An integrated description of the respiratory system of the abalone Haliotis iris is presented. These animals are believed to be inherently primitive and still bear the ancestral gastropod gill arrangement, thus allowing physiological examination of a 'living fossil'. Ventilation, gaseous diffusion, blood transport and the anatomical arrangement of the vascular system are examined under a range of conditions. Resting H. iris consume an average of 0.47 µmol 0₂.g live weight⁻¹ .h⁻¹, 87% of which is taken up across the gills, the remainder diffuses directly into the foot and epipodium. A 300g abalone ventilates its gills at a rate of 28mL.min⁻¹, a rate which, due to low resistance to diffusion (diffusion limitation index = 0.47) and a well matched ventilation/perfusion conductance ratio, is adequate to support the quiescent animal. Increased oxygen demand is accommodated by an increase in cardiac stroke volume, elevating output from 9.1 to 24.4 µL.g⁻¹.min⁻¹. At rest the right gill is the predominant gas exchanger, receiving 95.7% of the branchial blood flow, when cardiac output is elevated the left gill becomes equally perfused, effectively doubling the diffusing surface. Ventilation does not increase, and an increased reliance on assistance from external water currents is seen. Previously undescribed components of the vascular system, notably an extensive sinus of mixed venous and arterial blood surrounding the gut and a large vessel that offers a bypass to the right kidney, provide a low resistance circuit between the heart and gills, bypassing the major organs and muscles. The low resistance circuit allows haemolymph to pass from the aorta to the base of the gills with minimal loss of pressure and no phase shift in the pulse, allowing blood to cross the gills with maximal inertia and instantaneous pressure gradient. Haliotis iris therefore appears to have exploited its limited physiological resources to the maximum in the routine operation of its gas exchange system. It is concluded that further improvement could not occur without substantial remodeling of the body plan, which may account for the abandonment of the system by higher gastropods.

An integrated description of the respiratory system of the abalone Haliotis iris is presented. These animals are believed to be inherently primitive and still bear the ancestral gastropod gill arrangement, thus allowing physiological examination of a 'living fossil'. Ventilation, gaseous diffusion, blood transport and the anatomical arrangement of the vascular system are examined under a range of conditions. Resting H. iris consume an average of 0.47 µmol 0₂.g live weight⁻¹ .h⁻¹, 87% of which is taken up across the gills, the remainder diffuses directly into the foot and epipodium. A 300g abalone ventilates its gills at a rate of 28mL.min⁻¹, a rate which, due to low resistance to diffusion (diffusion limitation index = 0.47) and a well matched ventilation/perfusion conductance ratio, is adequate to support the quiescent animal. Increased oxygen demand is accommodated by an increase in cardiac stroke volume, elevating output from 9.1 to 24.4 µL.g⁻¹.min⁻¹. At rest the right gill is the predominant gas exchanger, receiving 95.7% of the branchial blood flow, when cardiac output is elevated the left gill becomes equally perfused, effectively doubling the diffusing surface. Ventilation does not increase, and an increased reliance on assistance from external water currents is seen. Previously undescribed components of the vascular system, notably an extensive sinus of mixed venous and arterial blood surrounding the gut and a large vessel that offers a bypass to the right kidney, provide a low resistance circuit between the heart and gills, bypassing the major organs and muscles. The low resistance circuit allows haemolymph to pass from the aorta to the base of the gills with minimal loss of pressure and no phase shift in the pulse, allowing blood to cross the gills with maximal inertia and instantaneous pressure gradient. Haliotis iris therefore appears to have exploited its limited physiological resources to the maximum in the routine operation of its gas exchange system. It is concluded that further improvement could not occur without substantial remodeling of the body plan, which may account for the abandonment of the system by higher gastropods.

This cultural history of paua shell jewellery redresses the lack of visibility of such objects as a significant part of 20th century New Zealand material culture and provides a basis for a more balanced interpretation beyond its stereotyping as tourist kitsch. It questions why quality paua shell jewellery made before the late 1960s failed to gain recognition with most New Zealanders until fairly recently as anything other than tourist souvenirs. Over 1,500 items of paua shell jewellery, mainly in private collections, formed the basis for this multidisciplinary research project that incorporates historical, anthropological and material culture studies approaches to write a cultural history of such jewellery. The objects were photographed and where available, their provenance recorded. A visual analysis of the items - paying attention to details of design and construction - established various, often overlapping categories that facilitated the dating and identification process. Gradually, a picture of the production of paua shell jewellery over the decades emerged. The wider socio-cultural context was then built using archival sources, various publications, conversations with one-time industry representatives, and discussions with original owners of paua shell jewellery. Interpretation of the material established multiple roles for paua shell jewellery over the decades for various groups of people. Changes over time provided insights into aspects of identity creation by New Zealanders. Until the 1920s, the shell�s main role had been as a European applied arts material and as inlay for Maori woodcarvings. Paua shell as a commercial souvenir material developed during the Depression and was shaped by the interaction between an emerging nationalism and a democratising of travel in New Zealand. Paua shell native bird brooches functioned as affordable alternatives to greenstone souvenirs for the working-class tourists that began exploring their own country. In addition to its role as emblems of nationhood in the interwar years, paua shell jewellery had meaning as souvenirs for American servicemen stationed in New Zealand during the War, and as patriotic tokens for its own population due to its association with disabled servicemen. Paua shell jewellery functioned as acknowledgement of settlement for European immigrants in the post war era, and as travel memento for trans-Tasman tourists from the mid 1950s. New Zealand girls received paua shell items as first jewellery, and women wore it as dress or costume jewellery. Until the increase of tourism in the 1960s, paua shell jewellery had existed on a number of planes. The exploitation of paua shell by the tourist industry, however, upset the balance and its dominance as souvenir forced a retreat of alternative uses. Other than as tourist souvenir, paua shell jewellery became invisible to the local population. Their withdrawal from an association with paua shell as a cultural marker of national identity explains why so many New Zealanders were uncertain about liking or disliking paua shell jewellery until recently.

Marine reserves have increasingly been recognised for their potential to address the pervasive problem of unsustainable harvest of fisheries worldwide. Biologists advocate the benefits of increased spawning biomass, larger modal sizes and greater densities of fish within marine reserves, and the possibility of spillover to adjacent fishable areas. Bioeconomic studies, however, find that pay-offs from stand-alone marine reserves rarely compete with sustainable yield management schemes, but that they can be beneficial when stocks are heavily exploited. Most of these bioeconomic models are analytical and deterministic in nature, and therefore ignore the redistribution of effort in response to closure and the inherent uncertainty of the marine environment. We present a bioeconomic analysis of a network of no-take areas around Stewart Island in New Zealand applied to the shellfish species paua (abalone) that incorporates both predicted redistribution and reduction in effort, as well as stochastic recruitment. A nested logit model is applied to spatially recorded catch and effort data by the Ministry of Fisheries between 1998 and 2003 to capture the two level decision-making process of divers. On any given day, divers decide whether to go diving at all, and if so, which of the 16 statistical areas around Stewart Island to visit. Weather conditions, spatially varying levels of catch per unit of effort and distance are used as explanatory variables to select areas for closure according to the �least economic impact� in terms of loss of diving trips. An age-structured biological model is developed with parameters specifically applied to paua stocks around Stewart Island. Virgin paua biomass as of 1974 is estimated on the basis of growth, survival, post-larval recruitment and egg production in the absence of fishing. Historic catch rates are then applied to find overall and area-specific levels of exploitation rates, spawning biomass, egg production, legal biomass and numbers of paua. In a final step, the economic model is linked to the biological model to simulate the imposition of no-take areas when taking account of the initial disproportional shift of harvest to fished areas in the first year, and the increase in overall pressure on legal biomass in the years thereafter. We contribute to the marine reserve debate by showing that in the very long run, the overall yield under closure of a relatively small area approaches and even slightly surpasses the yield under no closure for an assumed spillover gradient of 40% despite the redistribution of effort. The most important benefits of marine reserves emerge when stochastic recruitment is included in the recruitment function. In practice, predictions about the stock status and the impact of different harvest levels become much more difficult when acknowledging the inherent variability of the marine environment. The likelihood of stock collapse depends on the assumed value of two recruitment parameters, which highlights the effects of parameter uncertainty and emphasizes the role of marine reserves for population persistence. We also show that under uncertainty average yields under a management regime of a network of no-take areas in addition to the quota system can equal yields under no closure for an assumed spillover gradient of 40%, despite the increased pressure on areas adjacent to the closed areas. Our findings have significant implications for the management of the paua fishery at Stewart Island. For a heterogeneously abundant species, such as paua, spatial management in addition to quota limits could be vital in ensuring the long-term sustainability of the fishery given the inherent variability of the marine environment.

This cultural history of paua shell jewellery redresses the lack of visibility of such objects as a significant part of 20th century New Zealand material culture and provides a basis for a more balanced interpretation beyond its stereotyping as tourist kitsch. It questions why quality paua shell jewellery made before the late 1960s failed to gain recognition with most New Zealanders until fairly recently as anything other than tourist souvenirs. Over 1,500 items of paua shell jewellery, mainly in private collections, formed the basis for this multidisciplinary research project that incorporates historical, anthropological and material culture studies approaches to write a cultural history of such jewellery. The objects were photographed and where available, their provenance recorded. A visual analysis of the items - paying attention to details of design and construction - established various, often overlapping categories that facilitated the dating and identification process. Gradually, a picture of the production of paua shell jewellery over the decades emerged. The wider socio-cultural context was then built using archival sources, various publications, conversations with one-time industry representatives, and discussions with original owners of paua shell jewellery. Interpretation of the material established multiple roles for paua shell jewellery over the decades for various groups of people. Changes over time provided insights into aspects of identity creation by New Zealanders. Until the 1920s, the shell�s main role had been as a European applied arts material and as inlay for Maori woodcarvings. Paua shell as a commercial souvenir material developed during the Depression and was shaped by the interaction between an emerging nationalism and a democratising of travel in New Zealand. Paua shell native bird brooches functioned as affordable alternatives to greenstone souvenirs for the working-class tourists that began exploring their own country. In addition to its role as emblems of nationhood in the interwar years, paua shell jewellery had meaning as souvenirs for American servicemen stationed in New Zealand during the War, and as patriotic tokens for its own population due to its association with disabled servicemen. Paua shell jewellery functioned as acknowledgement of settlement for European immigrants in the post war era, and as travel memento for trans-Tasman tourists from the mid 1950s. New Zealand girls received paua shell items as first jewellery, and women wore it as dress or costume jewellery. Until the increase of tourism in the 1960s, paua shell jewellery had existed on a number of planes. The exploitation of paua shell by the tourist industry, however, upset the balance and its dominance as souvenir forced a retreat of alternative uses. Other than as tourist souvenir, paua shell jewellery became invisible to the local population. Their withdrawal from an association with paua shell as a cultural marker of national identity explains why so many New Zealanders were uncertain about liking or disliking paua shell jewellery until recently.

Marine reserves have increasingly been recognised for their potential to address the pervasive problem of unsustainable harvest of fisheries worldwide. Biologists advocate the benefits of increased spawning biomass, larger modal sizes and greater densities of fish within marine reserves, and the possibility of spillover to adjacent fishable areas. Bioeconomic studies, however, find that pay-offs from stand-alone marine reserves rarely compete with sustainable yield management schemes, but that they can be beneficial when stocks are heavily exploited. Most of these bioeconomic models are analytical and deterministic in nature, and therefore ignore the redistribution of effort in response to closure and the inherent uncertainty of the marine environment. We present a bioeconomic analysis of a network of no-take areas around Stewart Island in New Zealand applied to the shellfish species paua (abalone) that incorporates both predicted redistribution and reduction in effort, as well as stochastic recruitment. A nested logit model is applied to spatially recorded catch and effort data by the Ministry of Fisheries between 1998 and 2003 to capture the two level decision-making process of divers. On any given day, divers decide whether to go diving at all, and if so, which of the 16 statistical areas around Stewart Island to visit. Weather conditions, spatially varying levels of catch per unit of effort and distance are used as explanatory variables to select areas for closure according to the �least economic impact� in terms of loss of diving trips. An age-structured biological model is developed with parameters specifically applied to paua stocks around Stewart Island. Virgin paua biomass as of 1974 is estimated on the basis of growth, survival, post-larval recruitment and egg production in the absence of fishing. Historic catch rates are then applied to find overall and area-specific levels of exploitation rates, spawning biomass, egg production, legal biomass and numbers of paua. In a final step, the economic model is linked to the biological model to simulate the imposition of no-take areas when taking account of the initial disproportional shift of harvest to fished areas in the first year, and the increase in overall pressure on legal biomass in the years thereafter. We contribute to the marine reserve debate by showing that in the very long run, the overall yield under closure of a relatively small area approaches and even slightly surpasses the yield under no closure for an assumed spillover gradient of 40% despite the redistribution of effort. The most important benefits of marine reserves emerge when stochastic recruitment is included in the recruitment function. In practice, predictions about the stock status and the impact of different harvest levels become much more difficult when acknowledging the inherent variability of the marine environment. The likelihood of stock collapse depends on the assumed value of two recruitment parameters, which highlights the effects of parameter uncertainty and emphasizes the role of marine reserves for population persistence. We also show that under uncertainty average yields under a management regime of a network of no-take areas in addition to the quota system can equal yields under no closure for an assumed spillover gradient of 40%, despite the increased pressure on areas adjacent to the closed areas. Our findings have significant implications for the management of the paua fishery at Stewart Island. For a heterogeneously abundant species, such as paua, spatial management in addition to quota limits could be vital in ensuring the long-term sustainability of the fishery given the inherent variability of the marine environment.