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胶莱运河简史 元朝,从元世祖至元17年(1280年)曾利用胶州湾(胶澳)修筑胶莱运河,目的是南粮北运,缩短了里程,并且避开山东成山头恶烈的海况,繁荣了山东东部的经济。当时胶莱运河南起灵山湾,通过马浩沟黄岛西侧进入胶州湾,然后由大沽河至平度县的南村镇,引平度的沙河与沽河合流,入胶莱运河,南村镇为胶莱运河的分水岭。胶州湾的最大高潮位达到南村镇(距胶州湾约30km)。 相似文献
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国务院于2003年5月发布实施的《全国海洋经济发展规划纲要》,根据自然与资源条件、经济发展水平和行政区划关系,对我国海岸带及邻近海域划分为11个综合经济区,其中把以大连市为中心的辽东半岛海洋经济区列于首位,并且指明了今后发展的主要价值取向。毫无疑问,发挥海洋经济是大连城市发挥比较优势、实现经济可持续增长的必然选择。然而,必须看到,大连海洋经济的发展现状却是粗放型的、低层次的,这与国家“经略海洋”的战略要求相差甚远。而从自身的情况来看,如果停留在相对落后的海洋经济发展现状,将会使大连城市经济逐渐丧失其比较优势,束缚… 相似文献
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跨过入世门槛，中国海洋水产业面对更多的发展机会和空间。中国海洋水产行业应加强体制转型和结构调整，以应对入世后生产国际化和贸易自由化所带来的冲击，提高海洋水产业的总体竞争能力，扩大中国海洋水产品在国际市场的占有份额则成为当务之急。一、我国海洋水产业在国际市场的优势我国是世界水产大国，水产品总产量已连续１０年居世界第一位。我国也是世界上惟一水产养殖产量超过捕捞产量的国家。我国的水产品出口贸易世界排名第四位。这些造就了中国海洋水产业在国际市场的优势。第一，国际市场对水产品需求量逐年上升。我国是世界第一… 相似文献
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黄山市是世界著名的旅游胜地,风光优美,生态环境优越,矿泉水资源丰富,矿泉水产业发展条件有利。在对黄山市矿泉水产业发展现状进行调查分析的基础上,提出了黄山市矿泉水产业发展的对策和建议。 相似文献
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21世纪是人类全面认识、开发利用和保护海洋的新世纪。党和国家领导人对海洋事业非常重视,江泽民同志先后做出“振兴海业、繁荣经济”、“开发蓝色国土”的题词,要求我们“一定要从战略的高度,增强全民族的海洋意识”。我国是一个海洋大国,海洋对国民经济的贡献日益显著。广西是我国西部12个省区市中唯一具有临海资源综合优势的自治 相似文献
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水资源是社会经济可持续发展的决定性因素.在我国西北地区由于缺水,沙枣林大面积枯死,灌木林严重衰败,植被减少;沙漠化、盐碱化不断扩大,绿洲逐渐被吞噬.可见,水资源是生态环境中最敏感的环境因子. 相似文献
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April to October, 1997 comparative studios on the nitrogen budgets of closed shrimp polyculture systems showed that, in all the studied polyculture systems, nitrogen from feeds and fertilizers were the main input items, which comprised 70.7% - 83.9% of the total input nitrogen, 3.2% - 7.4% of which was provided by nitrogen fixation. It was in monoculture enclosures (Y-4, Y-11 and Y-12) that the percentage reached the maximum value. The output nitrogen in harvested products comprised 10.8% - 24.6% of total input nitrogen, and the highest percentage, 24.6%, was found in shrimp-fish-tagelus polyculture systems. In shrimp monoculture and shrimp-fish polyculture systems, they were 19.1% and 21.9%, respectively. The nitrogen utilization efficiency was different and varied from 12.2% to 20.1%. The highest, 20.1%, was found in shrimp-fish-tagelus polycultttre systems, and the average of 20.0% was found in shrimp-tagelus polyculture systems. The lowest, 12.2%, was found in shrimp monoculture systems.All the nitrogen utilization efficiencies in shrimp-fish systems or shrimp-scallop systems seemed to be higher than that of the monoculture system, but they showed little statistical difference. The main outputs of nitrngen were found in sediment mud, and comprised 48.2% -60.8% of the total input, the lowest percentage was found in shrimp-fish-tagelus polyculture systems, and the highost percentage in shrimp-scallop systems.During the experiment, nitrogen lost through denitrification and ammonia volatilization comprised 1.9% - 6.2%, averaged 2.8%, of the total input, and the loss through seepage comprised 5.9% - 8.9% of the total.The estimated nitrogen attached to the enclosure wall comprised 3.7% - 13.3% of the total, and was highest in shrimp monoculture systems. Compared with the classic shrimp farming industry, the closed shrimp polycul-ture systems may improve the nitrogen utilization efficiency, and hence reduce the environmental impacts on coastal waters. The nitrogen discharging rates for all the studied polyculture systems ranged from 3.0% to 6.0% of total input nitrogen. 相似文献
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Nwafili Sylvanus A. GAO TianXiang 《中国海洋大学学报(英文版)》2007,6(3):281-291
The changes that have taken place in Nigerian fisheries are reviewed. Artisanal fishery has continued to dominate the fisheries,contributing over 85% of total fish production. The inland water and coastal seas are fully exploited and the increase in fishery production is not likely. Aquaculture potentials remain untapped as much as deep-sea fisheries. The combined potential of the fisheries resources-freshwater,marine and aquaculture can meet over 90% of the nation's demand for fish. Opportunities for invest-ments,therefore,exist in the various subsectors,especially in the areas of storage,processing and preservation for the capture fishery and fish seed multiplication for aquaculture. 相似文献