to maintain or improve the conditions of socio-ecological systems. As coastal zones are among the most vulnerable systems to climate change impacts (e.g. sea-level rise), the adaptive capacity of coastal communities to climate change threats will be critical. Human populations will respond both directly and indirectly to these threats and impacts; for instance by adapting resource use and practices (e.g. changing fish targets). In this paper, we apply definitions of resilience, adaptive capacity and vulnerability to the coastal zone socio-ecological system. We focus on organizations and management aspects of governance in coastal Australia. Our approach combines a literature review that highlights key organizational drivers that supports adaptive capacity with interview data from senior resource managers from organizations from across Australia to test the validity of such drivers. The key drivers related to organizational and management issues that are required to build and strengthen the adaptive capacity of Australian coastal communities are: (a) Leadership; (b) Clear responsibilities and flexible organizational framework; (c) Effective integration of knowledge and insights; (d) Learning approach to natural resource management; and (e) Human capacity and coordinated participation in decision-making. Our study showed that natural resource management organizations are clearly concerned about future changes and uncertainties and recognize the need for cooperation and good organizational drivers. However, integration of knowledge and long-term planning to deal with predicted changes in climate is largely lacking; and mismatches between management, organizational and ecosystem boundaries and processes also exist. [ABSTRACT FROM AUTHOR]

Abstract: A framework is described whereby effort levels and their associated catches consistent with maximizing the net present value (NPV) of fishery profits over time can be calculated when each harvested species is modelled using a different population dynamics model. Results are presented based on three species (Penaeus semisulcatus, P. esculentus, and Metapenaeus endeavouri) in Australia''s Northern Prawn Fishery and three population dynamics models (size-structured, delay-difference, and biomass dynamics). The results indicate that there is a considerable between-model variation in key model outputs such as the catch predicted for 2010 and the estimated future long-term catches corresponding to maximum economic yield. This variation is comparable with that due to uncertainty about economic parameters when all species are modelled using a size-structured population dynamics model, highlighting the importance of both good population dynamics models and accurate economic parameter inputs. The results also highlight some of the implications (in terms of estimating effort and catch levels which maximize NPV) of not having sufficient data when using population dynamics models to explicitly represent some of the species caught in a multi-species fishery. [Copyright &y& Elsevier]

• A web-based tool collating freely available stock assessment packages. • Packages divided into 10 assessment classes. • Packages evaluated whether state-of-the-art within class. • Full specifications provided in a consistent manner. • Test data and instructions for some packages. Stock assessments are integral to fisheries management, and the demand for stock assessments based on population dynamics models continues to increase. Historically, stock assessments have been based on bespoke methods and software. There is now a trend towards the use of flexible, documented, tested and maintained software packages, because use of such packages increases efficiency and consistency in assessments and should lead to more reliable and repeatable assessment outcomes. We have developed a web-site that collates available stock assessment packages (from data-limited to -rich) to provide assessment analysts with a single platform that summarizes the features of the available packages in a consistent manner. We also highlight current state-of-the-art packages, and those that are no longer supported or have been superseded. In addition to providing the packages, the web-site facilitates users of packages to provide feedback to developers regarding which features of other packages could be included in future versions of their packages. We see this effort as a way to support the design of the next generation stock assessment package. [ABSTRACT FROM AUTHOR]

The Northern Prawn Fishery (NPF) is one of Australia's most valuable federally managed fisheries. It has also been a focus for modelling in Australia, with over 40 years of development of bioeconomic, stock assessment and management strategy evaluation models that have been used to varying degrees to inform management. The current management model has been in operation for over 10 years and is used to set the total allowable effort (TAE) for the tiger prawn (Penaeus semisulcatus and P. esculentus) component of the fishery, historically undertaken after a mid-year closure. The success of management has resulted in increased stocks of tiger prawns, and a fishery before the mid-year closure during which fishing for banana prawns was historically the main activity. While the current management model includes the consequences of fishing for tiger prawns during the first season in terms of which weeks are available for fishing for tiger prawns when estimating the TAE, the lack of explicit inclusion of banana prawns in the bioeconomic modelling has resulted in concerns that the TAE may be biased, as effort is allocated in the model to tiger prawns that, in reality, should be applied to banana prawns. The current model was consequently extended to include an explicit banana prawn component, and a range of scenarios undertaken to explore the impact of this on the management advice. It was found that the current model overestimates the optimal level of effort to be applied to tiger prawns except during periods of very low banana prawn abundance. Banana prawns, which vary substantially inter-annually due largely to environmental drivers, were also found to be the key driver of the level of overall fishery profit, suggesting that greater attention to this component of the fishery may be necessary to achieve the objective of maximizing net economic returns from the NPF. [ABSTRACT FROM AUTHOR]

• Fisheries stock-recruitment specification has important management implications. • Sensitivity of management reference points should be tested or dynamic form used. • Explicit inclusion of environmental correlates needs rigorous assessment. • Harvest Control Rules effectively evaluate robustness to recruitment variability. • Empirical rules with survey inputs circumvents needing mechanistic understanding. The representation and parameterisation of the stock-recruitment relationship is highly influential in fisheries stock assessments. We overview important management implications arising from choices and assumptions made when modelling recruitment and propose pragmatic solutions. An age-structured population model is used to highlight some additional considerations including (1) incorrect assumptions about the source of recruits and (2) ways to account for environmental correlates in stock assessment models, either directly or indirectly. Existing stationary approaches ignore the sometimes considerable influence of the environment on population processes such as recruitment, growth and mortality, all of which are expected to shift under changing climate. We show that where environmental relationships are explicitly included in models, they need to be rigorously assessed and model parameterization carefully evaluated. Variability in annual recruitment estimates (specified by the standard deviation σ R) must be adjusted to control the partitioning of total variation into environmental and unexplained variation, as reference point estimates are particularly sensitive to the choice of σ R. Finally, we evaluate two recommended solutions to these issues: Harvest Control Rules (HCRs) that are robust to recruitment uncertainty and variability, and empirical HCRs that use pre-season survey inputs as a way to more directly provide forecasts without needing to quantify the complex underlying details of the environmental-recruitment relationships. [ABSTRACT FROM AUTHOR]

• Redleg banana prawns are caught in a remote part of the northern prawn fishery. • Fishing effort on the species has varied considerably in recent years. • We model the key drivers of fishing effort on the sub-fishery. • We find that economic conditions in the main part of the fishery is a key driver. Recent low levels of fishing effort in the redleg banana prawn (Penaeus indicus) component of the Australian Northern Prawn Fishery have highlighted challenges in assessing the stock status of the species and deriving appropriate management responses. Usually, low levels of fishing effort are associated with low stock abundance, but economic factors also affect fishing activity. In this study, we consider the key drivers of fishing effort in the sub-fishery, and conclude that fishing effort is driven by expectations of catch based on environmental drivers, realised revenue per unit of fishing effort, and the opportunity cost of fishing in other areas. In the case of the recent low effort levels, it is the opportunity cost that has been most influential, highlighting the importance of considering economic drivers when managing fisheries. [ABSTRACT FROM AUTHOR]