The first network of marine protected areas (MPAs) in the high seas: The process, the challenges and where next

Marine protected areas (MPAs) are increasingly being established to protect and rebuild coastal and marine ecosystems. However, while the high seas are increasingly subject to exploitation, globally few MPAs exist in areas beyond national jurisdiction. In 2010 a substantial step forward was made in the protection of high seas ecosystems with 286,200 km² of the North-East Atlantic established as six MPAs. Here a summary is presented of how the world's first network of high seas marine protected areas was created under the OSPAR Convention, the main challenges and a series of key lessons learned, aiming to highlight approaches that also may be effective for similar efforts in the future. It is concluded that the designation of these six MPAs is just the start of the process and to achieve ecological coherence and representativity in the North-East Atlantic, the network will have to be complemented over time by additional MPA sites.     

Age,growth and natural mortality of blue jack mackerel Trachurus picturatus (Carangidae) from the Canary Islands,Spain (NW Africa)

Status assessment of exploited fish populations is a general requirement to ensure sustainability of fisheries in both global and local contexts. The blue jack mackerel Trachurus picturatus (Bowdich, 1825) remains unassessed in a data-limited fishery in the eastern central Atlantic, within the waters of the Canary Islands (Spain) off the coast of northwest Africa. This is the most southwestern targeted fishery in the species’ distributional range. To obtain basic life-history information, a total of 2 472 specimens were analysed, ranging from 10.2 to 31.9 cm total length, from samples collected monthly between March 2005 and March 2006. Length–weight relationships (a = 0.0023; b = 3.418; R ² = 0.97) showed no significant difference between sexes. Deposition periodicity and coherence of the ageing criteria were verified by analysis of the monthly evolution of the otolith edge. Ages were estimated by counting annual growth rings on whole otoliths, with these fish ranging from age 0 to 6 years. The von Bertalanffy growth model, which was used to estimate growth parameters from both direct readings and back-calculated length-at-age data, gave good statistical fits. The parameters from the direct readings were: L∞ = 34.9 cm; k = 0.214 y^–1; t ₀ = ?2.545 y (R ² = 0.84), and the natural mortality rates estimated from empirical methods varied between 0.20 and 0.55 y^–1.     

中国东部海区地球物理调查及重磁场特征

中国海洋地质调查始于20世纪50年代,大致分为创业阶段、起步阶段、发展阶段、全面发展阶段和蓬勃发展阶段,经过多年的地质与地球物理调查,获取了大量的地质地球物理资料。该区磁场强度一般为±200 nT,局部达到±500 nT以上,呈NE、NNE向作带状分布,局部异常走向不一,类型多变。空间和布格重力异常总体走向为NE向,陆区以负异常为主,海区主要表现为正异常,空间重力异常值总体上为-45~+100 mGal,局部异常值可达+200 mGal以上;布格重力异常极小值为-140 mGal,极大值可达+440 mGal,局部地区分布高值异常圈闭。根据重、磁异常的幅值高低、形态展布和区域变化等特征,将重、磁异常各自划分为华北-渤海异常区、山东半岛-北黄海异常区等9个异常区,重磁场特征充分展示了中国东部海区东西分带、南北分块的构造格局。     

海洋牧场背景下的休闲渔业旅游发展模式研究

近年来随着产业融合的发展趋势显著,第一产业和第二产业开始向第三产业转型,海洋牧场建设发展过程中渔业与旅游业逐渐融合发展形成休闲渔业等渔业旅游形式。许多地区因地制宜形成了不同的休闲渔业发展模式,休闲渔业旅游发展多元化的趋势也在逐渐形成。文章对休闲渔业的概念进行了阐述,介绍了休闲渔业的产生与发展,并对我国休闲渔业的旅游模式进行归纳,提出当前休闲渔业发展存在的问题。如:发展观念滞后,缺乏长远规划;海洋休闲渔业产业结构单一;缺乏高素质的从业人员;科技、资金投入不足等。最后总结了海洋牧场背景下休闲渔业的未来发展趋势并对发展方向提出建议。     

我国无居民海岛管理现状、问题及建议

无居民海岛是我国自然资源的重要组成部分。为加快推进生态文明建设,党和国家对我国自然资源的管理提出了新的要求。文章采用问题和目标导向的研究方法,通过对我国无居民海岛管理的历史遗留问题、管理能力、管理体系和信息化建设等方面进行分析,提出了分类处置历史遗留用岛,优化精细化分类管理体系、完善海岛管理制度体系、完善海岛数据更新体系等建议,对提升我国无居民海岛管理水平,实施海洋强国战略具有重要的意义。     

东海中南部秋季游泳动物多样性及群落结构

根据2018年11月东海中南部游泳动物底拖网调查数据,对该海域游泳动物种类组成、优势种、种类多样性及群落结构进行研究。结果表明,调查共捕获游泳动物181种,其中鱼类133种,甲壳类34种,头足类14种;优势种（IRI≥500）为七星底灯鱼（Benthosema pterotum）、带鱼（Trichiurus lepturus）、麦氏犀鳕（Bregmaceros mcclellandi）、龙头鱼（Harpadon nehereus）和日本发光鲷（Acropoma japonicum）。多样性指数结果显示,东海中南部海域丰度（d）的变化范围为0.37～5.94,种类多样性指数（H′）的变化范围为0.38～2.64,均匀度（J）的变化范围为0.14～0.71。根据聚类分析结果将东海中南部海域游泳动物群落分为以90 m等深线为界的两个群组,群组间的差异主要由七星底灯鱼、镰鲳（Pampus echinogaster）、龙头鱼、黄鲫（Setipinna tenuifilis）、麦氏犀鳕等引起。BIOENV结果显示水深与游泳动物群落结构相关性最密切（r_w=0.55）。本研究结果可为类似海域游泳动物种类多样性和群落结构的研究提供参考,也可为研究海域渔业资源开发、利用与养护等政策的制定提供科学依据。     

北冰洋高纬度区域海冰及气象特征分析

基于2018年8月至2019年5月布放在北极随海冰漂流的自动气象站和温度链浮标获取的观测数据,分析了北极高纬度区域的大气特征和海冰生消过程。根据海冰的漂移轨迹分为两个阶段分析,第1阶段,海冰主要向东南漂移;第2阶段,海冰主要向东北漂移。第1阶段观测的平均气温和平均相对湿度分别为–6.6℃和93%,第2阶段观测的平均气温和平均相对湿度分别为–29.3℃和76%,第2阶段平均气压高于第1阶段。海冰的漂移轨迹主要受到波弗特高压外围气流的影响。利用自动气象站漂移轨迹计算得到海冰漂移速度,与美国国家冰雪数据中心海冰漂移速度比较显示,两者纬向速度更为接近。海冰在第1阶段以融化为主,海冰厚度略有减小,8月份海冰生长率为–0.11 cm/d;海冰的生长过程主要发生在第2阶段,1–3月生长率均超过0.9 cm/d,2019年3月海冰生长最快,平均生长率为1.3 cm/d,海冰的增长一直持续至观测结束。     

厦门东海域定置网渔获鱼类种类组成及其季节变化

2003年7月～2004年6月对厦门东部海域的定置网渔获鱼类进行采样分析．结果表明厦门东海域至少有鱼类242种，隶属于19个目81科145属，主要是沿岸近底层和底栖的小型鱼类．以鲈形目种类最多，共计127种，占总数的52．5％、经济种类有116种．主要优势种有：青鳞小沙丁鱼、孔鳞小沙丁鱼、斑鲦、马拉邦虫鳗、裸鳍虫鳗、中华须鳗、前鳞鲻、眶棘双边鱼、多鳞鳝、皮氏叫姑鱼、短棘银鲈、列牙垒幸4、黄斑蓝子鱼、褐蓝子鱼、锯塘鳢、锻虎鱼类、褐菖鲇、绿鳍鱼、鳄鲡、卵鳎、中华单角鲍等．渔获种类在秋季及冬初最多，夏季较多，而冬末和春初最少．渔获种类的季节变化比较明显，与海洋表层水温变化有关，种类的月更替率比较高．     

Lobster trap impact on coral reefs: Effects of wind‐driven trap movement

Commercial fishers report finding their lobster traps often great distances from their original location following major hurricanes. But traps also move during lesser wind events, such as during winter cold fronts. To assess trap impact on coral communities following winter storms, lobster traps were placed in hardbottom and reef habitats commonly used by commercial fishers in the Florida Keys, United States. Trap movement, percentage benthic faunal cover, and benthic faunal damage were assessed after 26 wind events occuring over three winters. Traps moved when storms with sustained winds greater than 15 knots (27.8 km/h) persisted for more than 2 days. Winter storms above this threshold moved buoyed traps a mean (±SE) distance of 3.63 ± 0.62 m, 3.21 ± 0.36 m, and 0.73 ± 0.15 m per trap and affected a mean area of 4.66 ± 0.76 m², 2.88 ± 0.29 m², and 1.06 ± 0.17 m², per trap at 4‐m, 8‐m, and 12‐m depths, respectively. Unbuoyed traps, simulating derelict traps, moved a mean distance of 0.43 ± 0.08 m and 0.44 ± 0.02 m, and affected a mean area of 0.77 ± 0.06 m² and 0.90 ± 0.08 m² per trap at 4‐m and 8‐m depths, respectively. Injuries caused by trap movement included scraped, fragmented, and dislodged sessile fauna, resulting in significant damage to stony coral, octocoral, and sponges. Overall, sessile fauna cover along the trap movement path was reduced from 45% to 31%, 51% to 41%, and 41% to 35% at the 4‐m, 8‐m, and 12‐m sites, respectively. Because of the large numbers of traps deployed and reported lost each season, damage to sessile fauna and loss of benthic faunal cover caused by traps needs to be considered to effectively protect coral reefs and manage essential fishery habitat in the future.     

Geochemical overview and undiscovered gas resources generated from Hamitabat petroleum system in the Thrace Basin,Turkey

Since the first drill in 1957, three oil, 19 gas and condensate fields have been discovered in the Thrace Basin. However, any petroleum system with its essential elements and processes has not been assigned yet. This study consists of two parts, (1) geochemical overview of the previous work in order to get a necessary help to construct a petroleum system and (2) calculation of quantitative undiscovered hydrocarbon resources generated from this system. An extensive overview study showed that the primary reservoir and source rocks in the Thrace Basin are the Middle Eocene Hamitabat sandstones and shales, respectively, hence it appears that the most effective petroleum system of the Thrace Basin becomes the Hamitabat (!) petroleum system. Currently, 18.5 billion m³ of in-place gas, 2.0 million m³ (12.7 million bbl) in-place waxy oil as well as minor amount of associated condensate were discovered from this system. This study showed that the regional distribution of the oil and gas fields almost overlapped with the previously constructed pod of active Hamitabat shales implying that short and up-dip vertical migration pathway of hydrocarbons from the source to trapping side was available. Thermal model demonstrated that hydrocarbon generation from the Hamitabat shales commenced in the Early Miocene. The amount of quantitative gas generation based on the mean-original TOC = 0.94 wt%, mean-original HI = 217 HC/g TOC and the volume of the pod of active source rock = 49 km³ is approximately 110 billion m³ of gaseous hydrocarbons that results in a high generation–accumulation efficiency of 17% when 18.5 billion m³ of already discovered hydrocarbons are considered.