Eriko Hoshino

Management strategy evaluation: a powerful tool for conservation?

The poor management of natural resources has led in many cases to the decline and extirpation of populations. Recent advances in fisheries science could revolutionize management of harvested stocks by evaluating management scenarios in a virtual world by including stakeholders and by assessing its robustness to uncertainty. These advances have been synthesized into a framework, management strategy evaluation (MSE), which has hitherto not been used in terrestrial conservation. We review the potential of MSE to transform terrestrial conservation, emphasizing that the behavior of individual harvesters must be included because harvester compliance with management rules has been a major challenge in conservation. Incorporating resource user decision-making required to make MSEs relevant to terrestrial conservation will also advance fisheries science.

Modelling marine community responses to climate-driven species redistribution to guide monitoring and adaptive ecosystem-based management.

As a consequence of global climate-driven changes, marine ecosystems are experiencing polewards redistributions of species - or range shifts - across taxa and throughout latitudes worldwide. Research on these range shifts largely focuses on understanding and predicting changes in the distribution of individual species. The ecological effects of marine range shifts on ecosystem structure and functioning, as well as human coastal communities, can be large, yet remain difficult to anticipate and manage. Here, we use qualitative modelling of system feedback to understand the cumulative impacts of multiple species shifts in south-eastern Australia, a global hotspot for ocean warming. We identify range-shifting species that can induce trophic cascades and affect ecosystem dynamics and productivity, and evaluate the potential effectiveness of alternative management interventions to mitigate these impacts. Our results suggest that the negative ecological impacts of multiple simultaneous range shifts generally add up. Thus, implementing whole-of-ecosystem management strategies and regular monitoring of range-shifting species of ecological concern are necessary to effectively intervene against undesirable consequences of marine range shifts at the regional scale. Our study illustrates how modelling system feedback with only limited qualitative information about ecosystem structure and range-shifting species can predict ecological consequences of multiple co-occurring range shifts, guide ecosystem-based adaptation to climate change and help prioritise future research and monitoring.

A quantitative metric to identify critical elements within seafood supply networks

A theoretical basis is required for comparing key features and critical elements in wild fisheries and aquaculture supply chains under a changing climate. Here we develop a new quantitative metric that is analogous to indices used to analyse food-webs and identify key species. The Supply Chain Index (SCI) identifies critical elements as those elements with large throughput rates, as well as greater connectivity. The sum of the scores for a supply chain provides a single metric that roughly captures both the resilience and connectedness of a supply chain. Standardised scores can facilitate cross-comparisons both under current conditions as well as under a changing climate. Identification of key elements along the supply chain may assist in informing adaptation strategies to reduce anticipated future risks posed by climate change. The SCI also provides information on the relative stability of different supply chains based on whether there is a fairly even spread in the individual scores of the top few key elements, compared with a more critical dependence on a few key individual supply chain elements. We use as a case study the Australian southern rock lobster Jasus edwardsii fishery, which is challenged by a number of climate change drivers such as impacts on recruitment and growth due to changes in large-scale and local oceanographic features. The SCI identifies airports, processors and Chinese consumers as the key elements in the lobster supply chain that merit attention to enhance stability and potentially enable growth. We also apply the index to an additional four real-world Australian commercial fishery and two aquaculture industry supply chains to highlight the utility of a systematic method for describing supply chains. Overall, our simple methodological approach to empirically-based supply chain research provides an objective method for comparing the resilience of supply chains and highlighting components that may be critical.

Towards a diagnostic approach to climate adaptation for fisheries

A diagnostic approach to climate change adaptation for fisheries is proposed to define potential climate adaptation pathways in well-managed fisheries. Traditional climate vulnerability and risk assessments tend to focus on biophysical threats and opportunities and thereby what needs to be done to adapt to climate change. Our diagnostic approach moves from such analysis to focus on how the processes of adaptation and development of adaptive capacity can be structured to achieve desired outcomes. Using a well-grounded framework, the diagnostic approach moves from system description to characterization of challenges and opportunities, through two stages of analysis and validation, to the definition and embedding of adaptation options and pathways. The framework can include all contextually relevant variables and accommodate evaluation of adaptation outcomes and comparisons across scales and contexts. Such an approach can serve as a basis for enabling stakeholders to identify challenges and opportunities, and to explore and prioritize options for development and implementation of legitimate adaptation pathways.

A Bayesian belief network model for community-based coastal resource management in the Kei Islands, Indonesia

Understanding the specific relationships between ecological and socioeconomic conditions and marine tenure is likely to contribute to successful functioning of self-governance institutions for common-pool resources. Complex interrelationships of factors influencing fishing activities of coastal communities and implementation of customary marine tenure over their waters can be represented in a Bayesian belief network model. We developed a Bayesian belief network model that includes the links between factors for fishing communities in the Kei Islands in Indonesia, based on indepth local surveys. Our results showed that the cumulative impacts of multiple factors on key social, economic, and environmental outcomes can be much larger than the impact from a single source, which implies that management or policy intervention could be more effective when addressing multiple factors simultaneously. The local communitys perception of fish stock abundance trends was the single most important factor influencing social, economic, and environmental outcomes of their community-based management system. The frequency of which outsiders were sighted in territorial waters was strongly (negatively) linked to weak or strong implementation of a customary tenure (Sasi) and the occurrence of intervillage and intravillage conflict. Ecological variables also drive these conflicts, which illustrates the close connection between ecological and social outcomes, and the importance of considering social-ecological systems as a whole.

Examining the Long-Run Relationship between the Prices of Imported Abalone in Japan

ABSTRACT The rapid increase in production and trade of farmed abalone products is a presumed threat to wild abalone producing industries due to downward pressure on price. This article explores the long-run relationship and price dynamics of Australian wild-harvested abalone and other abalone imported into the Japanese market within a cointegration framework. Market integration is identified among fresh abalone products from six countries, with fairly stable relative prices, suggesting that Japanese consumers have a low level of product differentiation on the basis of origin. Consumers in the Japanese market are likely to willingly substitute between wild and farmed import product, placing continued pressure on price for Australian wild-harvested abalone suppliers into this market. A challenge for producers of wild-harvested product is the development of marketing strategies to build product differentiation and greater demand for wild products. JEL Codes: Q21, Q22, Q27, Q28.

Why model assumptions matter for natural resource management: interactions between model structure and life histories in fishery models

1. Bioeconomic models are increasingly used to provide benchmarks for harvest levels in wildlife and natural resource management, yet uncertainties related to model structure are underexplored. We investigate the importance of a range of uncertainties with a focus on model structure and life histories when estimating bioeconomic target reference point (TRPs) and assess the policy implications of ignoring these uncertainties. 2. We use three contrasting case studies to investigate the interactions between model, observational and process errors related to life-history parameters: the short-lived Japanese common squid Todarodes pacificus and Pacific saury Cololabis saira, and the slow-growing Patagonian toothfish Dissostichus eleginoides. We developed a simulation framework to test the harvest strategies resulting from bioeconomic TRPs under various assumptions about model structures and parameters. 3. We found the relative importance of different types of uncertainties affecting precision and accuracy of the model outputs varied according to the life-history traits. Little difference in TRP estimates was found between simple vs. complex population models for saury, while large differences were found for toothfish. The assumptions made about stock structure for squid not only resulted in different TRP estimates (generally, smaller for the multistock models), but also different economic outcomes depending on the balance of effort allocation between stocks. 4. Synthesis and applications. We use models similar to those used in the actual management of three case study species to explore the effects of interacting uncertainties on the management advice. We show that the interactions between structural elements of the models lead to very different management advice, depending on the life history of the species concerned. For the long-lived toothfish, life-history and gear selectivity parameters interacted strongly. For the short-lived squid which is managed as two stocks, spatial fishing effort allocation, correlation of environmental drivers between stocks and differential stock productivity interacted, producing very poor economic performance if assumptions about stock structure are incorrect. The key message for model-based natural resource management is that it is vital to investigate the major uncertainties related to model structure, process and estimation errors simultaneously, because they interact to produce non-intuitive results.

Estimating maximum economic yield in multispecies fisheries: a review

Fisheries can generate substantial economic returns to society if managed with economic targets as the main objective, that is with biomass, catch, and effort levels that correspond to maximum economic yield (MEY), although the move to such targets presents a number of challenges. These are compounded in multispecies fisheries, as it is not possible to achieve all individual targets simultaneously if targets are set on a species-by-species basis. Identifying appropriate targets both conceptually and empirically has also proven challenging, and consequently the implementation of economic targets to real world fisheries have been limited to a small number of data-rich and high-valued fisheries, with reliance on proxy target reference points in other fisheries. Moreover, these application has been limited due to unknowns as to what proxies should be used under different circumstances. Here, we review the alternative ways in which MEY has been estimated and applied in multispecies fisheries. We also review the roles and potential use of proxy target reference points for multispecies MEY in data-limited fisheries, building on Australian’s experience in implementing such a policy.