南海南部陆缘盆地裂陷-漂移-前陆期构造演化及沉积响应:以礼乐盆地为例

通过礼乐盆地构造-地层-沉积分析，查明了其构造演化及沉积充填特征，揭示了其与南海扩张事件的成因联系，为南海边缘海演化研究提供了参考。研究结果表明:礼乐盆地新生代构造-沉积演化经历了3个差异显著的阶段，即古新世-早渐新世陆缘裂陷-滨浅海碎屑岩沉积阶段、晚渐新世-早中新世裂离漂移-浅海碳酸盐岩沉积阶段、中中新世以来周缘前陆挠曲沉降-区域差异沉积阶段。古新世-早渐新世，古南海向东南俯冲，华南古陆陆缘因水平引张力作用发生被动裂陷，形成礼乐盆地；此时以滨浅海环境为主，受碎屑物源供给控制，在盆地西北部发育一系列规模相对较大的辫状河三角洲，礼乐盆地东部、南部邻近古南海，仅在孤立隆起边缘发育规模较小的扇三角洲。晚渐新世-早中新世，古南海持续俯冲，新南海扩张，礼乐-巴拉望地块裂离华南古陆，向南漂移，盆地沉降缓慢，断层活动弱；此时以浅海-半深海环境为主，碎屑物源匮乏，盆地北部发育大型碳酸盐岩台地和生物礁，南部总体为半深海环境。中中新世以来，新南海扩张停止，礼乐-巴拉望地块向菲律宾岛弧俯冲碰撞，礼乐盆地进入周缘前陆期，以非对称挠曲沉降为特点，水深增大，断层活动增强；此时以半深海-浅海为主，盆地北部总体以碳酸盐岩台地和生物礁为特色，盆地南部局部发育深水重力流沉积。礼乐盆地构造-沉积演化与古南海俯冲-消亡、新南海扩张-关闭过程密切相关。      

Seismic sequence and depositional evolution of slope basins in mid-northern margin of the South China Sea

As one of the biggest marginal seas in the western Pacific margin, the South China Sea (SCS) experienced continental rifting and seafloor spreading during the Cenozoic. The northern continental margin of the SCS is classified as a passive continental margin. However, its depositional and structural evolution remains controversial, especially in the deep slope area. The lack of data hindered the correlation between continental shelf and oceanic basin, and prevented the establishment of sequence stratigraphic frame of the whole margin. The slope basins in the mid-northern margin of SCS developed in the Cenozoic; the sediments and basin infill recorded the geological history of the continental margin and the SCS spreading. Using multi-channel seismic dataset acquired in three survey cruises during 1987 to 2004, combined with the data of ODP Leg 184 core and industrial wells, we carried out the sequence stratigraphic division and correlation of the Cenozoic in the middle-northern margin of SCS with seismic profiles and sedimentary facies. We interpreted the seismic reflection properties including continuity, amplitude, frequency, reflection terminals, and 15 sequence boundaries of the Cenozoic in the study area, and correlated the well data in geological age. The depositional environment changed from river and lake, shallow bay to open-deep sea, in correspondence to tectonic events of syn-rifting, early drifting, and late drifting stages of basin evolution.     

ANOMALIES OF ASIAN SUMMER MONSOON RELATED TO SSTA IN THE SOUTH CHINA SEA AND THE TROPICAL PACIFIC

ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅＳｏｕｔｈＣｈｉｎａＳｅａ(ＳＣＳ)ｉｓａｐａｒｔｌｙ ｅｎｃｌｏｓｅｄｏｃｅａｎｂａｓｉｎｏｖｅｒｌａｉｄｂｙａｐｒｏｎｏｕｎｃｅｄｍｏｎｓｏｏｎｓｕｒｆａｃｅｗｉｎｄ .Ｐａｓｔｓｔｕｄｉｅｓ (Ｃｈｅｎｅｔａｌ.,1 991 ;ＤｉｎｇａｎｄＭｕｒａｋａｍｉ,1 994 ;Ｙａｎ ,1 997;ＬｉａｎｇＢｉｑｉ,1 991 ;ＬｉａｎｇＪｉａｎｙｉｎ ,1 991 )ｉｎｄｉｃａｔｅｔｈａｔａｈｕｇｅｗａｒｍｗａｔｅｒｐｏｏｌｊｏｉｎｔｌｙｃｏｎｔｒｉｂｕｔｅｄｂｙｔｈｅｗｅｓｔｅｒｎＰａｃｉｆｉｃ ,ｅａ…     

Water masses in the South China Sea and water exchange between the Pacific and the South China Sea

Water masses in the South China Sea (SCS) were identified and analyzed with the data collected in the summer and winter of 1998. The distributions of temperature and salinity near the Bashi Channel (the Luzon Strait) were analyzed by using the data obtained in July and December of 1997. Based on the results from the data collected in the winter of 1998, waters in the open sea areas of the SCS were divided into six water masses: the Surface Water Mass of the SCS (S), the Subsurface Water Mass of the SCS (U), the Subsurface-Intermediate Water Mass of the SCS (UI), the Intermediate Water Mass of the SCS (I), the Deep Water Mass of the SCS (D) and the Bottom Water Mass of the SCS(B). For the summer of 1998, the Kuroshio Surface Water Mass (KS) and the Kuroshio Subsurface Water Mass (KU) were also identified in the SCS. But no Kuroshio water was found to pass the 119.5°E meridian and enter the SCS in the time of winter observations. The Sulu Sea Water (SSW) intruded into the SCS through the Mindoro Channel between 50–75 m in the summer of 1998. However, the data obtained in the summer and winter of 1997 indicated that water from the Pacific had entered the SCS through the northern part of the Luzon Strait in these seasons, but water from the SCS had entered the Pacific through the southern part of the Strait. These phenomena might correlate with the 1998 El-Niño event.     

一种基于空间-拓扑结构相似性的复杂轨迹聚类算法

复杂的面状空间实体如海洋涡旋、环流和降雨过程在运动过程中会产生更复杂的轨迹,即具有分支结构的复杂轨迹。为了挖掘这类复杂轨迹的运动模式特征,本文从复杂轨迹的拓扑结构和空间特征出发,创新性地提出复杂轨迹的空间-拓扑结构相似性度量算法（Spatial-Topological Similarity Measurement, STSM）,该算法是基于图同构算法VF2改进的。首先STSM算法将复杂轨迹用带有节点和边的图结构表达,并将空间信息融入图结构的节点属性中,通过匹配复杂轨迹之间所有最大公共子结构,找到匹配结构中节点之间一一对应的关系,利用加权的欧式距离计算复杂轨迹匹配结构中点对之间的空间距离。然后,基于STSM相似性算法进行层次聚类分析,旨在发现复杂轨迹之间相似的拓扑结构在空间上的聚集模式。最后,利用1993-2016年长时间序列的中国南海冷涡复杂轨迹验证方法的有效性,并对比分析复杂轨迹拓扑结构相似性算法CSM。结果表明：单纯用拓扑结构相似性算法CSM进行聚类分析,不能充分挖掘空间的聚集模式,因为不同空间位置也存在拓扑结构相似的轨迹。而本文提出的STSM算法将南海冷涡复杂轨迹分为5类,第一类分布在南海北部、第二类分布在南海中部、其他三类交错在南海南部。这种聚集模式在一定程度上反映了冷涡的生成和演化过程在南海北部、中部、南部的差异性,同时也表明了冷涡移动在南海南部存在更为复杂的异质性。因此,本文提出的方法可以有效地从复杂轨迹数据中发现其演化过程的潜在聚集模式,为认识这类复杂动态现象的时空演化特征提供了一种新的方法。     

SEA SURFACE SALINITY AND BOTTOM WATER OXYGENATED CONDITIONS IN WESTERN EQUATORIAL PACIFIC MARGINAL SEAS DURING THE LAST GLACLAL AGE

ImODUcrIONThewesternPadricconsistSofaseriesofrnarginalbasins(twoofwhicharetheSrsandSuluSea)thatareseparatalfromeachotherbysdriofvaryingdepths.The25OOmdepthsiliseparatingtheSrsfromthewesternNorthPadricallowiPadricinteediatewatertoentertheSCS.Inconhast,theSuluSeaiscomPldelysurmundedbyasill,mostofwhichisshallowerthanlOomindepth.Thedeepestchanne1intotheSLduSeais42Omdeep(MindoroStrait)andcutSacrossthesillthatseparateStheSuluSeafromtheSrs.TheseenvironmntSresultalinspeda1hydrographicse…     

Submarine landslides on the north continental slope of the South China Sea

Recent and paleo-submarine landslides are widely distributed within strata in deep-water areas along continental slopes, uplifts, and carbonate platforms on the north continental margin of the South China Sea (SCS). In this paper, high-resolution 3D seismic data and multibeam data based on seismic sedimentology and geomorphology are employed to assist in identifying submarine landslides. In addition, deposition models are proposed that are based on specific geological structures and features, and which illustrate the local stress field over entire submarine landslides in deep-water areas of the SCS. The SCS is one of the largest fluvial sediment sinks in enclosed or semi-enclosed marginal seas worldwide. It therefore provides a set of preconditions for the formation of submarine landslides, including rapid sediment accumulation, formation of gas hydrates, and fluid overpressure. A new concept involving temporal and spatial analyses is tested to construct a relationship between submarine landslides and different time scale trigger mechanisms, and three mechanisms are discussed in the context of spatial scale and temporal frequency: evolution of slope gradient and overpressure, global environmental changes, and tectonic events. Submarine landslides that are triggered by tectonic events are the largest but occur less frequently, while submarine landslides triggered by the combination of slope gradient and over-pressure evolution are the smallest but most frequently occurring events. In summary, analysis shows that the formation of submarine landslides is a complex process involving the operation of different factors on various time scales.     

Monsoon-Ocean Coupled Modes in the South China Sea and Their Linkage with the Eastern Indian Ocean-Western Pacific Warm Pool

Monsoon-ocean coupled modes in the South China Sea （SCS） were investigated by a combined singular value decomposition （CSVD） analysis based on sea surface temperature （SST） and sea surface wind stress （SWS） fields from SODA （Simple Ocean Data Assimilation） data spanning the period of 1950-1999. The coupled fields achieved the maximum correlation when the SST lagged SWS by one month, indicating that the SCS coupled system mainly reflected the response of the SST to monsoon forcing. Three significant coupled modes were found in the SCS, accounting for more than 80% of the cumulative squared covariance fraction. The first three SST spatial patterns from CSVD were： （Ⅰ） the monopole pattern along the isobaths in the SCS central basin; （Ⅱ） the north-south dipole pattern; and （Ⅲ） the west-east seesaw pattern. The expansion coefficient of the SST leading mode showed interdecadal and interannual variability and correlation with the Indo-Pacific warm pool （IPWP）, suggesting that the SCS belongs to part of the IPWP at interannual and interdecadal time scales. The second mode had a lower correlation coefficient with the warm pool index because its main period was at intra-annual time scales instead of the interannual and interdecadal scales with the warm pools. The third mode had similar periods to those of the leading mode, but lagged the eastern Indian Ocean warm pool （EIWP） and western Pacific warm pool （WPWP） by five months and one year respectively, implying that the SCS response to the warm pool variation occurred from the western Pacific to the eastern Indian Ocean, which might have been related to the variation of Indonesian throughflow. All three modes in the SCS had more significant correlations with the EIWP, which means the SCS SST varied much more coherently with the EIWP than the WPWP, suggesting that the SCS belongs mostly to part of the EIWP. The expansion coefficients of the SCS SST modes all had negative correlations with the Nino3 index, which they lag by several months, indicating a remote response of SCS SST variability to the El Nifio events.     

DYNAMIC CHARACTERISTICS OF SEASONAL THERMOCLINE IN THE DEEP SEA REGION OF THE SOUTH CHINA SEA

ＩＮＴＲＯＤＵＣＴＩＯＮＸｕｅｔａｌ.(1993)ｓｔｕｄｉｅｄｔｈｅｂａｓｉｃｃｈａｒａｃｔｅｒｉｓｔｉｃｓｏｆｔｈｅｔｈｅｒｍｏｃｌｉｎｅｉｎｔｈｅｃｏｎｔｉｎｅｎｔａｌｓｈｅｌｆａｎｄｉｎｔｈｅｄｅｅｐｓｅａｒｅｇｉｏｎｏｆｔｈｅＳｏｕｔｈＣｈｉｎａＳｅａ(ＳＣＳ)ａｎｄｔｈｅｄｉｆｆｅｒｅｎｃｅｓｂｅｔｗｅｅｎｔｈｅｍｂｙａｎａｌｙｚｉｎｇ1907-1990ｈｉｓｔｏｒｉｃａｌｄａｔａｏｎｔｈｅＳＣＳ.Ｈｅｐｏｉｎｔｅｄｏｕｔｔｈａｔｔｈｅｔｈｅｒｍｏｃｌｉｎｅｉｎｔｈｅｄｅｅｐｓｅａｒｅｇｉｏｎｅｘｉｓ…     

2002-2012年青藏高原积雪物候变化及其对气候的响应

积雪是地表最活跃的自然要素之一,其动态变化对气候、环境以及人类生活都产生了重要影响。本文利用MODIS积雪产品和IMS雪冰产品,首先通过Terra、Aqua双星合成和临近日合成去除MODIS积雪产品中的部分云像元,再与IMS融合,获取了青藏高原2002-2012年逐日无云积雪覆盖产品,并逐像元计算每个水文年的积雪覆盖日数（SCD）、积雪开始期（SCS）和积雪结束期（SCE）,分析了不同生态分区积雪的时空变化特征,以及积雪开始期和结束期与温度、降水的关系。结果表明：青藏高原积雪分布存在明显的空间差异,南部喜马拉雅山脉和念青唐古拉山地区以及西部帕米尔高原和喀喇昆仑山脉为SCD的2个高值区,年均积雪日数在200 d以上。18.1%的区域SCS表现出明显的提前趋势,主要集中在青藏高原中东部;羌塘高原南部、念青唐古拉山西段以及川西地区有显著推迟趋势,占高原面积的8.5%。23.2%的区域SCE显著推迟,主要集中在果洛那曲高寒区、昆仑山区和念青唐古拉山地区;而仅有6.9%的区域表现出提前趋势,主要分布在高原西南部。总体上,不同生态单元内积雪开始与结束期受温度、降水的影响差异很大,表现出不同的空间格局与演变趋势。     

On the sources of the Taiwan Warm Current from the South China Sea

Historical hydrographic data across several sections in the South China Sea (SCS) and Taiwan Strait have been reconsidered. The year-around existence of the South China Sea Warm Current (SCSWC) along the shelf break off the Guangdong coast and the seemingly year-around southwestward current to the east of SCSWC are both evident in the data. The data also showed that the northward current in the Taiwan Strait seemed to be the extension of SCSWC. A barotropic numerical model is employed to explain some of the observed features. Reasonable simulation of the circulation in the northeast part of SCS has been found.     

Freshening of the intermediate water of the South China Sea between the 1960s and the 1980s

Variation in intermediate water salinity in the South China Sea (SCS) between the 1960s and 1980s was studied using historical hydrographic data. The results demonstrate that the water was significantly fresher in the 1980s than in the 1960s, indicating that vertical mixing at intermediate water depth was reduced in the 1980s. This was partially because of the change of the SCS meridional overturning circulation (MOC) connecting local intermediate water with deep water. Data assimilation showed a 0.5Sv (1 Sv=10 6m 3/s) reduction in the strength of the MOC, which is about one third of the mean SCS MOC. Because the SCS MOC is linked to the Pacific Ocean, such an interdecadal variation in the intermediate water SCS may reflect anthropogenic climate change in the world ocean.     

Statistical analyses of sea state conditions in South China Sea

The statistical characterization of sea conditions in the South China Sea(SCS) was investigated by analyzing a 30-year(1976–2005) numerically simulated daily wave height and wind speed data. The monthly variation of these parameters shows that wave height and wind speed have minimum values of 0.54 m and 4.15 ms~(-1), respectively in May and peak values of 2.04 m and 8.12 ms~(-1), respectively in December. Statistical analysis of the daily wave height and wind speed and the subsequent characterization of the annual, seasonal and monthly mean sea state based on these parameters were also done. Results showed that, in general, the slight sea state prevails in the SCS and has nearly the highest occurrence in all seasons and months. The moderate sea condition prevails in the winter months of December and January while the smooth(wavelets) sea state prevails in May. Furthermore, spatial variation of sea states showed that calm and smooth sea conditions have high occurrences(25%–80%) in the southern SCS. The slight sea condition shows the largest occurrence(25%–55%) over most parts of the SCS. High occurrences(8%–17%) of the rough and very rough seas distribute over some regions in the central SCS. Sea states from high to phenomenal conditions show rare occurrence(12%) in the northern SCS. The calm(glassy) sea condition shows no occurrence in the SCS.     

Influence of the Convection over the South China Sea on the Summer Precipitation of Shandong Province

1　Introduction　ShandongProvince ,whichislocatedintheeastofChina ,consistspartlyofpeninsulaandpartlyofinlandwithatotalareaofabout 1 5 0 0 0 0km2 .Lyingfrom34°2 0′Nto 38°2 0′Nandfrom 1 1 4°4 0′Eto 1 2 2°4 0′E ,alltheareabelongstothemoderateregionandtothetypicalAsianmonsoonclimate .SoShandong’ssum merprecipitationaccountsforover 6 0 %oftheannualrainfall,andaccordinglyflood droughtdisastersmain lyoccurinsummer.Moreover,becauseitisgeographi callylocatedinthetransitionalareabetweenthe…     

豫陕交界地区金银多金属矿床时间分布规律研究

豫西金银矿床的成矿时代问题目前尚有许多不同认识。本文通过对砂金分布、岩矿脉体穿插关系以及矿石同位素测年结果等实际资料的综合研究分析，证明本区金银矿床的主成矿期应为燕山晚期；同时归纳出区内各类金属矿产在时间演化上具有长期性、多期性、阶段性、序列性、继承性诸项规律。     

Vorticity budget study on the seasonal upper circulation in the northern South China Sea from altimetry data and a numerical model

Based on the EOF analyses of Absolute Dynamic Topography satellite data,it is found that,in summer,the northern South China Sea(SCS) is dominated by an anticyclonic gyre whilst by a cyclonic one in winter.A connected single-layer and two-layer model is employed here to investigate the dynamic mechanism of the circulation in the northern SCS.Numerical experiments show that the nonlinear term,the pressure torque and the planetary vorticity advection play important roles in the circulation of the northern SCS,whilst the contribution by seasonal wind stress curl is local and limited.Only a small part of the Kuroshio water intrudes into the SCS,it then induces a positive vorticity band extending southwestward from the west of the Luzon Strait(LS) and a negative vorticity band along the 200 m isobath of the northern basin.The positive vorticity field induced by the local summer wind stress curl is weaker than that induced in winter in the northern SCS.Besides the Kuroshio intrusion and monsoon,the water transports via the Sunda Shelf and the Sibutu Passage are also important to the circulation in the northern SCS,and the induced vorticity field in summer is almost contrary to that in winter.The strength variations of these three key factors(Kuroshio,monsoon and the water transports via the Sunda Shelf and the Sibutu Passage) determine the seasonal variations of the vorticity and eddy fields in the northern SCS.As for the water exchange via the LS,the Kuroshio intrusion brings about a net inflow into the SCS,and the monsoon has a less effect,whilst the water transports via the Sunda Shelf and the Sibutu Passage are the most important influencing factors,thus,the water exchange of the SCS with the Pacific via the LS changes dramatically from an outflow of the SCS in summer to an inflow into the SCS in winter.     

Strengthening effect of super typhoon Rammasun(2014) on upwelling and cold eddies in the South China Sea

Typhoon is one of the frequent natural disasters in coastal regions of China.As shown in many studies,the impact of typhoons on the South China Sea(SCS) should not be overlooked.Super typhoon Rammasun(2014) was studied that formed in the northwestern Pacific,passed through the SCS,then landed in the Leizhou Peninsula.Remote sensing data and model products were used to analyze the spatiotemporal variations of the cold eddies,upwelling,sea surface temperature,mixed layer depth,rainfall,sea surface salinity,suspended sediment concentration,and surface-level anomaly.Results confirm the constant presence of upwelling and cold eddies in the southeast of Hainan(north of the Zhongsha Islands) and the southeast of Vietnam in July.In addition,we found the strengthening effect of super typhoon Rammasun on the upwelling and cold eddies in the SCS.The major reasons for the continuous decrease in sea surface temperature and the slow regaining of seawater temperature were the enhanced upwelling and vertical mixing caused by the typhoon.The increasing of the surface runoff in the Indochina Peninsula was mainly affected by the typhoon,with some contribution for the southeast of Vietnam's cold eddy and upwelling.     

SST INTRASEASONAL OSCILLATION AND ATMOSPHERIC FORCING SYSTEM OF THE SOUTH CHINA SEA

ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅＳｏｕｔｈＣｈｉｎａＳｅａ (ＳＣＳ)ｉｓａｓｅｍｉ ｅｎｃｌｏｓｅｄｏｃｅａｎｂａｓｉｎｌｏｃａｔｅｄａｔａｓｐｅｃｉａｌｇｅｏｇｒａｐｈｉｃｐｏ ｓｉｔｉｏｎ ,ｏｎｅｏｆｔｈｅｗｏｒｌｄ’ｓｐｒｏｎｏｕｎｃｅｄｍｏｎｓｏｏｎｒｅｇｉｏｎｓ,ｗｉｔｈｎｏｒｔｈｅａｓｔｗｉｎｄｓｐｒｅｖａｉｌｉｎｇｉｎｗｉｎｔｅｒａｎｄｓｏｕｔｈｗｅｓｔｗｉｎｄｓｉｎｓｕｍｍｅｒ,ａｎｄｉｓａｃｒｕｃｉａｌｒｅｇｉｏｎｏｆｉｎｔｅｎｓｉｖｅａｉｒ ｓｅａｉｎｔｅｒａｃｔｉｏｎｏｆｇｒｅａｔ…     

Comparison of remote sensing data with in-situ wind observation during the development of the South China Sea monsoon

Wind measurements derived from QuikSCAT data were compared with those measured by anemometer on Yongxing Island in the South China Sea (SCS) for the period from April 2008 to November 2009. The comparison confirms that QuikSCAT estimates of wind speed and direction are generally accurate, except for the extremes of high wind speeds (>13.8m/s) and very low wind speeds (<1.5m/s) where direction is poorly predicted. In-situ observations show that the summer monsoon in the northern SCS starts between May 6 and June 1. From March 13, 2010 to August 31, 2010, comparisons of sea surface temperature (SST) and rainfall from AMSR-E with data from a buoy located at Xisha Islands, as well as wind measurements derived from ASCAT and observations from an automatic weather station show that QuikSCAT, ASCAT and AMSR-E data are good enough for research. It is feasible to optimize the usage of remote-sensing data if validated with in-situ measurements. Remarkable changes were observed in wind, barometric pressure, humidity, outgoing longwave radiation (OLR), air temperature, rainfall and SST during the monsoon onset. The eastward shift of western Pacific subtropical high and the southward movement of continental cold front preceded the monsoon onset in SCS. The starting dates of SCS summer monsoon indicated that the southwest monsoon starts in the Indochinese Peninsula and forms an eastward zonal belt, and then the belt bifurcates in the SCS, with one part moving northeastward into the tropical western North Pacific, and another southward into western Kalimantan. This largely determined the pattern of the SCS summer monsoon. Wavelet analysis of zonal wind and OLR at Xisha showed that intra-seasonal variability played an important role in the summer. This work improves the accuracy of the amplitude of intra-seasonal and synoptic variation obtained from remote-sensed data.     

Natural mortality estimation and rational exploitation of purpleback flying squid Sthenoteuthis oualaniensis in the southern South China Sea

Based on the biological data of purpleback flying squid(Sthenoteuthis oualaniensis)collected by light falling-net in the southern South China Sea(SCS) during September to October 2012 and March to April 2013,growth and mortality of 'Medium' and 'Dwarf' forms of squid are derived using the Powell-Wetherall,ELEFAN methods and length-converted catch curves(FiSAT package).Given a lack of commercial exploitation,we assume total mortality to be due entirely to natural mortality.We estimate these squid have fast growth,with growth coefficients(k) ranging from 1.42 to 2.39,and high natural mortality(M),with estimates ranging from 1.61 to 2.92.To sustainably exploit these squid stocks,yield per recruitment based on growth and natural mortality was determined using the Beverton-Holt dynamic pool model.We demonstrate squid stocks could sustain high fishing mortality and low ages at first capture,with an optimal fishing mortality 3.0,with the optimal age at first capture increased to 0.4-0.6 years when fishing mortality approached optimal levels.On the basis of our analyses and estimates of stock biomass,we believe considerable potential exists to expand the squid fishery into the open SCS,relieving fishing pressure on coastal waters.