波浪能海水淡化的应用研究

简要介绍了“十五”期问在广东省汕尾市研建的波浪能海水淡化系统的组成和工作原理。为了验证波浪能海水淡化装置运行的实用性和可靠性，在国内外波浪能海水淡化研究的基础上，对汕尾波浪能海水淡化装置进行了不同操作压力情况下的试验研究。研究结果表明，随着高压海水压力的升高，产出淡水量会明显增加，淡水质量提高，装置产出淡水的能耗较低。

A long-term study (1949-2005) of experimental introductions to an island; freshwater amphipods (Crustacea) in the Isle of Man (British Isles)

Using data from field introduction experiments with Gammarus spp. conducted in the rivers of a small island, commencing in 1949, with resampling in the 60s, 70s, 80s, 90s and finally in 2005, we aimed to examine the long-term interaction of the native freshwater amphipod Gammarus duebeni celticus with the introduced G. pulex. Using physico-chemical data from a 2005 island-wide survey, we also aimed to find what environmental factors could influence the distribution of the two species.

The life, adventures, and pyracies, of the famous Captain Singleton: containing an account of his being set on shore in the island of Madagascar, his settlement there, with a description of the place and inhabitants... As also Captain Singleton's return to sea, with an account of his many adventures and pyracies with the famous Captain Avery and others.

Photocopy.

Narrative of a voyage, in His Majesty's late ship Alceste, to the Yellow Sea : along the coast of Corea, and through its numerous hitherto undiscovered islands to the island of Lewchew, with an account of a shipwreck in the Straits of Gaspar /

Shaw & Shoemaker

Barrier Island Response to Sea Level Rise in North Carolina

The state of North Carolina is home to some of the most spectacular barrier islands in the world. These features are constantly shifting, impacted by waves, tides, and wind. Studies of the Outer Banks, North Carolina have resulted in varied results, but a detailed analysis of the barrier system as a whole is lacking. Using historic topographic surveys (T-sheets) from the 19th, the positions of various barrier segments were analyzed in relation to modern imagery. Changes in area, width, and center line locations were evaluated over the past 150 years. In total, 74 percent of modern transects have decreased in area. Total reductions in size were 130 km2 for the study period. Mean centerlines as a function of migration showed that 53 percent of segments were demonstrating directional movement away from the ocean. The average movement towards the bay between modern and historic centerlines was 8 meters. Thusly, barrier islands in North Carolina are demonstrating both decreases in total area and directional movement inland in response to sea level rise.

High density mangrove plantation enhances surface accretion, surface elevation change, and tree survival in coastal areas susceptible to sea-level rise

Survival, growth, above ground biomass accumulation, soil surface elevation dynamics and nitrogen accumulation in accreted sediments were studied in experimental treatments planted with four different densities (6.96, 3.26, 1.93 and 0.95 seedlings m-2) of the mangrove Rhizophora mucronata in Puttalam Lagoon, Sri Lanka. Measurements were taken over a period of 1171 days and were compared with those from unplanted controls. Trees at the lowest density showed significantly reduced survival, whilst measures of individual tree growth did not differ significantly among treatments. Rates of surface sediment accretion (means ± S.E.) were 13.0 (±1.3), 10.5 (±0.9), 8.4 (±0.3), 6.9 (±0.5) and 5.7 (±0.3) mm yr-1 at planting densities of 6.96, 3.26, 1.93, 0.95, and 0 (unplanted control) seedlings m-2, respectively, showing highly significant differences among treatments. Mean (± S.E.) rates of surface elevation change were much lower than rates of accretion at 2.8 (±0.2), 1.6 (±0.1), 1.1 (±0.2), 0.6 (±0.2) and -0.3 (±0.1) mm yr-1 for 6.96, 3.26, 1.93, 0.95, and 0 seedlings m-2, respectively. All planted treatments appeared to accumulate greater nitrogen concentrations in the sediment compared to the unplanted control, and suggests one potential causal mechanism for the facilitatory effects observed; high densities of plants potentially contribute to the accretion of greater amounts of nutrient rich sediment. While this potential process needs further study, this study demonstrated how higher densities of mangroves enhance rates of sediment accretion and surface elevation, processes that may be crucial in mangrove ecosystem adaptation to sea level rise. There was no evidence that increasing plant density evoked a trade-off with growth and survival of the planted trees. Rather facilitatory effects enhanced survival at high densities, suggesting that local land managers may be able to take advantage of plantation densities to help mitigate sea-level rise effects by encouraging positive soil surface elevation increment, and perhaps even greater nutrient retention to promote mangrove growth and ameliorate nearshore eutrophication in tropical island environments.

Abrupt changes in high-latitude nutrient supply to the Atlantic during the last glacial cycle

The supply of nutrients to the low-latitude thermocline is largely controlled by intermediate-depth waters formed at the surface in the high southern latitudes. Silicic acid is an essential macronutrient for diatoms, which are responsible for a significant portion of marine carbon export production. Changes in ocean circulation, such as those observed during the last deglaciation, would influence the nutrient composition of the thermocline and, therefore, the relative abundance of diatoms in the low latitudes. Here we present the first record of the silicic acid content of the Atlantic over the last glacial cycle. Our results show that at intermediate depths of the South Atlantic, the silicic acid concentration was the same at the Last Glacial Maximum (LGM) as it is today, overprinted by high silicic acid pulses that coincided with abrupt changes in ocean and atmospheric circulation during Heinrich Stadials and the Younger Dryas. We suggest these pulses were caused by changes in intermediate water formation resulting from shifts in the subpolar hydrological cycle, with fundamental implications for the nutrient supply to the Atlantic.

Single beam survey data and links to sea-bottom video files off Helgoland

Kelp forests represent a major habitat type in coastal waters worldwide and their structure and distribution is predicted to change due to global warming. Despite their ecological and economical importance, there is still a lack of reliable spatial information on their abundance and distribution. In recent years, various hydroacoustic mapping techniques for sublittoral environments evolved. However, in turbid coastal waters, such as off the island of Helgoland (Germany, North Sea), the kelp vegetation is present in shallow water depths normally excluded from hydroacoustic surveys. In this study, single beam survey data consisting of the two seafloor parameters roughness and hardness were obtained with RoxAnn from water depth between 2 and 18 m. Our primary aim was to reliably detect the kelp forest habitat with different densities and distinguish it from other vegetated zones. Five habitat classes were identified using underwater-video and were applied for classification of acoustic signatures. Subsequently, spatial prediction maps were produced via two classification approaches: Linear discriminant analysis (LDA) and manual classification routine (MC). LDA was able to distinguish dense kelp forest from other habitats (i.e. mixed seaweed vegetation, sand, and barren bedrock), but no variances in kelp density. In contrast, MC also provided information on medium dense kelp distribution which is characterized by intermediate roughness and hardness values evoked by reduced kelp abundances. The prediction maps reach accordance levels of 62% (LDA) and 68% (MC). The presence of vegetation (kelp and mixed seaweed vegetation) was determined with higher prediction abilities of 75% (LDA) and 76% (MC). Since the different habitat classes reveal acoustic signatures that strongly overlap, the manual classification method was more appropriate for separating different kelp forest densities and low-lying vegetation. It became evident that the occurrence of kelp in this area is not simply linked to water depth. Moreover, this study shows that the two seafloor parameters collected with RoxAnn are suitable indicators for the discrimination of different densely vegetated seafloor habitats in shallow environments.