海洋遥感技术在海洋渔业及相关领域的应用与研究

自20世纪70年代始,科研人员将遥感技术应用于海洋渔业及其相关领域的研究,将各类卫星遥感所获得的数据对海洋水温、海流、光、盐度、溶解氧、气象因素、水深、海底地形、饵料生物等进行了由定性到定量的分析,并将所得结果用于指导渔业生产、促进渔业研究、预警海洋灾害等方面,所起作用非传统调查方法能为。因此,遥感技术在海洋渔业及其相关领域正在发挥着越来越大的作用,并预示着广阔的应用前景和巨大的应用潜力。本文综述了遥感技术在海洋生态系统相关要素和渔场变动、大型动植物分布、海况监测、海洋生态污染及灾害监测等方面应用与研究进展,并对海洋遥感信息在我国海洋渔业领域的应用研究前景进行了分析。     

海洋渔业遥感技术及其渔场渔情应用进展

遥感已成为渔情分析和预报的重要技术手段之一。文章回顾了国内外渔业遥感技术的发展,对国外遥感渔场渔情分析应用现状进行了简要的评述,并详细介绍了我国在海洋渔场环境分析和渔场预报服务方面的研究进展。对我国今后的渔业遥感应用研究提出了几点建议。     

Remote sensing and geographical information systems: Their past, present and future use in global marine fisheries

Historically, the fishing community (e.g., fishermen, resource managers) has used remotely sensed products either in the form of direct Automatic Picture Transmission (APT) reception on a ship or FAX charts transmitted from land-based stations. Both these products have severe limitations within the context of near real-time support/management of an operational fishery. Moreover, relatively little use of geographical information systems (GIS) technologies has been made by either the fishing industry, fishery resource managers, or by the general oceanographic community. This latter omission is unfortunate because GIS has the potential to overcome two long-standing problems associated with satellite-directed fisheries: 1) the absence of information due to clouds; and 2) the general lack of support for nonpelagic fisheries. This report gives the background, motivation, and essential design elements for use of a combined remote sensing/geographical information system (RS/GIS) in an operational fishery and illustrates how a combined RS/GIS approach can be used to mitigate some of the traditional limitations in satellite-directed fisheries. Finally, an attempt is made to provide some possible directions this new technology may take during the 1990s.     

水产养殖水体遥感动态监测及其应用

以安徽省巢湖市为实验区,以国产高分一号(GF-1)和资源三号(ZY-3)高分辨率遥感影像为数据源,以NDWI和纹理特征作为分类特征,联合随机森林、支持向量机和BP神经网络3种分类方法,发展了一种集成分类模型,用于提取养殖水体信息,并进行阴影剔除和形态学处理。结果表明,该集成分类模型适用于提取养殖水体信息,总体精度为97.4%,Kappa系数为0.87,漏分误差为3.7%,错分误差为6.4%,相比单个模型精度明显提高;针对GF-1影像的增强阴影水体指数,对山体阴影和城市建筑阴影的剔除效果明显,较大程度上避免了阴影对水体提取的干扰;实验区养殖水体的遥感动态监测应用发现, 2016年相比2013年水产养殖面积增加6.9%。该研究理论与技术成果的应用,有助于及时掌握养殖水体的时空分布及动态变化,快速提升中国渔业管理的信息化和科学化水平。     

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     

卫星遥感和GIS技术在海洋渔业资源研究中的应用

卫星遥感和地理信息系统（geographic information system,GIS）技术为海洋渔业资源研究提供了新的技术和方法,已在海洋渔业领域得到广泛应用。文章从海表温度、叶绿素浓度2个方面综述了遥感在海洋渔业环境因子方面的应用,简单介绍了GIS技术以及遥感和GIS技术的结合在海洋渔业资源研究中的应用。并在此基础上讨论了遥感和GIS技术在海洋渔业应用中需要注意的几个问题。     

卫星遥感在海洋监测中的应用

卫星遥感具有覆盖面积大、快速、全天时和全天候的工作能力。通过对卫星遥感所获得的海洋水温、水深、气象因素等数据进行分析,可以用于指导渔业生产、海洋灾害预警、海洋生态污染及灾害的监测,有着广泛的应用前景。     

北斗船位数据提取拖网捕捞努力量算法研究

传统的捕捞努力量统计耗时费力,并且存在延时,不能及时了解宏观的捕捞强度,本研究以象山港拖网渔船为研究对象,选择安装北斗终端的1 508艘渔船,对北斗卫星船位监控系统所获取的渔船船位、航向、航速等信息进行分析挖掘,获得捕捞强度。根据航速统计获得每艘渔船处于捕捞状态的航速阈值,如拖网船300791捕捞状态船位点阈值的航向差最小和最大分别是-50和52°,航速最小和最大分别是0.9和2.0 m/s,两者结合判断捕捞状态点,再采用过滤窗修正,在各渔区格网计算一段时间内渔船捕捞状态点的累计捕捞时间,其值与渔船功率的乘积获得捕捞努力量,物理单位为kW·h,并制作累计捕捞kW·h的格点图和插值图。该方法具有实时、大范围、快速、分辨率高的特点,能够很好地服务于渔业资源保护。     

南极磷虾的时空分布及遥感环境监测研究进展

环绕南极大陆的水圈部份为南极水域（南大洋）,面积约3．6×10^6km^2,具有丰富的海洋生物资源,目前已知鱼类多达200余种。南极磷虾是可以直接开发利用的渔业资源,据估计,每年可捕获的资源量约1．5×10^8t,相当于世界渔获量的总和,是当今可利用的最大的渔业潜在资源^[1]。     

渤、黄、东海海洋初级生产力的遥感估算

通过对多年的东海、黄海南部实测海洋初级生产力与环境数据的分析，采用非线性最小二乘法，得到海洋初级生产力的遥感估算模型。利用从2000年1月-12月的SeaWiFS数据反演得到的叶绿素a浓度、透明度、辐照度数据，以及同期的NOAA数据反演得到的海表水温数据，通过该模型，提取出我国海区的海洋初级生产力的时空分布信息。结果表明，在东海、黄海和渤海初级生产力季节变化明显，在东海，最大初级生产力的月份为5月，最小月份为2月。而在黄海和渤海，最大初级生产力的月份为8月，最小月份为2月。在大洋区，初级生产力的季节变化相对较小。与相关的文献资料比较该模型能较好地反映渤、黄、东海的海洋初级生产力的时空分布信息及其变化情况。由于我国海区大部分是二类水体，水光学、水文特性比较复杂，叶绿素浓度等遥感产品的精度有待进一步的提高，叶绿素浓度及其剖面分布估算不准，对整个模式的精度影响很大。同时由于所用的实测数据及其分布区域、时间的限制，以及没有同步数据，对该模型的结果还要经过进一步的检验。     

Improving bivalve fishery management: The development of a tool to forecast bivalve reproductive season based on environmental data from satellite remote sensing observations

Donax trunculus is a much‐appreciated commercial clam whose natural populations have been overexploited in southern–western Spain during the last decades. In order to control the decrease of natural beds, local governments establish annual closed seasons based on socioeconomic reasons, such as economic necessity or tourism interest. The objective of this study was to develop an efficient tool for predicting gonadal stages based on environmental condition data. This tool will allow for an improvement in fishery management since in this manner the closed season can be based on the reproductive cycle. The natural population's reproductive cycle was studied for more than 2 years. The obtained gonadal and condition indexes (GI and CI) values were statistically related to environmental conditions, specifically surface seawater temperature (SST) and chlorophyll‐a (Chlo‐a) levels with these data being provided from satellite remote sensing observations (SRS). The best statistical relationship was obtained between GI and the SST registered 60 days before bivalve sampling (SST‐60). The regression equation allows for an estimate of GI value based on the SST‐60 and, as each value is related with one gonadal stage (resting, maturation, ripe), for prediction of the reproductive cycle. Therefore, the closed season can be established when most of the population is in the ripe stage and can be adjusted taking into account the possible temperature variations across the years. For ease of use, GI values estimated with this tool have also been converted using different colours onto a map of wedge clam reproductive stages in its natural beds.     

Impact of aquaculture on mangrove areas in the northern Pernambuco Coast (Brazil) using remote sensing and geographic information system

The conversion of mangrove areas into shrimp farming ponds has been indicated as the main activity responsible for the reduction in the area of this ecosystem along the northeastern coast of Brazil. The present study was conducted using remote sensing methods and a geographical information system with the aim of quantifying the participation of this activity in the reduction of the mangrove areas along the northern coast of the State of Pernambuco (northeast, Brazil), where shrimp farming has been implanted in last recent years. From 1973 to 2005, there was reduction of about 2.052 ha of mangrove, 197 ha of which were converted into shrimp ponds. Thus, the real contribution of shrimp farming to this reduction was just 9.6% of the total area. Other anthropogenic activities, such as agriculture, urban expansion and tourism, contributed greatly to the reduction in the mangrove areas along the northern coast of the State of Pernambuco.     

Habitat characteristics of skipjack tuna (Katsuwonus pelamis) in the western North Pacific: a remote sensing perspective

Skipjack tuna habitat in the western North Pacific was studied from satellite remotely sensed environment and catch data, using generalized additive models and geographic information systems. Weekly resolved remotely sensed sea surface temperature, surface chlorophyll, sea surface height anomalies and eddy kinetic energy data were used for the year 2004. Fifteen generalized additive models were constructed with skipjack catch per unit effort as a response variable, and sea surface temperature, sea surface height anomalies and eddy kinetic energy as model covariates to assess the effect of environment on catch per unit effort (skipjack tuna abundance). Model selection was based on significance of model terms, reduction in Akaike’s Information Criterion, and increase in cumulative deviance explained. The model selected was used to predict skipjack tuna catch per unit effort using monthly resolved environmental data for assessing model performance and to visualize the basin scale distribution of skipjack tuna habitat. Predicted values were validated using a linear model. Based on the four‐parameter model, skipjack tuna habitat selection was significantly (P < 0.01) influenced by sea surface temperatures ranging from 20.5 to 26°C, relatively oligotrophic waters (surface chlorophyll 0.08–0.18, 0.22–0.27 and 0.3–0.37 mg m^?3), zero to positive anomalies (surface height anomalies 0–50 cm), and low to moderate eddy kinetic energy (0–200 and 700–2500 cm² s^–2). Predicted catch per unit effort showed a trend consistent with the north–south migration of skipjack tuna. Validation of predicted catch per unit effort with that observed, pooled monthly, was significant (P < 0.01, r² = 0.64). Sea surface temperature explained the highest deviance in generalized additive models and was therefore considered the best habitat predictor.     

基于遥感的黄海中南部越冬鳀资源密度分布与环境因子的关系研究

基于遥感和GIS(Geographic information system)技术,利用2000~2015年的底拖网调查数据和海表温度、叶绿素a浓度以及海水温度梯度等遥感数据,在定性分析黄海中南部越冬鳀(Engraulis japonicus)资源密度分布与环境因子关系的基础上,利用时空和环境因子构建GAM (Generalized additive model)模型进行定量分析。结果显示,时空因子(年、下网时间、经度和纬度)和环境因子对越冬鳀资源密度的总偏差解释率为44.76%,其中,时空因子对其的影响均显著,以空间因子影响最大,对总偏差的解释率为35.4%;环境因子中,水深、海表温度和温度梯度对其影响显著,而叶绿素a浓度影响不显著;越冬鳀分布的最适海表温度、叶绿素a浓度和海表温度梯度范围分别为7~11℃、1.2~2.3 mg/m3和0.7~2.5℃。研究结果对环境变动下的渔业管理具有重要意义。     

基于SNPP/VIIRS夜光遥感数据的东、黄海渔船时空分布及其变化特点

基于SNPP (Suomi national polar-orbiting partnership)卫星的VIIRS (visible infrared imaging radiometer suite)传感器获取的2013年1月至2017年12月夜光遥感渔船数据,对东、黄海渔船时空分布及其变化特点进行了研究。结果表明:(1)遥感获取的渔船数据基本能够反映中国东、黄海捕捞活动和渔业资源时空分布变化的特点,如2月受天气和中国春节的影响,南、北渔场渔船分布范围大幅减少, 8月南渔场和10月北渔场受当年生渔业资源补充及近海索饵群体集聚的影响,渔船分布范围及数量均达到最大值;同时,渔船时空分布及重心变化也反映了黄海暖流、台湾暖流、沿岸流及长江冲淡水等对渔业资源时空分布的影响。(2)渔业政策实施的效果在夜光遥感渔船数据中有很好的体现,在禁渔期间,船次数有明显减少,但捕捞活动并没有完全消失,仍可能存在违法捕捞行为。(3)南渔场年船次总数呈下降趋势,南、北渔场渔船空间分布重心均呈西移趋势,可能与渔业资源量及空间分布变动等因素有关。受天气等因素影响,遥感数据可能存在一定问题,但研究结果表明, SNPP/VIIRS夜光遥感数据仍可为中国近海灯光诱捕作业的监测提供有效的数据支持。