Management of the precious coral fishery in Taiwan: Progress and perspectives     

Chih-Shin Chen 《Marine Policy》2012,36(3):623-629

Precious corals have been commercially exploited because of their legendary and cultural importance for many centuries in the Mediterranean and for almost one century in the Northwest Pacific. Although the precious coral fishery in Taiwan dates back to the 1920s, relevant studies on biology and ecology of resources are relatively scarce. The management of the precious coral fishery in Taiwan was officially instituted in January 2009, when data on the catch and effort of the fishery were recorded. In this study, the catch-effort data of the fishery were examined to explore the temporal and spatial patterns in composition and abundance of Corallium and Paracorallium spp. around Taiwan. A total landing of 3233.0 and 2906.8 kg precious corals were recorded for 2009 and 2010, respectively. Less than 5% of those amounts were from live colonies. A high proportion of fossilized colonies in the catch reflect the non-selective nature of the fishing gear; however, the factors that cause colonies to collapse are not exclusive to the impact of the fishery. Momo coral was dominant in the production for both years, followed by Miss coral. The total production of precious corals correlated positively with fishing efforts, while a weak relationship was found between the production of live colonies and fishing efforts. The fishing efforts mainly aggregated in designated fishing ground A (DFG-A) for both years, while the production of live colonies mainly occurred in DFG-E. The monthly occurrence rate of live colonies decreased over the past 2 years. Although fluctuating significantly, the CPUE of dominant species exhibited an apparent decreasing pattern. High aggregation of the fishing efforts in specific regions and low numbers of live colonies in the production should be carefully taken into account when amending management regulations in the future. The establishment of marine protected areas, in addition to the strict controls that already apply, should be considered to not only sustain the population structure of the sessile animals but also their function in the marine ecosystem.  相似文献   

基于QuickBird影像上珊瑚礁发育状况监测实验研究   总被引：2，自引：0，他引：2  

邹亚荣  梁超  朱海天 《海洋学报》2012,34(2):57-62

珊瑚礁生态系统具有很高的生物多样性和重要的生态功能。20世纪80年代以后全球范围内珊瑚礁的大面积退化引起了人们广泛的关注。利用高分辨多光谱QuickBird影像,基于珊瑚礁几何参数与发育指数对南沙典型岛礁发育进行遥感监测,在珊瑚礁体迎风面水域由破波形成的纹理特征表明了海面粗糙度与水下礁坪的发育特性。结果表明,南沙岛礁受地质与气候的影响发育程度不一,半月礁发育较好,发育指数为0.38,仙娥礁发育指数为0.27。建立几何参数等指标能够监测南沙珊瑚礁的发育状况,可对珊瑚礁的保护提供科学依据。  相似文献   

Coral communities and reefs from Guerrero,Southern Mexican Pacific     

Ramón A. López‐Pérez  Luis E. Calderón‐Aguilera  Héctor Reyes‐Bonilla  José D. Carriquiry  Pedro Medina‐Rosas  Amilcar L. Cupul‐Magaña  María D. Herrero‐Pérezrul  Héctor A. Hernández‐Ramírez  Miguel Á. Ahumada‐Sempoal  Betsabe M. Luna‐Salguero 《Marine Ecology》2012,33(4):407-416

Corals in the Eastern Pacific extend south from the Gulf of California to Ecuador and oceanic Chile, and west from Colombia to Clipperton Atoll. Nevertheless, large stretches of the Mexican Pacific remain fundamentally unstudied. Therefore, to assess the current conditions of coral communities, a coastal fringe ～300 km long (17°40′ N, 101°39′ W to 16°46′ N, 99°49′ W) was surveyed within the Southern Mexican Pacific, between 2005 and 2009. Fifteen stony coral species were identified at 13 coral communities and six Pocillopora‐dominated fringing reefs, with Pocillopora verrucosa and Pocillopora damicornis the primary contributing taxa. Reef development was identified in embayments or behind rocks or islands that offered shelter from northern and northwestern winds. Observations of Pocillopora effusus, Pocillopora inflata, Porites lobata, Pavona clavus, and Pavona varians expanded the species known geographic ranges by several degrees of latitude, suggesting reef building fauna comprised a mixture of widespread and relatively rare Eastern Pacific corals. Results indicated greater live coral cover in the Ixtapa‐Zihuatanejo area (15–73%) than in the Acapulco localities, which had high algal dominance; the reefs in the latter region exhibited high erosion. Regional differences are likely the result of long‐standing anthropogenic pressures around Acapulco since 1950, when it became an important tourist destination. This paper is the first detailed report of ecologically stressed corals and coral reefs from the state of Guerrero on the Mexican Southern Pacific coast.  相似文献   

Cladocora caespitosa bioconstructions in the Columbretes Islands Marine Reserve (Spain,NW Mediterranean): distribution,size structure and growth     

Diego‐Kurt Kersting  Cristina Linares 《Marine Ecology》2012,33(4):427-436

Today, living banks of the coral Cladocora caespitosa appear to be restricted to a few Mediterranean locations and are threatened by the escalating impacts affecting coastal areas. In this study the exceptional occurrence of the Mediterranean coral C. caespitosa in the Columbretes Islands Marine Reserve (NW Mediterranean, Spain) is characterised in terms of spatial distribution, cover area, colony size and growth rates. The coral colonies form beds and banks in rocky bottoms within a semi‐enclosed bay that offers both hydrodynamic protection and high water exchange. The spatial distribution of the C. caespitosa colonies, from 5 to 27 m depth, is highly aggregated, depending on sea‐floor morphology and showing up to 80% of substrate coverage. The annual corallite growth rates obtained through the alizarin red staining method and x‐ray image analysis are similar, and range between 2.55 ± 0.79 mm and 2.54 ± 0.81 mm, respectively. The exceptional nature of these bioconstructions is due to their cumulative cover area, which is comparable in size to the largest C. caespitosa bioconstructions described to date in Mljet National Park (Croatia, Adriatic Sea).  相似文献   

Coral Reef Bleaching at Agatti Island of Lakshadweep Atolls,India     

Ramar Vinoth  Mohan Gopi  Thipramalai Thankappanpillai  Ajith Kumar  Thirunavukarassu Thangaradjou  Thangavel Balasubramanian 《青岛海洋大学学报(英文版)》2012,(1):105-110

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Predicting sediment inputs to aquatic ecosystems across England and Wales under current environmental conditions     

A.L. Collins  S.G. Anthony 《Applied geography (Sevenoaks, England)》2008,28(4):281-294

The awareness of water quality issues has never been higher. As part of its continuing strategic diffuse pollution policy support, ADAS recently undertook to identify catchments across England and Wales that could potentially fail recently proposed suspended sediment yield targets under current environmental conditions. The total suspended sediment loads (SSL) delivered to all rivers were assumed to comprise contributions from diffuse sources in the agricultural and urban sectors, as well as from eroding channel banks and point sources represented by sewage treatment works (STWs). Diffuse agricultural sediment loss to rivers was predicted using the PSYCHIC model. Corresponding inputs from diffuse urban sources were estimated on the basis of an Event Mean Concentration (EMC) methodology. Channel bank sediment inputs were calculated using a prototype national scale model, while point source sediment contributions were based on a register of consented effluent discharges. Modelled SSL were validated (r²=68%) against PARCOM data (1999–2003) for the delivery of sediment to different regions of the UK maritime area. The results of the validation were considered to be realistic for a national scale predictor. The modelling exercise suggested that those catchments currently at risk of exceeding proposed suspended sediment yield critical thresholds are largely confined to upland areas across Wales and northwest England and the chalklands of southern and eastern England.  相似文献   

Modeling patterns of coral bleaching at a remote Central Pacific atoll     

Gareth J. Williams  Ingrid S. Knapp  Simon K. Davy 《Marine pollution bulletin》2010,60(9):1467-1476

A mild bleaching event (9.2% prevalence) at Palmyra Atoll occurred in response to the 2009 ENSO, when mean water temperature reached 29.8-30.1 °C. Prevalence among both abundant and sparse taxa varied with no clear pattern in susceptibility relating to coral morphology. Seven taxon-specific models showed that turbidity exacerbated while prior exposure to higher background temperatures alleviated bleaching, with these predictors explaining an average 16.3% and 11.5% variation in prevalence patterns, respectively. Positive associations occurred between bleaching prevalence and both immediate temperature during the bleaching event (average 8.4% variation explained) and increased sand cover (average 3.7%). Despite these associations, mean unexplained variation in prevalence equalled 59%. Lower bleaching prevalence in areas experiencing higher background temperatures suggests acclimation to temperature stress among several coral genera, while WWII modifications may still be impacting the reefs via shoreline sediment re-distribution and increased turbidity, exacerbating coral bleaching susceptibility during periods of high temperature stress.  相似文献   

Instability of coral limestone cliffs due to extreme waves     

Tetsuya Kogure  Yukinori Matsukura 《地球表面变化过程与地形》2010,35(11):1357-1367

Many boulders are located around the coastal cliffs with height of below 5 m made of coral limestone at Kuro‐shima, Okinawa, Japan. The origin of the boulders appears to be coral limestone cliffs which show developed notches. We undertook stability analysis, involving the wave pressure due to tsunamis, of wave‐induced collapse of the cliffs. We find that extreme waves are capable of inducing cliff collapse, as observed in circumstances where gravity is insufficient. Copyright © 2010 John Wiley and Sons, Ltd.  相似文献   

天然固定沙地与人工固沙植被区土壤种子库的比较研究     

崔艳  王新平  冯丽  苏延桂 《中国沙漠》2010,30(5):1114-1119

土壤种子库是退化生态系统植被恢复重建的重要基础,研究土壤种子库特征对于阐明退化生态系统受损与恢复机理具有重要的科学意义。通过野外土样采集、野外种子萌发定位跟踪调查和室内周期性种子萌发实验,对腾格里沙漠东南缘人工固沙植被区和天然固定沙地的土壤种子库特征进行了对比研究。结果表明：人工固沙植被区土壤种子库包含21个物种,分属于8科;天然固定沙地土壤种子库有33种植物,属于11科。人工固沙植被区以一年生植物为主,天然固定沙地以多年生植物为主。人工固沙植被区的种子总密度明显低于天然固定沙地,但不同物种种子的密度变化存在显著差异。人工固沙植被区的物种丰富度和多样性指数均较天然固定沙地低。人工固沙植被区和天然固定沙地的土壤种子库与地上植被物种的相似性系数分别为0.73和0.71。尽管人工固沙植被区土壤种子库存在少量多年生植物种子,但仍未发展到以多年生草本植物为主的群落演替阶段,说明人工固沙植被区的植物多样性恢复尚需要漫长的过程。  相似文献   

造礁珊瑚碳、氮、硼同位素的海洋酸化指示意义     

韩韬  余克服  陶士臣 《热带地理》2016,36(1):48-54

大气CO2体积分数升高导致的海洋酸化不仅会降低海水pH,还会改变其碳酸盐平衡体系,使得海水中文石饱和度（Ω）降低,相应地会降低珊瑚钙化的速率。已有研究表明：珊瑚骨骼δ13C、δ11B和δ15N具有记录Suess Effect、生物生产力、海水pH值以及营养源的能力;主要表现为：δ11B记录的pH值、δ13C记录的海水无机碳库（DIC）δ13C和生物生产力,以及δ15N记录的陆源物质输送量相结合,可用来指示受季风影响的南海“大陆架碳泵”和近海污染与海洋酸化的联系。目前关于珊瑚对海洋酸化的记录研究仍相对较少,珊瑚碳-氮-硼同位素组合的应用将会加深对于海洋酸化与气候变率和全球碳、氮循环的关系的认识,可能成为揭示海水pH值变化规律性的重要手段。  相似文献