Full retention in tuna fisheries: Benefits,costs and unintended consequences

Several tuna regional fisheries management organizations (t-RFMOs) have adopted retention requirements for skipjack, bigeye and yellowfin tunas caught by purse seine vessels to reduce discards, create disincentives to catch small fish, and incentivize the development and adoption of more selective technologies. Although retention policies in the t-RFMOs have been limited to target tunas in purse seine fisheries, some have advocated for an expansion of those policies, and t-RFMOs could consider expanding retention policies to a greater number of species and/or to other gear types. This paper discusses the benefits and costs of broader retention policies for purse seine and longline tuna fisheries in the western and central Pacific Ocean (WCPO). Using bycatch data from observers and logbooks from the U.S. purse seine and longline fleets operating in the WCPO, this paper documents the types and magnitude of fish discarded. For the purse seine fishery, this information was used to estimate direct impacts of having to off-load at the initial point of landing in key Pacific Island ports. For the longline fishery, estimates of direct impacts were limited to Honolulu and Pago Pago, American Samoa, the two primary ports where U.S. catch is landed. Expanding retention policies beyond the target tunas and to other gear types would further reduce discarding and possibly provide stronger incentives to develop and use more selective techniques. Beyond impacts to the ecosystem and fisher behavior, adopting broader retention policies may have other implications, and this paper explores those implications on vessels, processors, and communities. In general, as is the case with most direct interventions on fishing operations, there will be both benefits and costs, and the magnitude of those impacts will depend on the scope and extent of any expanded retention policy.     

Resee矿山遥感监测系统变化向导模块在矿山变化信息提取中的应用

依靠自主研发的Resee矿山遥感自动监测系统中的变化向导模块可对矿区进行方法评价及变化图斑提取,辅助相关部门监视工作区存在的部分违规采矿行为,很好地实现对矿区采矿行为及影像的动态监测,对矿山环境的变化进行有效的监督管理,大大提高了矿山监测的效率和准确性.     

黔西地区基于抗旱找水的打井技术方法分析

黔西地区抗旱找水区域性影响因素明显,需对区域储水构建进行分析研究,为勘察及取水设计奠定基础。在找水过程中,取用数据收集和现场分析的方法,运用物探和遥感地质技术,有效的进行赋水和井深选择。在区域研究从相关的文献资料中寻找理论依据;对技术勘察,取水设计、资料收集、现场分析等几个阶段进行探讨。经过研究得出：在黔西地区找水过程中可以有效的实现富水区段选择,解决当地居民生活用水。     

西澳州Cattle Creek地区铜镍硫化物矿床成矿潜力探讨

西澳州Catlle Creek地区位于金伯利地块西缘霍尔斯克里克(Halls Creek)活动带上,附近发育有深大断裂。研究区内发现多处基性-超基性小岩体及岩脉且存在两处矿化点(带),存在两处1∶5万土壤地球化学甲类综合异常区,二者均主要由Cu、Ni、Au、Mo、Co等元素组成,多个浓集中心,异常套合较好,Cu、Ni的极大值均超过或接近边界品位,甚至工业品位,二者与矿化等信息套合良好。岩体中岩石样品主量元素特征显示其具有辉长岩-苏长岩的成矿专属性特征;在AFM图解上,岩石样品显示原始岩浆为高MgO拉斑玄武岩系列。微量元素原始地幔标准化蛛网图表明岩体岩浆演化过程中发生过明显的陆壳物质同化混染作用。稀土元素配分图反映出成岩过程中有相似的分异演化过程,并表明岩浆在演化过程中存在明显橄榄石分离结晶作用。研究区与萨凡纳矿床具有很高的可对比性,同时符合古大陆内小岩体成矿系统理论。表明研究区具较高的成矿潜力。     

河南栾川火神庙钼矿床辉钼矿Re-Os同位素年龄及其地质意义

火神庙矽卡岩型钼矿床是东秦岭钼矿带栾川矿集区近些年查明的一个中型钼矿床,钼矿体主要赋存于火神庙复式岩体与新元古界蓟县系三川组大理岩接触带的矽卡岩中。为厘定火神庙钼矿床的成矿时代、成矿物质来源及与南泥湖—三道庄、上房沟钼矿床的关系,采用ICP-MS辉钼矿Re-Os同位素定年法对6件辉钼矿样品进行成矿年龄测定,获得的模式年龄为146.1Ma±2.0Ma~148.1Ma±2.1Ma,年龄加权平均值为147.01Ma±0.95Ma,等时线年龄为145.7Ma±3.9Ma,表明火神庙钼矿床形成于晚侏罗世。辉钼矿样品的Re含量为39×10-6~65.4×10-6,显示成矿物质来源于壳幔混源。火神庙钼矿床与南泥湖—三道庄、上房沟钼矿床均为栾川矿集区晚侏罗世第二次岩浆活动的产物,它的发现为在栾川矿集区西部寻找矿产资源提供了依据。     

江汉平原西部浅层孔隙水水文地球化学特征

为了揭示地下水由江汉平原周缘向中心径流过程中的水质演化和复杂的水文地球化学作用,以江汉平原西部地区为例,通过数理统计、水化学、同位素地球化学、离子比值关系等方法,开展了江汉平原西部边缘地带浅层孔隙地下水的水文地球化学特征研究。结果表明: 平原区孔隙水以HCO₃-Ca·Mg型为主,丘岗区(丘陵和岗地)主要是HCO₃-Ca·Mg型,少量为HCO₃·SO₄-Ca·Mg型,还出现了HCO₃·NO₃-Ca·Mg型水,总溶解固体(total dissolved solids,TDS)升高主要是由于碳酸盐岩的溶解; 浅层孔隙水均来源于大气降水,蒸发作用对该地区孔隙水的影响较小; 方解石、白云石和石膏的溶解主导研究区的水文地球化学过程,也是孔隙水中Ca²⁺、Mg²⁺的主要来源,Na⁺和K⁺的主要来源是阳离子交换吸附。     

New insight on the genus Nolaniceras Casey, 1961 (Ammonoidea,Cretaceous) and its consequences on the biostratigraphy of the Aptian Stage

Nolaniceras nolani ( Seunes, 1887) has been widely quoted in the Upper Aptian literature over the years. Re-examination of the holotype of the species shows that it has always been misidentified and that this taxon is represented by a single specimen, the holotype, of uncertain age. As a consequence, its use as an index species for the Upper Aptian should be reconsidered and abandoned.     

A New Lizard (Lepidosauria: Squamata) from the Upper Cretaceous of Henan, China

Funiusaurus luanchuanensis gen. et sp. nov. was described on the basis of an incomplete skull from the Upper Cretaceous Qiupa Formation of the Tantou Basin in Luanehuan County, Henan Province. It is the second representative of lizards known from Luanchuan and adds a new member to the Luanchuan Fauna. F. luanchuanensis is a small-sized lizard and systematically assigned to the Polyglyphanodontidae of the Teiioidea because of the presence of a caniniform tooth and an elongate posterior process of the postorbital. It is distinctive in that the heterodont dentition bears 19 teeth in both the upper and lower jaws, the 3^rd maxillary tooth is large and caniniform, the post-caniniform teeth in maxilla and those posterior to the 3^rd dentary tooth are chisel-like in lateral view, the prefrontal possesses a fossa on its lateral surface, the postorbital with an extremely elongate posterior process and the well-developed retroarticular process has a deep fossa on its dorsal surface. In phylogeny, our analysis suggests a close relationship of Funiusaurus to the large-sized Tianyusaurus from the same basin within the Tuberocephalosaurinae. The discovery of Funiusaurus is significant in confirming the status of the Tuberocephalosaurinae, which includes a group of the Asian members of the Polyglyphanodontidae only.     

河南省庙咀钒矿地质特征及成矿浅析

庙咀钒矿是近年查明的一个中型钒矿床。钒矿床地处荆紫关—师岗复向斜南翼,矿体赋存于下寒武统水沟口组底部硅质岩和泥岩中,严格受控于地层及岩性。矿石类型主要为黏土岩型及条带状硅质岩型两种,钒主要以离子吸附和类质同象赋存于黏土矿物中。矿床成因为滨海-浅海沉积型层控矿床。     

河南省侵入岩构造单元的划分及其特征

河南省岩浆活动显示多期活动的特征,侵入岩较发育,占全省基岩出露面积的23.5%以上,岩石类型齐全,与其有成生联系的矿产资源丰富。文章参考潜力评价全国构造侵入岩带的总体划分方案,结合河南省岩浆岩分布特征、岩石类型、岩石组合及岩浆岩的演化规律,划分出2个构造侵入岩省、5个构造侵入岩带、12个构造侵入岩亚带、进一步划分出22个构造侵入岩段,并对其基本特征及与成矿关系进行总结。