共查询到20条相似文献，搜索用时 843 毫秒
1.
2.
《中国海洋工程》2005,19(4):F0003-F0003
China Ocean Engineering takes as its prime function the integration of new research concepts, equipment, technology, materials and structures and other scientific advances within the field of ocean engineering, with particular reference to developments in China. Tne Journal is concerned with all engineering aspects involved in the exploration and utilization of ocean resources, such as offshore engineering, coastal engineering, dive and salvage, utilization of marine energy, resourees and underwater engineering. 相似文献
3.
4.
5.
6.
7.
8.
9.
《中国海洋工程》2007,21(2):F0003-F0003
China Ocean Engineering takes as its prime function the integration of new research concepts, equipment, technology, materials and structures and other scientific advances within the field of ocean engineering, with particular reference to developments in China. The Journal is concerned with all engineering aspects involved in the exploration and utilization of ocean resources, such as offshore engineering, coastal engineering, dive and salvage, utilization of marine energy resources and underwater engineering.[第一段] 相似文献
10.
11.
12.
《中国海洋工程》2014,(2):F0003-F0003
正Being an international journal,China Ocean Engineering takes as its prime function the integration of new research concepts,equipment,technology,materials and structures and other scientific advances within the field of estuarial,coastal,offshore,and deepwater engineering with particular reference to developments.The Journal is concerned with all engineering aspects involved in the exploration and utilization of ocean resources.Topics regularly covered include research,design and 相似文献
13.
14.
15.
Mantha Gopikrishn Al-Sofyani Abdulmohsin A. Ali M Al-Aidaroos Crosby Michael P 《海洋学报(英文版)》2019,38(12):59-72
Zooplankton and zooneuston observations were made at seven stations(four from the Gulf of Aqaba and three from the northern Red Sea), during September and October 2016. The main objective of this study was to assess the variability of nycthemeral fauna in relation to the sampling methods using two different types of nets namely,WP2 net and Neuston net along the two study sites, i.e., the Gulf of Aqaba and the northern Red Sea. Zooplankton was sampled vertically using a standard WP2 net from a depth of 200 m to the surface, whereas zooneuston was made using a standard Neuston net from a depth of 0–10 cm of the water surface. Total zooplankton density was maximum during night time((617.83 ± 201.84) ind./m~3) at the Gulf of Aqaba and total zooneuston was maximum during night at the northern Red Sea((60.94±29.48) ind./m~3), respectively. The most abundant taxa were Copepoda, Gastropoda, Bivalva, Chaetognatha, Tunicata and Ostracoda. The abundance was almost 50% higher at night time at both the Gulf of Aqaba and the northern Red Sea. Overall, 30 taxa covering 10 phyla and 27 taxa covering 8 phyla were recorded in the Gulf of Aqaba and the northern Red Sea. 相似文献
16.
《African Journal of Marine Science》2013,35(1):773-789
There are two types of interactions between seals and commercial fisheries in South Africa: biological (potential competition for shared resources between the two "predators") and operational (conflicts during fishing operations). Using data for the 1980s, a comparison is made of relative consumption by different predators in South African waters. Seals and fisheries are not the major consumers in the system, but they do take comparable amounts. This has resulted in calls for a reduction in the seal population, but to date, no studies have shown that reducing seal predation of commercial species will make more fish available for the fisheries. Most fisheries are subject to some form of operational interaction with seals. These interactions include consumption of catches (operational consumption), disturbance of fishing operations (operational disturbance) and damage to fishing gear (operational gear damage); they vary in degree of severity, both seasonally and regionally. Estimates of the consumption by seals from fishing operations in South Africa show it to be a minimal percentage of fishery catches and a small proportion of the total predation by seals. Preliminary calculations of overall economic losses resulting from seal interference show this to be small in comparison with the wholesale value of the catches. Seals die as a result of fishing operations, and estimates of the potential mortality through entanglement, drowning and deliberate killing indicate this mortality to be of a magnitude that should be monitored. 相似文献
17.
《Marine Policy》2014
Tropical fisheries are in decline around world as a result of diverse anthropogenic threats. These threats are intimately linked to biodiversity and conservation values because of the heavy dependence of both fisheries and high value marine and coastal wetlands on coastal ecosystem health. Consequently, if the widespread degradation of coastal ecosystems can be halted and remediated, there are substantial benefits to fisheries output, ecosystem resilience, food security, livelihoods, recreation and the protection of ecological assets of national and global significance. The extent, intactness and quality of Australia׳s tropical coastal ecosystems has declined markedly since European settlement, due to the cumulative impact of many small encroachments and local barrier construction on the extent and productivity of coastal wetlands, mangroves and seagrass meadows. Additionally, coastal ecosystem dependent biota has been excluded from large areas of critical habitats. Despite these changes, coastal fisheries show no clear declines that could not be explained by changes in effort. This lack of detectable decline is probably partly attributable to the short history of available fisheries catch data. However, it is also likely that it reflects the offsetting of lost natural productivity by greatly increased anthropogenic nutrient loads; a substantial problem as governments are committed to large scale, long term efforts to reduce discharges of nutrients to coastal waters. This possibility underlines the importance of rejuvenating lost coastal productivity. Evaluation of past remediation efforts show that documented success is rare, due to a complex of factors including ineffective prioritisation, a lack of necessary knowledge and resources, and inefficient monitoring and evaluation. Past experiences from Australia׳s tropics and around the world, together with current ecological understanding, suggests some generally desirable characteristics to enhance the likelihood of successful remediation and repair actions. 相似文献
18.
How coral reefs with high productivity and biodiversity can flourish in oligotrophic tropical oceans has inspired substantial research on coral reef ecosystems. Increasing evidence shows that similar to water in an oasis in the desert, there are stable nutrient supplies to coral reefs in oligotrophic oceans. Here, with emphasis on the fluxes of organic matter, we summarize at the ecosystem level(1) the multiple input pathways of external nutrients,(2) the storage of nutrients in reef organisms,(... 相似文献
19.
Carbon and nitrogen isotopes have been widely used in the investigation of trophic relations, energy pathways, trophic levels and migrations, under the assumption that δ13C is independent of body size and that variation in δ15N occurs exclusively due to ontogenetic changes in diet and not body size increase per se. However, several studies have shown that these assumptions are uncertain. Data from food-webs containing an important number of species lack theoretical support on these assumptions because very few species have been tested for δ13C and δ15N variation in captivity. However, if sampling comprises a wide range of body sizes from various species, the variation of δ13C and δ15N with body size can be investigated. While correlation between body size and δ13C and δ15N can be due to ontogenetic diet shifts, stability in such values throughout the size spectrum can be considered an indication that δ13C and δ15N in muscle tissues of such species is independent of body size within that size range, and thus the basic assumptions can be applied in the interpretation of such food webs. The present study investigated the variation in muscle δ13C and δ15N with body size and body mass of coastal fishes and cephalopods. It was concluded that muscle δ13C and δ15N did not vary with body size or mass for all bony fishes with only one exception, the dragonet Callionymus lyra. Muscle δ13C and δ15N also did not vary with body size or mass in cartilaginous fishes and cephalopods, meaning that body size/mass per se have no effect on δ13C or δ15N, for most species analysed and within the size ranges sampled. The assumption that δ13C is independent of body size and that variation in δ15N is not affected by body size increase per se was upheld for most organisms and can be applied to the coastal food web studied taking into account that C. lyra is an exception. 相似文献
20.
Through introducing amidoxime and carboxyl groups into polyacrylonitrile fiber, a fibrous adsorbent with high capacity and fast adsorption rate was obtained, which could adsorb 4.6 mg uranium/g in 10 days from natural seawater. The influence of the functional group content on equilibrium adsorption capacity Xm and adsorption rate constant K of the adsorbent was studied, thus indicating that the contents of amidoxime and carboxyl groups correlated with Xm and K respectively. It is concluded that the amidoxime group is of reactive adsorption, while the carboxyl group is of promotion in the adsorption of uranium. In this paper, the mechanism of uranium adsorption on the fibrous adsorbent is deduced and the chelating structure of adsorption species is discussed with molecule orbit theory. 相似文献