Status of giant clam resources around Okinawa‐jima Island,Ryukyu Archipelago,Japan

1. Giant clams provide and support valuable functions to coral reefs, as well as represent a sustainable resource for traditional fisheries throughout the Indo‐Pacific region. The Ryukyu Archipelago (southern Japan) is known to be the northern latitudinal limits of giant clam distribution, but there is only limited information in the literature regarding species diversity, status, and distribution in this region.
2. In this study, we report findings from a rapid survey in 2016, the first of its kind for the Ryukyu Islands, to determine species distribution and abundance of giant clams (tridacnines) around Okinawa‐jima Island.
3. Results indicate the presence of four species with an overall density of 5.03 per 100 m², from most to least abundant: Tridacna crocea, Tridacna maxima, Tridacna squamosa, and Tridacna noae. The previously reported species Tridacna gigas and Hippopus hippopus were both absent from the surveys. The densities and distributions of tridacnines varied among species and sites, which are likely attributable to efforts in replenishing and protecting stocks of selected species.
4. The most abundant species, T. crocea, is an important fishery species in Okinawa, and has been widely cultured and restocked to augment depleted populations. In comparison, restocking efforts for less popular species, such as T. squamosa, have been limited, and their current sizes and numbers suggest recruitment constraints.
5. Given the importance of the giant clam fishery in this region and the current declines of various species (except T. crocea), further regulations should focus on the protection of larger and mature clams that function as broodstock necessary to maintain spawning and natural recruitment.

     

庙岛群岛药用植物区系及多样性研究

据调查统计,庙岛群岛有野生药用植物79科245属386种,其中有蕨类植物5科6属9种,裸子植物2科2属2种,被子植物72科237属375种。同时,对该地区野生药用植物的区系进行了研究,结果表明区系具有典型的温带性质;在各种地理成分中,北温带成分占32%,居首位,泛热带成分次之,占20.2%,说明该区系具有一定的热带亲缘。种的生活型中,一年生植物、地面芽植物和高位芽植物占优势,隐芽植物较少,地上芽植物最少。     

Using fishers’ ecological knowledge to assess the status and cultural importance of sawfish in Guinea‐Bissau

1. Sawfishes have declined dramatically in West Africa and may be extinct throughout much of their historical range. Guinea‐Bissau is considered to be one of the last remaining places in West Africa where sawfish persist.
2. Fishers’ ecological knowledge (FEK) can provide valuable baseline data, which can be used to direct scientific studies, in situations where information is scarce or lacking and can also provide insight into local attitudes towards species of interest. Interview surveys were used to collect FEK data on the past and current range of sawfishes within Guinea‐Bissau waters, perceived causes of the decline amongst fishermen, and the cultural importance of this species to Bissau‐Guineans.
3. Data were collected from 274 respondents, of whom 85% could identify a sawfish from an image. The majority of respondents reported to have last seen a sawfish in the 1980s, although this varied considerably by region, and 30% of respondents in the south had seen or captured sawfishes in the past decade up to and including 2012.
4. Overfishing or excessive fishing pressure was most frequently cited as a perceived cause for the decline in sawfish, followed by shark finning and overseas fishermen. The sawfish is primarily of cultural importance in the Bijagos Islands, where it is central to many traditional ceremonies.
5. This information provides valuable insight into the cultural importance of sawfish to Bissau‐Guineans and their concerns in relation to the sustainability of their local fishery resources. Information on recent catches will be useful for directing future work to locate and protect remaining sawfish in Guinea‐Bissau.

Copyright © 2013 John Wiley & Sons, Ltd.     

庙岛群岛野生观赏植物资源与利用

根据调查统计,庙岛群岛有野生观赏植物62科155属198种,按观赏特性可分为观叶、观花、观果、观花与观果、地被及垂直绿化6类,并对其开发利用现状进行了探讨,对该地区野生观赏植物的区系进行了研究。结果表明,区系为典型的温带性质;种的生活型中,高位芽植物（32.3%）和地面芽植物（30.3%）占优势,1年生植物（19.2%）和隐芽植物（16.2%）较低,地上芽植物最少（2.0%）。     

舟山海岛野生观赏植物的应用

通过对舟山群岛植物资源的调查研究,分析了耐盐碱植物、耐干旱瘠薄的阳性植物、耐阴植物和彩叶植物等海岛野生观赏植物的资源种类和特点,论述它们在营建沙滩风景林、海岛植物群落及园林绿化中的应用前景和方法.针对目前舟山海岛野生观赏植物开发应用不足,缺乏地方特色等现状,提出了合理开发野生观赏植物,筛选沙滩风景林树种和规划营造海岛群落景观等方面的建议,特别强调应采用海岛特色植物以体现海岛城市风格.参10     

马鞍列岛海洋特别保护区斑头六线鱼的摄食习性

为了解马鞍列岛海洋特别保护区岩礁生境斑头六线鱼的摄食习性,基于2009年3月~2010年2月多网目组合刺网调查获取的252尾斑头六线鱼样本,研究了斑头六线鱼的饵料组成和摄食策略。结果表明斑头六线鱼主要摄食端足类的麦秆虫,是以麦秆虫为主食的狭食性鱼类。斑头六线鱼摄食种类随季节变化,春季、夏季和秋季主要摄食端足类,表现为狭食性的摄食特性,冬季主要摄食蟹类、腹足类和其他类,表现为广食性的摄食特性。     

Pueruli of Panulirus longipes bispinosus (Crustacea, Decapoda, Palinuridae) stranded on the beach of Kuroshima Island, Ryukyu Archipelago, southern Japan

ABSTRACT: Stranded organisms were observed on the sandy beach of Kuroshima Island, Ryukyu Archipelago, in the early morning of 28 January 1993. Stranded organisms of 525 individuals were classified into 74 species. These organisms included 13 individuals of Panulirus pueruli, which were identical to P. longipes bispinosus. Kuroshima Island is located near Ishigakijima and Iriomote islands, Ryukyu Archipelago, where coral reefs develop. Coral reefs are common and develop in the Ryukyu Archipelago, southern Japan, with the exception of Yakushima and Tanegashima islands. Panulirus japonicus in Japanese waters has not been found in coral reef regions where P. longipes bispinosus are mainly found. The present study describes and identifies to species level puerulus specimens that were stranded on the beach of Kuroshima Island.     

The conservation status of Townsend's shearwater Puffinus auricularis auricularis

Townsend's shearwater (Puffinus auricularis auricularis) is an endangered seabird endemic to the Revillagigedo Archipelago. It nested on Socorro, Clarion, and San Benedicto Islands. It was extirpated by the Barcena volcano on San Benedicto in 1952, and there are no recent indications of nesting. Introduced mammals—pigs and rabbits—preyed on them and destroyed habitat at Clarion; shearwaters were extirpated by 1988, and no breeding attempts have been reported since. Our results confirm that Socorro holds the last breeding grounds. We found breeding colonies above 800 m and a minimum population of 1100 individuals. This represents a significant reduction in distribution and population size. Intensive cat predation at Socorro could potentially kill ca. 350 females per season, and sheep progressively destroy nesting areas. Population projections suggest that demographic instability could occur in less than 100 years under severe predation and habitat degradation. Only low predation rates would allow population persistence for more than 150 years in spite of a declining population. Thus, the immediate eradication of all introduced mammals is necessary to prevent the extinction of this seabird.     

舟山海岛普陀樟等3种特有树种种质资源清查

通过清查,发现普陀樟Cinnamomum japonicum var. chenii集中分布于舟山市普陀区所辖范围内的洛伽山、朱家尖岛以及以朱家尖、桃花、六横岛为中心的毗邻悬水小岛上,种质资源比较丰富,全市共有结果母树1.2万余株,大年种子产量有1500 kg左右。舟山新木姜子Neolitsea sericea分布在普陀区的朱家尖、桃花、普陀山和定海区的大猫岛,其分布特点是孤立,散生,且范围极小,无成片分布,共有结果母树300余株,种质资源较为贫乏,加之不合理的采种,迄今大年种子产量仅为100 kg。南京椴Tilia miqueliana分布范围更是有限,主要分布在桃花岛蚂蝗坑和定海区大猫岛茅草屋冷坑,呈群落分布,共有结果母树170余株,每年种子产量极少,能采到的种子只有0.25 kg左右。表3参12     

妙道山高山沼泽植被的研究

岳西妙道山高山沼泽植被生于海拔1 000 m左右的山谷林下,总面积1.4 hm2.群落共有维管束植物90科180属258种,含种类较多的科有蓼科、蝶形花科、蔷薇科、莎草科、菊科、禾本科等,林下以湿生草本为主,多成片分布,形成高山草甸.叶级为中等叶,生活型有地上芽植物、地面芽植物和水生植物,分为乔木层、灌木层、草本层及层间植物.物种多样性草本层＞灌木层.妙道山高山沼泽植被研究价值高,应加强宣传和保护.