GPS-RTK技术在汕头海洋测绘中的应用

<正>最近几年,GPS-RTK发展迅速,在工程测量、海洋测绘和不动产测绘等方面应用广泛。从某种意义上所说,GPS-RTK技术是测绘领域的技术革命。汕头市海域辽阔,全市领海基线以内亦称内水的海域面积约2796km2,全市大陆海岸线长227.49km,有大小海岛84个,尤其适合使用GPS-RTK技术进行海洋测绘。     

海域使用后评价体系的基本概念

本刊讯：最近中国海洋战略发展研究中心王曙光教授等撰文,论述我国海域使用后评价体系的研究,文中概述了海域使用后评价体系概念。所谓海域使用后评价是指海洋工程项目建成并正式投入生产运营一段时间以后,通过调查研究该海洋工程项目实际发生的社会影响、经济效益影响和环境影响,并同该海洋工程项目的海域使用论证中的预测评价成果进行对比,     

卫星遥感北太平洋渔场叶绿素a浓度

海洋叶绿素a(Chla.)含量是了解世界海洋中地球生物化学循环的基础和估算海洋生产力的基本指标,是判断水域的肥瘠程度和评价水域渔业潜在生产力的基本依据。富集浮游植物的海域是海洋食植动物的大密度存在和水产资源丰富存在的基础,许多鱼类如金枪鱼等中上层鱼群集在锋面两侧或涡旋,这些特征与营养盐供给或混合层深度变化相关。北太平洋渔场已成为我国远洋渔业的重要组成部分,卫星遥感技术可以实现大面积同步的观测和一年四季连续的观测,是测定北太平洋渔场海洋叶绿素a的最有效方法。1 材料和方法1.1 数据来源卫星资料采用美国海洋水色卫星的宽视场海洋水色扫描仪(SeaWiFS)资料,全球海上测量资料利用国际海洋水色协调工作组(IOCCG)在世界大洋范围测量的1175个站位光谱数据和对应的叶绿素a浓度,南海测量数据由国家海洋技术中心在南海测量的48个站位光谱数据和叶绿     

面朝大海 走进海博 《海洋与渔业》杂志社举办青少年海洋意识教育活动

<正>为了让青少年了解中国海洋产业,增强海洋意识,10月15日,《海洋与渔业》杂志社与广东省海洋工程职业技术学校携手,组织开展以"面朝大海走进海博"为主题的青少年海洋产业观展活动。活动当日,在学校老师和《海洋与渔业》杂志社工作人员的组织下,来自广东省海洋工程职业技术学校养殖、海事工程、制冷与机电工程、环保与     

海洋测绘技术的现状及最新进展

<正>海洋测绘在国防建设以及经济建设当中都有着重要意义。随着信息技术的发展,海洋测绘技术也随之取得跨越式发展,在海洋事业当中发挥着更加重要的作用。1.海洋测量的现状1.1物理海洋测量物理海洋测量是对海洋底部的物理场性质进行测量,通过应用物理学测量方法来调查海洋地质构造以及矿产分布,常用的测量方法有重力测量、地震测量、磁力测量以及声学测量等。海洋重力测量是测量海上重力加速度,近年     

河北省海洋渔业发展现状调研报告

<正>21世纪是海洋世纪,开发海洋和发展海洋经济已成为世界各沿海国家的战略重点,特别是随着世界范围内陆地人口与资源矛盾的日益突出,越来越多的人将目光投向这片蓝色国土。美国自90年代以来,为保持其世界领先与渔霸主地位,加强了对海洋工作的组织与调整,加大了海洋科技投入,在海洋工程、海洋生物技术、海水综合利用技术等方面发展迅速,并以其资本和技术优势开辟中国海洋市场,既增强了他本国的海洋经济实力,又维护     

浅谈加快发展广东海洋新兴产业

随着海洋综合开发的广度和深度不断拓展,以海洋生物医药、海洋工程装备制造、海水综合利用和海洋可再生能源为主的海洋新兴产业已成为抢占新一轮海洋经济制高点的朝阳产业。在国务院批复的矿东海洋经济综合试验区发展规划》（以下简称《发展规划》）中明确提出广东要“培育壮大海洋新兴产业”,将“广东建设成为提升我国海洋经济国际竞争力的核心...     

珠海外伶仃岛海域海洋牧场选址探讨

海洋牧场选址是海洋牧场建设前需首要考虑的重要环节,适宜的选址是确保海洋牧场建设成功的前提。文章从海岸线稳定性、海洋功能区划、海洋生态红线、养殖水域滩涂规划、海洋工程和设施等5个方面选取了34个指标作为海洋牧场适宜性评价的因素,建立海洋牧场选址指标体系。在此基础上,根据珠海外伶仃岛海域实际情况,选取岛屿海岸线长度和面积变化强度、海洋功能区划、海洋生态红线、养殖水域滩涂规划、港口、锚地、通航密集区、海底管线等8个指标,采用地理信息系统空间分析方法,对珠海外伶仃岛海域海洋牧场选址进行适宜性评价。结果表明,研究区域内无最适宜和较适宜进行海洋牧场建设的区域,一般适宜和不适宜的区域所占面积分别为33.09和45.59 km²,其中适宜海洋牧场建设区域与珠海市目前已建人工鱼礁和规划海洋牧场区域范围相近。     

青岛国际海洋技术与工程设备展览会(Oi China 2018)

正第六届Oi China国际海洋技术与工程设备展览会将于2018年10月23-25日在全新的展馆——青岛世界博览城拉开帷幕。凭借姊妹展"英国(伦敦)国际海洋技术与工程设备展览会"40余年来积累的丰富行业经验及五届Oi China展会的成功举办,2018青岛国际海洋技术与工程设备展览会预计将吸引来自20余个国家和地区的逾200家供应商,通过展示国内外技术、装备,以推动中国、亚洲乃至全球在海洋资源开发利用、海洋生态环境保护、海洋石油天然气勘探、海洋工程及海洋监测等领域的学术研究、信息交流和国际合作。     

云洲智能:无人系统领航深蓝探索

正探索深蓝,任重而道远,在复杂、多变、高危的未知领域中,高新技术占据了一个重要的位置。随着技术升级,海洋工程装备的大家庭加入了一位新成员——无人船,而珠海云洲智能科技有限公司(以下简称"云洲")正是无人船行业的佼佼者。云洲于2010年成立,专注于水面无人艇技术的研发和应用,至今已开发出环境测量系列无人船、海洋调查系列无人艇、安防搜救系列无人艇、军用系列无人艇以及无人货运等五大系列产品。     

海水网箱网衣防污技术的研究进展

海水网箱养殖中,网衣污损附着物会影响网箱设施安全及其养殖鱼类的健康生长,因此,网衣防污是网箱养殖业备受关注的问题.本文在简述海水网箱网衣分类与特点的基础上,重点介绍了人工清除法、防污涂料法、机械清除法、金属合金网衣防污法、箱体转动防污法、生物防污法、网衣本征防污法等网衣防污技术最新研究进展;结合本课题组在网衣防污方面的...     

Variations in reproductive potential between nearshore and offshore spawning contingents of hogfish in the eastern Gulf of Mexico

Hogfish, Lachnolaimus maximus (Walbaum), have multiple traits that confound measuring reproductive potential: they are protogynous, relatively long‐lived harem‐forming fish that spawn daily for months. Additionally, recent evidence demonstrates that size, age and timing of sex change vary on a spatial scale within the study area (West Florida shelf, USA). This study investigates the effect of this spatial variation on hogfish reproductive potential by evaluating spawning seasonality, spawning frequency and batch fecundity using an indeterminate egg production model. Offshore females were larger than nearshore females, and batch fecundity was related in a log‐linear manner to female size. Gonad histology demonstrated a more protracted reproductive period for females offshore (8 months) than nearshore (4 months). Spatial variations in size coincide with ontogeny because hogfish move offshore with growth; however, even after accounting for fish size, offshore females spawned more. In areas where male removal rates are elevated, spawning harems are disrupted; thus, greater fishing effort nearshore may further reduce the reproductive potential of these females. These nearshore and offshore spawning components of the population are not genetically distinct, but instead represent two contingent spawning strategies that likely enhance total population stability and resilience of this stock in the eastern Gulf of Mexico.     

利用数码技术测定鲆鲽类体表面积的方法

提出一种快速、准确测定鲆鲽类体表面积的新方法,利用数码相机拍照获取带有标准坐标纸背景的鲆鲽类鱼体数码图像,采用图像处理软件Photosllop CS2和Adobe Acrobat Professional分别获得单位背景面积和鱼体图像的像素数,通过两者的比例计算出体表面积.30尾大菱鲆(Scophthalmus maximus)体表面积的实测表明,与传统计数方格面积法的测量结果相比,Photoshop法相对误差为-4.40%～3.08%,Acrobat法相对误差为-1.83%～1.30%.统计分析显示,2种图像处理软件所测数据与传统方法测量值间差异都不显著,测量1尾大菱鲆体表面积,传统方法约耗时15 min,Plaotoshop和Acrobat法分别只需3 min和1.5 min.新方法可以迅速和准确地测定鲆鲽类体表面积,便于鲆鲽类养殖生产中对养殖密度进行有效管理.     

Examination of net volume reduction of gravity-type open-net fish cages under sea currents

Owing to heavy criticisms of nearshore fish farming for causing environmental pollution and encroaching on sea space used for shipping, boating, recreational sea activities and marine eco-tourism, offshore fish farming has now being seriously considered. Moreover an offshore site provides more pristine water and greater space for increased fish production. However, offshore fish farming poses challenges such as a more energetic sea environment. A higher sea current can lead to large deformation of fish net and hence a net volume reduction which compromises fish welfare. With the view to identifying the effects of various important parameters on net volume reduction of a gravity-type open-net fish cage, this paper adopts a mass-spring model for the dynamic analysis of current-induced net deformations of cylindrical fish nets with discrete weights hanging at the bottom edge of the nets. In this model, the net mesh comprises knot nodes and bar nodes connected by tension-only massless springs. The spring stiffness is determined from the net bar diameters and material properties. The current-induced loads are applied to each node and calculated based on Morrison’s equation. The governing equation system for nodal motions can be established according to Newton’s second law, and solved by using the Runge-Kutta method for the real-time net deformations. The effects of net string reinforcements, weight distributions and net shapes on the net volume reduction are studied with the view to shed insights into how one may improve fish cage designs to effectively mitigate net deformation under high sea current speeds in offshore fish farming sites.     

深水网箱多波束水声鱼群状态监测仪的改进设计

针对离岸深水网箱养殖的鱼群安全问题,采用多波束水声技术监测鱼群状态的方法.结合信号处理技术、通用分组无线业务(GPRS)无线传输技术及串口通信技术,开发了一套多波束水声鱼群状态监测仪.监测仪完成1次网箱扫描只需5s;实现了监测数据的即采即发功能,提高了系统的实时性;改进了电路结构,降低了系统复杂度,减小了系统体积,降低...     

基于耳石δ13C和δ18O的黄、渤海秋季小黄鱼补充群体的种群划分

关于小黄鱼的种群划分问题,从20世纪50年代至今一直存在争议。以往研究海洋鱼类种群划分的方法主要有标记重捕法、渔获量分析法、寄生虫标记法、形态表型量度特征法、分子生物学法和钙质结构元素指纹法等,而这些方法在细节的表述方面有各自的局限性。本研究采用稳定同位素质谱分析技术,分析了黄、渤海渔业资源调查中92尾小黄鱼(Larimichthys polyactis)的左矢耳石样品中δ^13C和δ^18O的值,并对每尾小黄鱼耳石δ^13C和δ^18O的值进行聚类分析。结果显示,我国黄、渤海秋季小黄鱼早期补充群体可划分为4个种群,即渤海黄海北部种群、黄海中部种群、黄海南部离岸种群和黄海南部沿岸种群。其中,黄海南部离岸种群和其他3个种群没有站位交叉现象。对聚类分析的结果进行判别分析,得出渤海黄海北部种群的判别成功率为75.9%,黄海中部种群的判别成功率为80.0%,黄海南部离岸种群判别成功率为81.0%,黄海南部沿岸种群判别成功率为95.5%,总体判别成功率为82.6%。首次将黄海南部种群细分为了黄海南部离岸种群和黄海南部沿岸种群,且2种群之间很少有站位的交叉现象。     

基于北斗船位数据的江苏渔船航次分析

北斗船舶监控系统(VMS)包含渔船的位置、航速等数据,能用于挖掘渔船作业的动态信息。利用VMS数据对江苏渔船的航次和平均离岸距离进行提取,分析不同船长、类型、作业期、地区等条件下航次和平均离岸距离的特点。结果显示:1)江苏不同作业类型渔船航次差别明显,刺网航次数量最多,占总航次数的84.6%,围网和张网作业渔船的平均离岸距离和平均作业时间大于其他作业类型,围网作业渔船最远可达174.02 km;2)江苏渔船大部分为中小型渔船,作业的平均离岸距离比较小,基本在80 km以内,平均离岸距离随着吨位和功率的增大而线性增大;3)全年的航次数量变化分布整体中间低两边高,4月、9~11月航次数较多,2月、5~7月航次数较少;4)江苏不同区县渔业差距较大,航次数最多的为南通启东市、如东县和盐城射阳县,渔船作业平均离岸距离最远的为苏州太仓市,最远可达332.38 km。研究结果可为江苏省渔业管理提供参考依据。     

MUSSEL CULTIVATION AS A CO-USE IN OFFSHORE WIND FARMS: POTENTIAL AND ECONOMIC FEASIBILITY

More than 50% of the annual worldwide harvest of mussels is produced in Europe. The mussel cultivation in Germany is based on an extensive on-bottom culture and depends entirely on natural resources for food, spat and space. Due to stakeholder conflicts and a lack of spat availability, mussel farmers tend to move offshore where space is not limited and adequate settlement guaranteed. Newcomers – the offshore wind farmers – are covering large areas in the German Bight which in contrast give the opportunity to use these areas in a multifunctional way by accepting mussel cultivation within the wind farms. This study compiles the basic data for offshore mussel cultivation in close vicinity to a designated offshore wind farm in the open sea of the German Bight and employs different case-scenario calculations to illustrate the impact of changing parameter values on overall profitability or non-profitability of this activity. Primary focus is placed on the production of consumer mussels but seed mussel cultivation is also taken into consideration. We show that production of consumer mussels with longline technology is sufficiently profitable even under the assumption of substantial cost increases. This is especially true, if existing capacities could be used. The cultivation of seed mussels depends on the possibility of using existing equipment. A substantial increase of seed mussel prices to at least 0.6 €, given the main cost categories remaining constant, turns this alternative into substantial profitability. This study concludes with providing some recommendations on how favorable terms or actions could further improve profitability of offshore mussel cultivation. Altogether, our results are intended to shed some light on business management topics that future offshore mariculture operators such as traditional mussel farmers should follow in order to be efficient.     

Effects of Reduced Fishing for Feeding Salmon (Salmo salar L.) in the Baltic on Home Water Fisheries according to Simulations with the Carlin-Larsson Population Model

The Carlin-Larsson population model of Baltic salmon was used to simulate reduced effort in an offshore fishery for feeding salmon and its effect on home water fisheries. Some simplifying assumptions had to be made; no changes in seasonal mean weight or exploitation rate in the home water fisheries were assumed. With a simulated termination of the offshore fishery, seasonal mean weights from the time before the excessive offshore fishery started were also applied to give a maximum effect on the catches. The total non-catch fishing mortality in the offshore fishery was estimated at 5% per season (total M = 10% per season). A total ban on the offshore fishery would mean a sixfold increase in catch-value for home water fisheries and a total value twice that in the present situation with the present seasonal mean weights. With the higher mean weights the simulated catch would be 87% and its value 182% higher than at present.     

On the relationship between the Oyashio front and saury fishing grounds in the north-western Pacific: a forecasting method for fishing ground locations

The relationships between fishing ground locations of Pacific saury (Cololabis saira) and the two Oyashio fronts, the offshore front between 146^oE and 155^oE and the coastal Oyashio intrusion, before the saury fishing season, were examined using data from 1971 to 1991. Interannual geographical shifts of both the offshore Oyashio front and saury fishing grounds had a dominant interdecadal fluctuation. In years when the offshore front shifted north (south), the fishing grounds were formed relatively nearshore (offshore). When the offshore front shifted north, the fishing grounds were formed further nearshore in years the coastal Oyashio intrusion extended south. When the offshore front shifted south, on the other hand, the southward extension of the coastal intrusion did not necessarily cause formation of coastal fishing grounds. These results showed that locations of the fishing grounds depend not only on local and instantaneous oceanographic environments around the fishing grounds, but also on oceanographic conditions over an extensive range of the Oyashio area. This might indicate that the ecology of the saury's northward migration, through mixed water regions between the Kuroshio and Oyashio fronts in spring and summer, has a close relation to the shift of the offshore Oyashio front over a time range of months. A practical forecasting method for locations of saury fishing grounds is proposed based on the oceanography before the fishing season.