Catch allocation in a shared fishery with a minimally managed recreational sector

A prevalent problem in shared fisheries is competition between commercial and recreational fishers for access to a resource that is subject to increasing utilisation pressure. For most shared fisheries in New Zealand, the commercial sector is efficiently managed with a regime of individual transferable quota (ITQ), but the recreational fishing is only minimally managed. A model is developed that can be used to explore the size of the total allowable catch (TAC) that is both sustainable AND maximises the value to the NZ economy of the combined commercial and recreational catch when the commercial catch is regulated via a total allowable commercial catch (TACC) while the recreational catch (RC) is self regulating. Determinants of the optimal catch allocation include: • the relative size of annual value to recreational fishers vis-à-vis the value of one unit of ACE to the commercial fishing sector from a unit decrease in the TACC • the relation between value to recreational fishers and size of stock biomass • the biology, and in particular the population dynamics of the fishery • the nature of the functional relationship between the self regulating recreational catch and stock biomass. The model can be applied to a fishery of interest by quantifying the above variables and relationships.economics management shared fishery catch allocation, Resource /Energy Economics and Policy,

Out of the pot and into the money: Managing the Western Rock Lobster Fishery by ITE's or ITQ's?

The West Coast Rock Lobster fishery is Australia's most valuable commercial fishery. Around 550 vessels harvest an average of 10,500 tonnes of lobster per annum. The industry has an enviable track record of biological management based on a variety of input controls, although three significant pot reduction interventions have been necessary in recent years. An evaluation of a range of possible future management regimes is reported in this paper. The results were derived from a purpose built bio-economic model three separate biological zones in the fishery using non linear optimization to produce ten year steady state solutions for alternative management options. Management options included the current pot control system, and versions of variable transferable catch quota. Key outputs for each scenario include: net economic benefits, breeder biomass index, annual catch, annual pot lifts, number of pots and vessel numbers. The results indicate significant potential net economic gains from moving away from the current input control regime. The range of scenarios modelled illustrated some of the tradeoffs between maximising net economic returns and minimizing biological risks, as well as quantifying the impact of changes such as improved pot design and extended fishing seasons. The results will inform consideration by the industry about a possible new management system.rock lobster, quotas, ITQs, Western Australia, bioeconomic, economic benefits, Resource /Energy Economics and Policy,

Valuing Biodiversity in Life Cycle Impact Assessment

Erratum published on 13 March 2020, see Sustainability 2020, 12(6), 2270. https://doi.org/10.3390/su11205628In this article, the authors propose an impact assessment method for life cycle assessment (LCA) that adheres to established LCA principles for land use-related impact assessment, bridges current research gaps and addresses the requirements of different stakeholders for a methodological framework. The conservation of biodiversity is a priority for humanity, as expressed in the framework of the Sustainable Development Goals (SDGs). Addressing biodiversity across value chains is a key challenge for enabling sustainable production pathways. Life cycle assessment is a standardised approach to assess and compare environmental impacts of products along their value chains. The impact assessment method presented in this article allows the quantification of the impact of land-using production processes on biodiversity for several broad land use classes. It provides a calculation framework with degrees of customisation (e.g., to take into account regional conservation priorities), but also offers a default valuation of biodiversity based on naturalness. The applicability of the method is demonstrated through an example of a consumer product. The main strength of the approach is that it yields highly aggregated information on the biodiversity impacts of products, enabling biodiversity-conscious decisions about raw materials, production routes and end user products

Parafermionic conformal field theory on the lattice

Finding the precise correspondence between lattice operators and the continuum fields that describe their long-distance properties is a largely open problem for strongly interacting critical points. Here we solve this problem essentially completely in the case of the three-state Potts model, which exhibits a phase transition described by a strongly interacting 'parafermion' conformal field theory. Using symmetry arguments, insights from integrability, and extensive simulations, we construct lattice analogues of nearly all the relevant and marginal physical fields governing this transition. This construction includes chiral fields such as the parafermion. Along the way we also clarify the structure of operator product expansions between order and disorder fields, which we confirm numerically. Our results both suggest a systematic methodology for attacking non-free field theories on the lattice and find broader applications in the pursuit of exotic topologically ordered phases of matter.Comment: 27 pages, 4 figures; v2 added reference

Heterologous expression system comprising a b. subtilis promoter

The present invention relates to expression cassettes suitable for the expression of a heterologous gene. Furthermore, the invention relates to recombinant plasmids comprising such expression cassettes. Also, the invention relates to host cells comprising such cassettes or plasmids. Another embodiment relates to promoters for use in an expression cassette and in heterologous expression systems. Finally, an embodiment relates to methods for the expression of a heterologous gene.<br/

Functional neurochemical imaging of the human striatal cholinergic system during reversal learning

Animal studies have shown that acetylcholine (ACh) levels in the dorsal striatum play a role in reversal learning. However, this has not been studied in humans due to a lack of appropriate non-invasive techniques. Proton magnetic resonance spectroscopy (1H-MRS) can be used to measure metabolite levels in humans in vivo. Although it cannot be used to study ACh directly, 1H-MRS can be used to study choline, an ACh precursor which is linked to activity-dependent ACh release. The aim of this study was to use functional-1H-MRS (fMRS) to measure changes in choline levels in the human dorsal striatum during performance of a probabilistic reversal learning task. We demonstrate a task-dependent decrease in choline, specifically during reversal, but not initial, learning. We interpret this to reflect a sustained increase in ACh levels, which is in line with findings from the animal literature. This task-dependent change was specific to choline and was not observed in control metabolites. These findings provide support for the use of fMRS in the in vivo study of the human cholinergic system

Biological Cybernetics: 60 years and more to come

Projekt DEALPeer Reviewe

Biologische Vielfalt in Ökobilanzen verankern

Akteure der öffentlichen Hand sowie der Wirtschaft benötigen Instrumente, mit denen sie die Wirkung ihrer Tätigkeit auf die biologische Vielfalt steuern können. Dabei muss der Blick auf ganze Wertschöpfungsketten gelegt werden. Eine neue Methode setzt hier an und ermöglicht die Abbildung der biologischen Vielfalt in Ökobilanzen

Regional striatal cholinergic involvement in human behavioural flexibility

Animal studies have shown that the striatal cholinergic system plays a role in behavioural flexibility but, until recently, this system could not be studied in humans due to a lack of appropriate non-invasive techniques. Using proton magnetic resonance spectroscopy (1H-MRS) we recently showed that the concentration of dorsal striatal choline (an acetylcholine precursor) changes during reversal learning (a measure of behavioural flexibility) in humans. The aim of the present study was to examine whether regional average striatal choline was associated with reversal learning. 36 participants (mean age = 24.8, range = 18-32, 20 female) performed a probabilistic learning task with a reversal component. We measured choline at rest in both the dorsal and ventral striatum using 1H-MRS. Task performance was described using a simple reinforcement learning model that dissociates the contributions of positive and negative prediction errors to learning. Average levels of choline in the dorsal striatum were associated with performance during reversal, but not during initial learning. Specifically, lower levels of choline in the dorsal striatum were associated with a lower number of perseverative trials. Moreover, choline levels explained inter-individual variance in perseveration over and above that explained by learning from negative prediction errors. These findings suggest that the dorsal striatal cholinergic system plays an important role in behavioural flexibility, in line with evidence from the animal literature and our previous work in humans. Additionally, this work provides further support for the idea of measuring choline with 1H-MRS as a non-invasive way of studying human cholinergic neurochemistr