SCUBA divers above the waterline: Using participatory mapping of coral reef conditions to inform reef management     

《Marine Policy》2017

Coral reefs provide important ecological services such as biodiversity, climate regulation, and cultural benefits through recreation and tourism. However, many of the world's reefs are declining, with Caribbean reefs suffering a significant decline in living corals over the past half century. This situation emphasizes the need to assess and monitor reef conditions using a variety of methods. In this study, a new method for assessing reef conditions to inform management using participatory mapping by coral reef “experts” in the U.S. Virgin Islands (USVI) is described. Occupational SCUBA divers were recruited (n=87) to map coral reef conditions, uses, and threats (stressors) using an internet-based mapping website. The data reveal an uneven geographic distribution of reef conditions in the USVI with the most frequently mapped perceived healthy reef characteristics being: large amount of physical reef structure (n=872 markers); endangered or threatened species present (n=721); and large amount of live coral cover (n=615). The greatest perceived threats were: invasive species (n=606); water pollution (n=234); and unsustainable fishing (n=200). Areas of important reef characteristics, perceived threats to reefs, and perceived recovery potential were plotted to identify areas requiring critical management attention. The authors found that perceptions of healthy reef conditions outnumbered perceptions of reef threats for nine of the ten most familiar coral reefs; the most frequent activity type within the coral reefs was tourism diving; and for the most familiar coral reefs, the divers perceived a high recovery potential. Given the novelty of participatory mapping methods to assess coral reefs, the strengths and weaknesses of the method is evaluated. The authors further propose a management typology for categorizing reef areas to inform their future management. In the absence of primary data, or, as a supplement to underwater surveys and remotely-sensed data on reef condition, participatory mapping can provide a cost-effective means for assessing coral reef conditions while identifying place-specific reef locations requiring management attention.  相似文献   

南海北部东沙群岛西部海域的海底沙波与内波的研究进展   总被引：2，自引：2，他引：0  

张洪运  庄丽华  阎军  马小川 《海洋科学》2017,41(10):149-157

南海北部外陆架和上陆坡分布着大量的各种类型的深水沙波,经过统计,这些沙波的活动性十分迥异,有着不同于浅水沙波的运移机制。基于国内外对该地区沙波研究成果的总结,指出天文潮、风暴潮等因素均不可能造成海底沙波的持续运动。南海北部同时是世界上内波活动最频繁的区域,与沙波活动区存在空间一致性。经过本文的综述分析,南海北部频发的内波可以造成海底的强流,是造成该海域海底沙波活动的主要原因,未来应在此框架理论下,进行相关证实研究。  相似文献   

Marine resource conservation and prospects for environmental sustainability in Anuta, Solomon Islands   总被引：1，自引：1，他引：0  

Richard Feinberg 《Singapore journal of tropical geography》2010,31(1):41-54

It has been argued that atolls have abundant, varied and dependable marine resources and that atoll-dwellers' exploitation of marine fauna has remained essentially constant since prehistoric times. According to that line of argument, modern technology, in and of itself, has had little effect on the relationship between human populations and the natural environment. A countervailing view contends that the market economy and reliance upon money have disrupted egalitarian socioeconomic systems and threatened the long-standing ecological balance. Here I consider questions of environmental sustainability and economic viability on Anuta, a Polynesian outlier in Solomon Islands. Anuta, a volcanic island, has more abundant terrestrial resources than do atolls, and all indications are that it has been a hierarchically-organized chiefdom for well over a dozen generations. Nonetheless, it is a small, seemingly vulnerable community. In reality, productivity of land and sea have remained stable at least since the 1970s, in part because of conscious, purposeful decisions intended to preserve the island's natural resources. Thus, Anutans can be described as conservationists in the technical sense used by some authors. Yet on Anuta, as elsewhere, a combination of population growth and market exchange has begun to place a strain on the environment and raises questions for their system's long-term viability.  相似文献   

Sustainable land use in Tikopia: Food production and consumption in an isolated agricultural system   总被引：3，自引：3，他引：0  

Ole Mertz  Thilde Bech Bruun  Bjarne Fog  Kjeld Rasmussen  Jytte Agergaard 《Singapore journal of tropical geography》2010,31(1):10-26

The land use system on Tikopia – a Polynesian outlier in Solomon Islands – is analyzed to determine how it has developed since it was first described in the 1930s and again in the 1970s. Fieldwork included a household questionnaire survey, in-depth interviews on farming practices and decision making, and the collection of soil samples from the major soil and garden types. The Tikopian land use system has not undergone significant changes since the 1970s; indeed the focus on self-sufficiency in food crops may have been strengthened over the past 30 years as ship arrivals have become increasingly unreliable. Local agricultural production and exploitation of marine resources are essential to sustain the population, and with few exceptions farming and fishing techniques remain unchanged. Most of the island is still farmed permanently and the intensive agricultural system has not suffered long-term setbacks, not even from extreme events such as Cyclone Zoe in 2002. The high fertility of Tikopian soils reported in the 1960s was found to be unchanged. It is concluded that the land use system is highly resilient to shocks and that there are no indications that Tikopian villagers would not be able to support their subsistence in the future, provided there is no substantial increase in the resident ( de facto ) population.  相似文献   

Demographic and environmental conditions are uncoupled in the social–ecological system of the Pribilof Islands     

Henry P. Huntington  Sarah A. Kruse  & Astrid J. Scholz 《Polar research》2009,28(1):119-128

Since the end of the commercial fur seal hunt in 1984, the economy of the Pribilof Islands, Alaska, has lacked a stable, lasting basis. As a contribution to the effort to understand and promote the effective management of the Pribilof Islands as a social–ecological system, we examined current and recent conditions on the islands to assess local perceptions of, and prospects for, economic, social and environmental well-being. We found few correlations between environmental conditions and socio-economic indicators. The lack of apparent connection between population levels and economic or environmental stimuli is likely attributable to one or more of several factors: (a) modest economic dependence on the environment; (b) predominance of other economic inputs to the economies of the islands; (c) islanders basing residence choices largely on non-economic factors; and (d) the islanders' tolerance for economic fluctuations and uncertainty. These results suggest economic analysis alone is insufficient to explain the dynamics of this social–ecological system, contrary to many other case studies and an expectation of tight coupling and clear connections between society and ecology in the Pribilofs.  相似文献   

千岛岛弧2006年Mw8.3地震前震源机制解的一致性变化   总被引：1，自引：0，他引：1  

泽仁志玛  刁桂苓  李志雄  王晓山  冯向东 《地震学报》2009,31(4)

地震是地下介质受到应力作用产生破裂的自然现象,分析强震震源区应力状态空间分布及其随时间的变化,对于了解和预测地震的形成过程具有重要意义.  相似文献   

Summertime sea surface temperature fronts associated with upwelling around the Taiwan Bank     

Kuo-Wei Lan  Hiroshi Kawamura  Ming-An Lee  Yi Chang  Jui-Wen Chan  Cheng-Hsin Liao 《Continental Shelf Research》2009

It is well known that upwelling of subsurface water is dominant around the Taiwan Bank (TB) and the Penghu (PH) Islands in the southern Taiwan Strait in summertime. Sea surface temperature (SST) frontal features and related phenomena around the TB upwelling and the PH upwelling were investigated using long-term AVHRR (1996–2005) and SeaWiFS (1998–2005) data received at the station of National Taiwan Ocean University. SST and chlorophyll-a (Chl-a) images with a spatial resolution of 0.01° were generated and used for the monthly SST and Chl-a maps. SST fronts were extracted from each SST images and gradient magnitudes (GMs); the orientations were derived for the SST fronts. Monthly maps of cold fronts where the cooler SSTs were over a shallower bottom were produced from the orientation.  相似文献   

权力、地缘环境与地缘位势评价——以中日钓鱼岛之争为例     

胡志丁  刘玉立  李灿松  葛岳静 《热带地理》2014,34(1):50-57

权力是国际政治的一个永恒话题,然而,国际关系学对权力的研究缺乏空间维度。考虑空间距离、地缘环境（由地理环境、地缘关系和地缘结构3部分组成）等对权力的空间制约,权力在空间的不均衡分布就是地缘位势。据此理解,文章从权力的4个来源,即军事实力、经济实力、软实力和不平等相互依赖,并结合地理衰减原理构建了地缘位势评价方法。以中日钓鱼岛之争为例,定量评价了中日两国在钓鱼岛的地缘位势,结果表明：随着中国崛起,整体经济实力、军事实力和中日之间不平等相互依赖关系的转变,至2010年中国在钓鱼岛的地缘位势已经全面超越日本。这一评价结果既可以回应国人在钓鱼岛问题上的不同声音,同时也阐释了自2012年以来中国在钓鱼岛问题上积极的处理方式。  相似文献   

南沙岛礁及周边港口可达性评价模型研究   总被引：2，自引：1，他引：1  

石伟  苏奋振  周成虎  吴文周 《地理学报》2014,69(10):1510-1520

中国的南沙群岛位于南海南部,岛礁星罗棋布,但受到岛礁自身面积及其他自然条件的限制,自持力和承载能力都较差,需要外界的持续补给才能维持大量人口的活动。南沙岛礁远离大陆,分布于被称为“危险地带”的珊瑚礁丛中,补给受到很大影响。目前,南沙群岛的岛礁部分被菲律宾、越南和马来西亚等国非法侵占,这些被其他国家非法控制的岛屿和沙洲的控制态势对其周边的海域产生一定的控制,并且将对通过的船舶产生较大的影响。针对南沙岛礁补给困难和控制态势复杂的现状,本文从南沙岛礁的自然条件和控制态势入手,提出了一种基于最小累积成本距离和加权Voronoi图的综合可达性指数,通过建立水深与航行成本的分级对应关系,构建了南沙岛礁及周边港口可达性评价模型,计算了南沙23个岛礁和周边国家9个重要港口之间的综合可达性指数,通过分析南沙主要岛礁和周边国家重要港口之间的综合可达性的优劣,可以为中国在南沙建设补给和中转基地选址提供决策参考。可以为中国开发和管理南沙群岛、制定海洋发展战略提供依据。  相似文献   

南沙暖水形成的动力和热动力过程的初步数值研究   总被引：1，自引：0，他引：1  

蔡树群  甘子钧  李志伟  龙小敏  董丹鹏 《海洋科学进展》2004,22(2):138-146

利用一个简化的上混合层垂直积分模式,对南海南部“南沙暖水”形成的动力和热动力过程进行数值研究。结果表明：(1)在春季,南沙暖水的形成主要来自海面净热通量的贡献,而通过热平流、苏禄海或巽它陆架以南的暖水进入的贡献甚小;(2)在冬季,南沙群岛海区流场强度增大,热平流项的贡献大于或等于海面净热通量的贡献,海温的降低幅度也较其他深海区的要大。但由于该海区在此前的季节中初始温度场较高,因而使得该海区的海温仍保持较高的水平;(3)南沙暖水的形成和维持高温的机制是随着季节的变化而变化的。  相似文献