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1.
Two high value species, yellowtail kingfish (Seriola lalandi) and hāpuku (groper, Polyprion oxygeneios), have been identified as suitable new candidates for New Zealand aquaculture. This paper reviews the research by NIWA and collaborators conducted to test the biological, technological and economic feasibility of farming these two species. NIWA now has the capability to produce sufficient kingfish fingerlings per year to meet the needs of the early stages of an industry. Advances in hāpuku aquaculture have also been significant, from spawning in captivity through to the selection of juveniles for improved growth. Recently, the first spawning of captive hāpuku F1 broodstock and production of F2 eggs, larvae and juveniles was achieved. Although hāpuku larval survival remains variable, the ability to close the life cycle, and the availability of domesticated broodstock, provide a significant step forward and increase the chances of this species being commercially farmed.  相似文献   
2.
The solubilities and aqueous activity coefficients of polychlorinated biphenyls were measured in distilled and saline water (30? salinity). Solubilities in distilled water ranged from 3 · 10?4 g/l for dichlorobiphenyls to 6 · 10?6 g/l for heptachlorobiphenyls; values in artificial seawater were about five times lower than the corresponding values in distilled water. In both cases, the solubilities decreased regularly with increasing degree of chlorination. The corresponding activity coefficients are inversely proportional to the chlorine content and range from 4 · 107 to 4 · 109 in distilled water and from 3 · 108 to 1.5 · 1010 in saline water. Both the solubilities and activity coefficients agree well with those predicted from additivity considerations. The physical chemical aspects discussed in this paper can be applied in determining the solubility behavior of other stable organic molecules in the marine environment.  相似文献   
3.
西藏羊八井热田地热流体成因及演化的惰性气体制约   总被引:4,自引:5,他引:4  
赵平  Mack  KENNEDY 《岩石学报》2001,17(3):497-503
地热流体中惰性气体的相对丰度和同位素组成,不仅可以揭露热田的热源性质,而且还能够揭示深,浅层地热流体的内在联系和演化过程等。在西藏羊八井热田的地热气体中,已检测出大量的^4He组分,3He/^4He值是大气的0.087-0.259倍,表明深部地壳物质的局部熔融为热田提供能量,浅层地热流体的3He/4He 值自西北向东南呈降低趋势,与热储温度的变化相一致,反映出侧向运移时补充了更多的壳源氦,热田北区深层地热流体具有稍高的3He/4He值,是浅层地热流体的母源,气体中氪和氙的相对丰度具有大气降水成因的特征,结合现有的实际资料,建立了热田地热流体的概念模型。  相似文献   
4.
Biodiversity maps are an important component of ecosystem-based management and conservation. In the past, biodiversity maps were largely generated using patchy occurrence data from a range of data sources. Currently, substantial species occurrence data are readily available for large parts of the world and are accessible programmatically. Considering both the observed and expected changes in species distributions, and hence biodiversity, in response to present and future climate change, it is important to utilise readily available species occurrence databases to generate temporal and spatial biodiversity maps. In this study biodiversity maps were generated for three generic functional groups within the exclusive economic zone of South Africa: zooplankton, fishes and benthos. This was achieved by stacking individual species-distribution maps. Freely available occurrence data from the Ocean Biogeographic Information System (OBIS) were accessed for this purpose. Ensemble species-distribution modelling, employing five widely used statistical methods, was used to generate species-distribution maps for each functional group. The resulting spatial patterns of biodiversity for the three functional groups were largely in agreement with known patterns. The results of this study highlight the value of open-source occurrence and environmental data to generate biodiversity maps that can potentially be used in future spatial prioritisation or planning for management of marine areas and in environmental-change studies.  相似文献   
5.
The start of the Upper Würmian in the Alps was marked by massive fluvioglacial aggradation prior to the arrival of the Central Alpine glaciers. In 1984, the Subcommission on European Quaternary Stratigraphy defined the clay pit of Baumkirchen (in the foreland of the Inn Valley, Austria) as the stratotype for the Middle to Upper Würmian boundary in the Alps. Key for the selection of this site was its radiocarbon chronology, which still ranks among the most important datasets of this time interval in the Alps. In this study we re‐sampled all available original plant specimens and established an accelerator mass spectrometry chronology which supersedes the published 40‐year‐old chronology. The new data show a much smaller scatter and yielded slightly older conventional radiocarbon dates clustering at ca. 31 14C ka BP. When calibrated using INTCAL13 the new data suggest that the sampled interval of 653–681 m in the clay pit was deposited 34–36 cal ka BP. Using two new radiocarbon dates of bone fragments found in the fluvioglacial gravel above the banded clays allows us to constrain the timing of the marked change from lacustrine to fluvioglacial sedimentation to ca. 32–33 cal ka BP, which suggests a possible link to the Heinrich 3 event in the North Atlantic. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   
6.
The three countries of the Benguela Current Large Marine Ecosystem (BCLME), namely Angola, Namibia and South Africa, have committed to implementing ecosystem-based management (EBM) including an ecosystem approach to fisheries (EAF) in the region, to put in practice the principles of sustainable development in ocean-related matters. There is also recognition of the need for marine spatial planning (MSP) as a process for informing EBM with regard to the allocation and siting of ocean uses so that ecosystem health is ensured and trade-offs between ecosystem services are appropriately dealt with. Marine spatial planning is both an integrated and an area-based process, and this paper produces a spatial characterisation of the BCLME for achieving a common basis for MSP in the region, focusing on the oceanography, biology and fisheries. Recognising spatial variation in physical driving forces, primary and secondary production, trophic structures and species richness, four different subsystems are characterised: (1) north of the Angola–Benguela Front, (2) from the Angola–Benguela Front to Lüderitz, (3) from Lüderitz to Cape Agulhas, and (4) from Cape Agulhas to Port Alfred on the south-east coast of South Africa. Research and monitoring requirements of relevance for MSP and EBM in the region are identified, focusing on understanding variability and change, including with regard to the boundary areas identified for the system. To this end, 14 cross-shelf monitoring transects are proposed (including seven that are already being monitored) to estimate fluxes of biota, energy and materials within and between the subsystems. The usefulness of models for understanding ecosystem variability and changes is recognised and the need for fine-scale resolution of both sampling and modelling for adequate MSP as input to EBM for the often-conflicting interests of conserving biodiversity, and managing fisheries, recreation, offshore oil and gas exploration and exploitation, offshore mining and shipping routes, is emphasised.  相似文献   
7.
ABSTRACT

The grounding of the MV Rena has highlighted the lack of information concerning the effects of oil-related compounds on New Zealand marine life. Yellowtail kingfish (YTK), Seriola lalandi, embryos were exposed in static incubations to the water-accommodated fraction (WAF) of Rena heavy fuel oil as well as a similar preparation treated with the commercial dispersant Corexit 9500. Mortality in WAF treatments generally increased in association with total polycyclic aromatic hydrocarbon (tPAH) concentration over a 24-h period. Physical abnormalities were observed in some of the larvae exposed to WAF for 48 h. There was no survival in dispersed oil treatments after 24 h of exposure. These treatments had greater tPAH concentrations (2–53?µgL?1) than equivalent WAF dilutions (0.2–1.5?µgL?1?tPAH). Indications are that significant morbidity is induced in YTK at ecologically relevant tPAH concentrations. This highlights the need for further research into oil and dispersant toxicity in New Zealand marine species.  相似文献   
8.
The relative concentrations of non-polar organic compounds in seawater and suspended particulate matter can be explained by an equilibrium sorption mechanism. The value of the quasi-equilibrium constant, K, was calculated with reasonable accuracy for polychlorinated biphenyls from a relatively simple equation which relies on both measurable physical parameters and a number of molecular terms estimated from fundamental physical chemical considerations. This model represents an approach to defining the accumulation of stable organic molecules on marine particulate interfaces within a coherent theoretical framework. As such, it provides a guide for selecting appropriate ecosystem parameters which influence the distribution and accumulation potential of these chemicals in the marine environment.  相似文献   
9.
Journal of Seismology - On March 3, 2021, a strong shallow earthquake of magnitude Mw 6.3 struck Northern Thessaly, an area that lies in one of the most active fault zones of mainland Greece. The...  相似文献   
10.
The reliability of chlorinated hydrocarbon measurements in natural marine sediments is assessed statistically for the various sample treatments and quantitation techniques used by ten laboratories. For polychlorinated biphenyls, a standard deviation within ±25% of the mean can be expected. Methodology and spectral analysis are the major factors responsible for the variability. Extraction from dry sediment gives the greatest recovery, and measurement of chlorobiphenyl concentrations by homologs alleviates the effect of internal component changes.  相似文献   
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