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Hashimoto Y.,Tokyo University of Agriculture and Technology | Takamoto A.,Tokyo University of Agriculture and Technology | Kikkawa R.,Mie University | Murakami K.,Fisheries | Yamaguchi N.,Japan National Institute for Agro - Environmental Sciences
Environmental Science and Technology | Year: 2014

Little is known about how the solubility and chemical speciation of phosphorus (P) in poultry litters are altered during the composting period. This study investigated the quantitative and qualitative changes in organic P (Po) and inorganic P (Pi) compositions in poultry litters during the seven-day composting period using sequential extraction in combination with P K-edge X-ray absorption near-edge structure (XANES) and solution 31P nuclear magnetic resonance (NMR) spectroscopy. The result of sequential extraction illustrated that the significant decrease of H2O-P by 55% in poultry litters occurred concomitantly with the increase of HCl-Pi and HCl-Po during the composting period (p < 0.05). X-ray diffraction results for poultry litter samples showed three distinct peaks indicative of hydroxyapatite. Phosphorus K-edge XANES confirmed the increase of hydroxyapatite during the composting period, corresponding to the increase of HCl-Pi determined by the sequential extraction. The NaOH-EDTA extraction for solution 31P NMR revealed that myo-inositol hexakisphosphate (IHP) constituted about 80% of phosphate monoesters and was increased from 16 to 28% in the poultry litter during the composting period. The combined applications of chemical extraction and molecular-spectroscopic techniques determined that water-soluble P in poultry litter was transformed into less soluble phases, primarily hydroxyapatite and IHP, during the composting period. © 2014 American Chemical Society. Source

Pons M.,University of Washington | Branch T.A.,University of Washington | Melnychuk M.C.,University of Washington | Jensen O.P.,Rutgers University | And 11 more authors.
Fish and Fisheries | Year: 2016

Commercial tunas and billfishes (swordfish, marlins and sailfish) provide considerable catches and income in both developed and developing countries. These stocks vary in status from lightly exploited to rebuilding to severely depleted. Previous studies suggested that this variability could result from differences in life-history characteristics and economic incentives, but differences in exploitation histories and management measures also have a strong effect on current stock status. Although the status (biomass and fishing mortality rate) of major tuna and billfish stocks is well documented, the effect of these diverse factors on current stock status and the effect of management measures in rebuilding stocks have not been analysed at the global level. Here, we show that, particularly for tunas, stocks were more depleted if they had high commercial value, were long-lived species, had small pre-fishing biomass and were subject to intense fishing pressure for a long time. In addition, implementing and enforcing total allowable catches (TACs) had the strongest positive influence on rebuilding overfished tuna and billfish stocks. Other control rules such as minimum size regulations or seasonal closures were also important in reducing fishing pressure, but stocks under TAC implementations showed the fastest increase of biomass. Lessons learned from this study can be applied in managing large industrial fisheries around the world. In particular, tuna regional fisheries management organizations should consider the relative effectiveness of management measures observed in this study for rebuilding depleted large pelagic stocks. © 2016 John Wiley & Sons Ltd. Source

Hobday A.J.,CSIRO | Bell J.D.,Fisheries | Bell J.D.,University of Wollongong | Cook T.R.,University of Cape Town | And 2 more authors.
Deep-Sea Research Part II: Topical Studies in Oceanography | Year: 2015

Fishing in the open ocean often results in unwanted effects on target species, and interactions with non-target species (direct interactions) or influences on the prey or habitat of target and non-target species (indirect interactions). A number of conflicts and trade-offs exist in the harvesting of pelagic species, including (i) maximizing future food production given the depleted state of some stocks; (ii) minimizing bycatch of non-target species, (iii) setting ecosystem allocation rules for non-target top predators, such as seabirds, and (iv) maximizing value and livelihoods for local economies. Climate change can be expected to exacerbate some of these conflicts as the ranges of species and their habitats change over varying geographic, depth and temporal scales. Understanding the distribution of these impacts can be difficult due to the scarcity of observational data on species and ecosystems. Resolving all these conflicts is achievable with current approaches and technologies. Nevertheless, managing fishery production systems to provide fish for food security and conserving biodiversity will be particularly challenging. The complexity added by climate change can be managed with greater use of early warning systems and precautionary management. © 2014. Source

Bell J.D.,Fisheries | Ganachaud A.,Institute Of Recherche Pour Le Developpement | Ganachaud A.,CNRS Geophysical Research and Oceanographic Laboratory | Gehrke P.C.,SMEC Australia Pty Ltd. | And 13 more authors.
Nature Climate Change | Year: 2013

Pacific Island countries have an extraordinary dependence on fisheries and aquaculture. Maintaining the benefits from the sector is a difficult task, now made more complex by climate change. Here we report how changes to the atmosphere-ocean are likely to affect the food webs, habitats and stocks underpinning fisheries and aquaculture across the region. We found winners and losers - tuna are expected to be more abundant in the east and freshwater aquaculture and fisheries are likely to be more productive. Conversely, coral reef fisheries could decrease by 20% by 2050 and coastal aquaculture may be less efficient. We demonstrate how the economic and social implications can be addressed within the sector - tuna and freshwater aquaculture can help support growing populations as coral reefs, coastal fisheries and mariculture decline. © 2013 Macmillan Publishers Limited. All rights reserved. Source

Bell J.D.,Fisheries | Bell J.D.,Betty and Gordon Moore Center for Science and Oceans | Bell J.D.,University of Wollongong | Allain V.,Fisheries | And 18 more authors.
Marine Policy | Year: 2015

The large tuna resources of the Western and Central Pacific Ocean are delivering great economic benefits to Pacific Island countries and territories (PICTs) through sale of licences to distant water fishing nations and employment in fish processing. However, tuna needs to contribute to Pacific Island societies in another important way-by increasing local access to the fish required for good nutrition to help combat the world's highest levels of diabetes and obesity. Analyses reported here demonstrate that coastal fisheries in 16 of the 22 PICTs will not provide the fish recommended for good nutrition of growing Pacific Island populations, and that by 2020 tuna will need to supply 12% of the fish required by PICTs for food security, increasing to 25% by 2035. In relative terms, the percentages of the region's tuna catch that will be needed in 2020 and 2035 to fill the gap in domestic fish supply are small, i.e., 2.1% and 5.9% of the average present-day industrial catch, respectively. Interventions based on expanding the use of nearshore fish aggregating devices (FADs) to assist small-scale fishers catch tuna, distributing small tuna and bycatch offloaded by industrial fleets at regional ports, and improving access to canned tuna for inland populations, promise to increase access to fish for sustaining the health of the region's growing populations. The actions, research and policies required to implement these interventions effectively, and the investments needed to maintain the stocks underpinning the considerable socio-economic benefits that flow from tuna, are described. © 2014 Elsevier Ltd. Source

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