First attempts towards the restoration of gorgonian populations on the Mediterranean continental shelf

1. In the Mediterranean Sea, gorgonians are among the main habitat‐forming species of benthic communities on the continental shelf and slope, playing an important ecological role in coral gardens.
2. In areas where bottom trawling is restricted, gorgonians represent one of the main components of trammel net bycatch. Since gorgonians are long‐lived and slow‐growing species, impacts derived from fishing activities can have far‐reaching and long‐lasting effects, jeopardizing their long‐term viability. Thus, mitigation and ecological restoration initiatives focusing on gorgonian populations on the continental shelf are necessary to enhance and speed up their natural recovery.
3. Bycatch gorgonians from artisanal fishermen were transplanted into artificial structures, which were then deployed at 85 m depth on the outer continental shelf of the marine protected area of Cap de Creus (north‐west Mediterranean Sea, Spain). After 1 year, high survival rates of transplanted colonies (87.5%) were recorded with a hybrid remotely operated vehicle.
4. This pilot study shows, for the first time, the survival potential of bycatch gorgonians once returned to their habitat on the continental shelf, and suggests the potential success of future scaled‐up restoration activities.

     

Genetic differentiation between and within ecotypes of pike (Esox lucius) in the Baltic Sea

1. Aquatic systems often lack physical boundaries for gene flow, but ecological and behavioural barriers can form surprisingly fine spatial scale genetic patterns that challenge traditional, large scale management. To detect fine spatial scale structures, understand sources of intraspecific diversity, and design appropriate management plans requires identification of reproductively isolated units.
2. This study reports on genetic differentiation in pike (Esox lucius) within a coastal area stretching 55 km from south to north in the central Baltic Sea. Pike is here an economically and ecologically important top predator that has declined in abundance. However, population structures have mostly been studied on large spatial scales, and without considering the potential for genetic divergence between the sympatric anadromous fresh water and the resident brackish water spawning ecotypes.
3. To this end, 487 individuals from the east coast of Sweden and the island of Öland, representing sympatric anadromous and resident spawning individuals, categorized to ecotype based on spawning location or otolith microchemistry, were genotyped for 10 microsatellites and used to test for divergence between ecotypes. Furthermore, divergence between regions (island/mainland), neighbouring spawning locations (n = 13) and isolation by distance within and between regions were evaluated for the anadromous ecotype.
4. The results revealed strong genetic differences between regions, between spawning locations separated by as little as 5 km and the first evidence of genetic differentiation between resident and anadromous ecotypes; despite a high dispersal capacity of pike and a high connectivity within the study area. The signatures of isolation by distance indicated that connectivity among populations differed between regions, probably reflecting availability of spawning habitats.
5. To safeguard against the challenges and uncertainties associated with environmental change, adaptive conservation management should aim to promote high intra‐population functional genetic diversity without compromising the continued integrity and coexistence of the different ecotypes and of locally adapted sub‐populations.

     

A facial recognition tool and legislative changes for improved enforcement of the CITES Appendix II listing of the humphead wrasse,Cheilinus undulatus

1. Humphead, or Napoleon, wrasse, (Cheilinus undulatus), is a large reef fish naturally vulnerable to over‐exploitation and highly prized as luxury seafood. It is predominantly consumed in Hong Kong and mainland China. Hong Kong is the global trade hub for this species. In 2004 (effective 2005), the humphead wrasse was listed on the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) Appendix II that substantially improved understanding and management of the species although illegal, unregulated and/or undocumented trade (IUU) continues.
2. To understand patterns of trade in humphead wrasse, evaluate implementation of the CITES listing and identify ways to tackle IUU, especially in Hong Kong, data from multiple sources, including government databases between 1999 and 2017 and independent retail surveys between 2014 and 2017, were compiled.
3. IUU trade into and through Hong Kong was detected, but declined following increased government enforcement in 2016. Nonetheless, fish numbers on sale continue to exceed imports with CITES permits and mainland China only sparsely reports imports of the species. Approximately 0.5–1.5 metric tonnes were traded internationally annually.
4. Several legislative loopholes undermine enforcement into and within Hong Kong, including poor oversight of live fish carrier vessels and air imports, excessively long validity period for Licences to Possess in the city, non‐compliant traders, and legislative exemptions or omissions. The introduction of a ranched fish category in 2018 by Indonesia created additional challenges. More intelligence and risk analyses could help enforcers target their work.
5. A major enforcement challenge is the inability to distinguish legally from illegally imported fish within Hong Kong. To improve fish tracking, identifying individuals using their complex facial patterns as fingerprints was explored; proof‐of‐concept was demonstrated using a mobile phone application: Saving Face. Facial marks were determined to be long‐lasting and different enough to distinguish among multiple individuals.

     

Occurrence patterns of African manatees,conflicts with humans,and local perception in the Southern Korup Area,Cameroon

1. The African manatee has been poorly studied throughout its range and is heavily hunted. This study aimed at discerning patterns in manatee sightings and emerging conflicts with humans, as well as the local perception of manatees, outside the southern periphery of Korup National Park, Cameroon.
2. The study investigated whether patterns in manatee sightings and manatee‐related conflicts differ between aquatic systems in southern Korup, and which demographic variables determine perceptions of the manatee in the study area. For this purpose, the study used a three‐stage stratified random sampling design with a structured questionnaire to survey 101 local fishers.
3. The reported patterns of manatee sightings and manatee‐related conflicts were as follows: in the Nyangorobe River during the wet season only, where crop raiding and net destruction by manatees were reported; in the Ndian River and the mangrove estuary only during the dry season, where fish theft and net damage were reported; and in the Moko River during both seasons, where crop raiding, fish theft, and net destruction were reported. Reducing these conflicts is likely to increase local support for the conservation of manatees, because fishermen kill them in response to net destruction and fish loss.
4. Most reported sightings were at waterway intersections and river bends, suggesting that waterway connectivity is important to manatees for dispersal, foraging, and escape from danger.
5. The log‐odds probability of negative perception decreased significantly with awareness of manatee protected status but increased with age and primary or higher education level. These findings have implications for community outreach focused on raising awareness of the importance of manatee conservation by schoolchildren and the public.

     

基于道路载荷特征的整车试验场耐久性评价方法

为了获得整车试验场各路况对底盘各零部件的对应考核情况,以国内某整车大型试验场为研究对象,通过将采集到的试验场载荷分解,获得试验场各子路况的载荷时间历程。通过分别以底盘零部件各测点为基准和以试验场各路况为基准对比分析各路况对应各测点的损伤,可得到试验场路况考核表。针对考核表中不同路况考核部件的相似性,对比分析其各路况考核各部件的极值、变程、RMS、损伤,根据分析结果优化此前得到的试验场各路况考核表。此方法可为整车试验场耐久性评价提供一定参考。     

帽儿山地区脂松种源试验林生长指标分析

引进优良的外来树种可以丰富本国或本地区林业建设的树种资源,增加木材产量和林产品的种类。通过对引进的美国东部7个脂松种源进行试验,得出更适宜栽植区的种源。在树高方面,较好的4个种源依次为MIDC(Dickenson County,Michigan)、MNCNF(Chippewa National Forest,Minnesota)、MIMC(Manistee County,Michigan)和WIOC(Oneida County,Wisconsin);2004年高生长较好的4个种源依次为WIOC、MIDC、MIMC和MNCNF;2005年高生长较好的4个种源依次为MIDC、MIMC、MNCNF和WIOC;地径较好的4个种源依次为MIDC、WIOC、MIMC、MNCNF。该4个种源间各项生长指标差异不显著;在保存率方面,7个种源间差异不明显。     

细分外推与模糊预测在近海水质非线性时序处理中的比较分析

近海水质非线性时间序列通常由于采集范围大、时间间隔长带有一定震荡性和模糊性,这使得对其进行分析与预测有一定的难度。本研究中以某近海水质指标磷酸盐(PO3-4-P)、硝酸盐(NO-3-N)、亚硝酸盐(NO-2-N)、铵盐(TNH+4-N)和硅酸盐(Si O2-3-Si)所形成的5种时间序列为例,采用逼近细分模式导出的细分外推法和多参考加权数据的模糊预测法对近海水质时序预测进行了比较分析,并通过图形与误差计算比较了两种方法的异同。结果表明:采用细分外推法预测序列在整体形状上能更好地逼近初始时序,而模糊预测法在整体逼近精度上占有优势。本研究中提出的预测比较方法可为同类问题的预测与模型选取提供参考依据。     

福建省内陆捕捞渔具的作业类型及其数量组成分析

本文根据2009年8月至12月福建省捕捞业渔具渔法普查资料,分析整理了福建内陆地区捕捞业渔具渔法现状调查数据.结果表明:福建内陆地区捕捞渔具有刺网类、钓具类、笼壶类、拖网类、张网类、陷阱类、耙刺类、地拉网类、敷网类、掩罩类、抄网类和杂渔具等12个类别、21种作业型式、渔具总数量123204张(个、顶等).按渔具类别划分...     

Square‐mesh codend length and selectivity in southeastern Australian stow nets

Abstract The relationship between the amount of square mesh in codends and selectivity was investigated for an Australian penaeid stow‐net fishery. Three lengths (3, 2 and 1 m) of square‐mesh codend made from 27‐mm mesh hung on the bar were alternately tested with a conventional 34‐mm diamond‐mesh design during two covered‐codend experiments. Compared with the conventional codend, the square‐mesh configurations incrementally selected school prawns, Metapenaeus macleayi (Haswell) across narrower selection ranges (SR) and mostly at greater sizes at 50% retention (L₅₀), while retaining fewer fish. Irrespective of the mesh configuration or square‐mesh codend length, there were significant differences between experiments (attributed to water flow) and impacts of catch weight on the selectivity of school prawns. Both variables had a negative relationship with L₅₀, while water flow similarly affected SR. This study reaffirms the utility of square‐mesh codends as a key input control for managing the selectivity of penaeid‐catching gears.     

我国玻璃钢渔船发展历程及建造工艺技术

介绍了我国大陆及台湾玻璃钢渔船的发展历程及台湾玻璃钢渔船迅速发展所采取的措施,概要介绍我国玻璃钢渔船相关技术法规建设及真空树脂导入成型工艺技术的应用情况及存在的问题,探讨了今后的研究方向。