Coral reefs under rapid climate change and ocean acidification

Atmospheric carbon dioxide concentration is expected to exceed 500 parts per million and global temperatures to rise by at least 2 degrees C by 2050 to 2100, values that significantly exceed those of at least the past 420,000 years during which most extant marine organisms evolved. Under conditions expected in the 21st century, global warming and ocean acidification will compromise carbonate accretion, with corals becoming increasingly rare on reef systems. The result will be less diverse reef communities and carbonate reef structures that fail to be maintained. Climate change also exacerbates local stresses from declining water quality and overexploitation of key species, driving reefs increasingly toward the tipping point for functional collapse. This review presents future scenarios for coral reefs that predict increasingly serious consequences for reef-associated fisheries, tourism, coastal protection, and people. As the International Year of the Reef 2008 begins, scaled-up management intervention and decisive action on global emissions are required if the loss of coral-dominated ecosystems is to be avoided.     

Pleistocene sea levels from raised coral reefs of haiti

The elevations and ages of a sequence of three uplifted Pleistocene coral reefs on the Northwest Peninsula of Haiti have been determined. With the assignment of a sea level of +6 meters (relative to the present day) at 130,000 years before present and constant uplift of the reefs, the data indicate that sea level stood -10 and -13 meters at 108,000 and 81,000 years before present, respectively. These results are in substantial agreement with those reported for Barbados and New Guinea and support the hypothesis of constant uplift for each area. Sea level data from raised reefs indicate that the interglacial marine oxygen isotope oscillations during oxygen isotope stage 5 are a result of 30 percent ice volume effects and 70 percent temperature effects.     

Sibling Species in Montastraea annularis, Coral Bleaching, and the Coral Climate Record

Measures of growth and skeletal isotopic ratios in the Caribbean coral Montastraea annularis are fundamental to many studies of paleoceanography, environmental degradation, and global climate change. This taxon is shown to consist of at least three sibling species in shallow waters. The two most commonly studied of these show highly significant differences in growth rate and oxygen isotopic ratios, parameters routinely used to estimate past climatic conditions; unusual coloration in the third may have confused research on coral bleaching. Interpretation or comparison of past and current studies can be jeopardized by ignoring these species boundaries.     

全域旅游视角下的资阳市旅游资源点空间结构研究

根据四川省最新的旅游分类标准和文旅普查结果,运用最近邻指数和不均衡指数从整体角度分析不同旅游资源类型的离散情况以及在各乡镇的分布均衡情况;利用地理信息技术(GIS)和相关技术软件对旅游资源点进行核密度分析、缓冲区分析和交通可达性分析,从空间上更直观地表示出资源点的聚集情况和地理位置分布情况,以及旅游发展所必需的交通状况...     

基于文化视角的闽台旅游合作研究

闽台旅游合作是建设海峡西岸经济区发展战略的重要组成部分,随着闽台文化一体化研究的不断深入,必将在深度与广度上推进两岸在旅游、文化交流方面的发展。本文透过文化的视角,对闽台之间的历史渊源、民情风俗、宗教信仰、土语方言等诸方面进行论证,证实了闽台文化的独特性与一体性,并在此基础上对闽台旅游合作的文化基础、文化发展思路等提出见解、阐述、分析,对闽台旅游合作中旅游与文化的共同和谐发展提出了对策。将文化因素引入闽台旅游合作研究,将有利于巩固两岸文化同源的文化积淀,加深两岸人民的文化认同感,为今后长远和谐的发展提供稳固的合作保障。     

Mg/Ca Thermometry in Coral Skeletons

The magnesium-to-calcium (Mg/Ca) ratio of coral skeletons from Ishigaki Island, Ryukyu Islands, Japan, closely tracked sea surface temperature (SST) over an 8-year period. Measurements were made with the fast technique of inductively coupled plasma-atomic emission spectrometry. The variation of the coral Mg/Ca ratio with SST change is about four times that of the current, widely used coral strontium-to-calcium ratio. The temporal and geographic variation of the seawater Mg2+/Ca2+ ratio probably has little influence on coral Mg/Ca variation. Results indicate that the coral Mg/Ca ratio has the potential to provide fast, precise, high-resolution proxies for past tropical SSTs.     

Diversity in tropical rain forests and coral reefs

The commonly observed high diversity of trees in tropical rain forests and corals on tropical reefs is a nonequilibrium state which, if not disturbed further, will progress toward a low-diversity equilibrium community. This may not happen if gradual changes in climate favor different species. If equilibrium is reached, a lesser degree of diversity may be sustained by niche diversification or by a compensatory mortality that favors inferior competitors. However, tropical forests and reefs are subject to severe disturbances often enough that equilibrium may never be attained.     

Paleoceanography of coral reefs in the hawaiian-emperor chain

The fossil record of shallow marine organisms in the Hawaiian Archipelago and Emperor seamount chain indicates that reef corals were absent during the first half of the Tertiary. Their appearance during the early Oligocene, 34 million years ago, is associated with several paleoceanographic events that appear to have combined to intensify gradually gyral surface currents in the north Pacific. This association suggests that corals were absent in the early Tertiary because of isolation of the Hawaiian Archipelago from the Indo-West Pacific (IWP), the center of reef coral abundance and diversity in the Pacific. Today, the number of species of reef corals in Hawaii is less than 10 percent of the number of species in the IWP. Since their initial colonization, reef corals have been present continuously in the Hawaiian Archipelago, although not without taxonomic change. Episodes of extinction and recolonization are the most likely cause of change in species composition. Recolonization from the IWP may also explain the low rate of endemism (about 20 percent) in the present-day coral fauna.