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151.
研究滨海湿地围垦养殖后沉积物有机碳库的动态变化,对科学评估沿海滩涂湿地开发利用对碳库的影响具有重要意义.以闽江口鳝鱼滩湿地为研究区,采集不同围垦年限(3 a和15 a)养殖塘和短叶茳芏(Cyperus malaccensis)(养殖塘围垦前主要土著植被)湿地沉积物,测定其总有机碳(TOC)、有机碳组分(微生物生物量碳(MBC)、易氧化有机碳(EOC)、水溶性有机碳(WSOC))及有机碳矿化特征,并基于时空互代法,分析了围垦养殖对沉积物TOC、有机碳组分及矿化的影响.结果表明:围垦养殖3 a,沉积物TOC和WSOC含量总体上没有显著变化,但围垦15a,表层(0~10 cm)沉积物TOC和WSOC含量显著增加,其增加比例分别约为68.36%和68.01%;围垦养殖后,沉积物MBC没有显著变化,EOC含量则有所降低,围垦15 a后表层沉积物EOC含量约降低37.35%.围垦养殖后表层沉积物有机碳矿化速率和累积矿化量均高于短叶茳芏湿地,而亚表层(10~20 cm)沉积物矿化速率差异不显著,且表层累积矿化量高于亚表层.养殖塘沉积物TOC及有机碳组分受长期水淹和饵料添加等管理方式的影响,同时受黏粒、TN和TP等理化性质的间接影响,进一步影响沉积物矿化速率、累积矿化量和潜在矿化量(C0).上述结果预示着滨海湿地围垦养殖在一定程度上增加了沉积物有机碳的蓄积,同时也促进了有机碳矿化. 相似文献
152.
象山港网箱养殖对海域环境的影响及其养殖环境容量研究 总被引:9,自引:0,他引:9
以象山港海域的潮流模型和物质输运模型为基础,建立了各网箱养殖区的氮、磷污染物排放量与研究海域水质之间的响应关系,对该海域的养殖污染状况进行了模拟,讨论了该海域的网箱养殖环境容量.结果表明,象山港内的氮、磷浓度在养殖区密集的港顶海域超出一类水质标准;该海域的氮、磷养殖环境容量分别为670.74t/a和77.32t/a.目前,象山港内各网箱养殖区的污染物排放量已超出其容量,需进行削减. 相似文献
153.
154.
青虾是松嫩平原盐碱湿地重要的渔业生物资源 ,具有一定的渔业经济价值。以新荒泡为例 ,介绍了青虾的生物学特征、资源利用现状及其增殖途径 ,提出了青虾的池塘、稻田与网箱养殖的模式及其主要技术措施。 相似文献
155.
中国水产品质量安全与有机水产养殖探讨 总被引:6,自引:0,他引:6
随着中国水产养殖业的迅速发展。养殖水体环境污染、药物滥用等因素导致了常规水产品质量不断下降。有机水产养殖作为一种可持续发展模式。旨在实现水产健康安全养殖与生态环境保护的协调发展。是2l世纪中国水产健康养殖的发展方向和必然趋势。本文阐述了有机水产养殖的内涵和基本原则。探讨了中国有机水产养殖的兴起与发展现状。并就如何保证水产健康发展提出了若干建议。 相似文献
156.
SUMMARY Aquaculture has provided an alternative animal protein source for people for decades. The transfer of improved aquaculture technology has assisted economic growth in less developed countries by such donor countries as the USA, Japan, the European economic communities, Canada and Australia. Donor agencies provided funding for purchasing advanced equipment, professional training, professional consultation, and experts to advise recipient countries. The level of success varied for each project. The Oceanic Institute (OI) in Hawaii has engaged in aquaculture development in many regions for decades. The successful transfer of finfish fry production technology has been demonstrated recently in Indonesia and Egypt. Past experience provides a foundation for the next generation of technology transfer, involving consideration of socioeconomics. This paper examines the difficulties encountered in traditional technology transfer, and the need for sustainable aquaculture development in recipient countries. 相似文献
157.
池塘养殖生态系统空气调节服务价值的实证研究 总被引:4,自引:1,他引:3
生态服务价值的评估对于研究人员、政策制定者和公众都有重大意义,而农业生态系统价值往往集中于食物的供给价值,而生态系统的调控服务价值、支持服务价值和文化服务价值往往被忽略。空气调控服务属于生态系统调控服务中的一种,通过按季度检测池塘养殖水体的叶绿素a含量,计算养殖池塘的初级生产力,再以工业制氧法、碳税法和造林成本法估算了常规鱼类池塘养殖生态系统空气调节服务价值。结果表明:常规鱼类池塘养殖生态系统空气调节服务总价值为63 42248 yuan/a〖DK1〗·hm2。考虑到系统内部耗氧和向系统外释放含碳气体导致的价值损失,常规鱼类池塘养殖生态系统空气调节服务总净价值为28 88674 yuan/a〖DK1〗·hm2,其中固碳净价值为 25 46328 yuan/a〖DK1〗·hm2,释放氧气的净价值为3 42346 yuan/a〖DK1〗·hm2。相较44 0221 yuan/a〖DK1〗·hm2的池塘养殖水产品的市场价值,空气调节服务价值超过养殖水产品市场价值的一半以上,表明池塘养殖的生态服务价值对人类社会的贡献不可忽视。研究认为,由于池塘藻类的高增长率,常规水产池塘养殖系统空气调节服务价值高于一些种植业生态系统的空气调节服务价值。 相似文献
158.
Goal, Scope and Background Marine cage aquaculture produces a large amount of waste that is released directly into the environment. To effectively manage
the mariculture environment, it is important to determine the carrying capacity of an aquaculture area. In many Asian countries
trash fish is dominantly used in marine cage aquaculture, which contains more water than pellet feed. The traditional nutrient
loading analysis is for pellet feed not for trash fish feed. So, a more critical analysis is necessary in trash fish feed
culturing areas.
Methods Corresponding to FCR (feed conversion rate), dry feed conversion rate (DFCR) was used to analyze the nutrient loadings from
marine cage aquaculture where trash fish is used. Based on the hydrodynamic model and the mass transport model in Xiangshan
Harbor, the relationship between the water quality and the waste discharged from cage aquaculture has been determined. The
environmental carrying capacity of the aquaculture sea area was calculated by applying the models noted above.
Results Nitrogen and phosphorus are the water quality parameters considered in this study. The simulated results show that the maximum
nitrogen and phosphorus concentrations were 0.216 mg/L and 0.039 mg/L, respectively. In most of the sea area, the nutrient
concentrations were higher than the water quality standard. The calculated environmental carrying capacity of nitrogen and
phosphorus in Xiangshan Harbor were 1,107.37 t/yr and 134.35 t/yr, respectively. The waste generated from cage culturing in
2000 has already exceeded the environmental carrying capacity.
Discussion Unconsumed feed has been identified as the most important origin of all pollutants in cage culturing systems. It suggests
the importance of increasing the feed utilization and improving the feed composition on the basis of nutrient requirement.
For the sustainable development of the aquaculture industry, it is an effective management measure to keep the stocking density
and pollution loadings below the environmental carrying capacity.
Conclusions The DFCR-based nutrient loadings analysis indicates, in trash fish feed culturing areas, that it is more critical and has
been proved to be a valuable loading calculation method. The modeling approach for Xiangshan Harbor presented in this paper
is a cost-effective method for assessing the environmental impact and determining the capacity. Carrying capacity information
can give scientific suggestions for the sustainable management of aquaculture environments.
Recommendations and Perspectives It has been proved that numerical models were convenient tools to predict the environmental carrying capacity. The development
of models coupled with dynamic and aquaculture ecology is a requirement of further research. Such models can also be useful
in monitoring the ecological impacts caused by mariculture activities.
ESS-Submission Editor: Hailong Wang (hailong.wang@ensisjv.com) 相似文献
159.
长三角地区池塘养殖水产品体内农药类污染与食用风险评价 总被引:4,自引:0,他引:4
为了解池塘养殖水产品体内的农药污染情况,以便为水产品质量评价及保障当地居民的饮食健康提供科学依据,本研究采用气相色谱质谱联用法(GC-MS)对长三角地区13个养殖池塘中5类(蟹类、鳖类、蚌类、虾类、鱼类)水产品体内9种有机磷农药(OPPs)、8种有机氯农药(OCPs)以及4种拟除虫菊酯类农药(SPs)进行了检测,并初步分析了其污染来源。结果表明,水产品体内3类农药均有检出,但残留水平均不高,OPPs残留总量为未检出至299 ng·g-1(dw),三唑磷、伏杀硫磷、喹硫磷和毒死蜱较易在水产品体内蓄积;OCPs残留总量为16~82 ng·g-1(dw),主要污染物为六六六(HCHs),主要来自历史残留;SPs残留总量为44~89 ng·g-1(dw),主要污染物为高效氯氟氰菊酯。水产品体内的农药污染可能与养殖池塘中的沉积物污染密切相关。5类水产品体内3类农药的总风险指数(HI)为0.0020~0.046,远小于1,因此,长三角地区由3类农药造成的健康风险处于安全水平。 相似文献
160.
Finding aquaculture development approaches to open up livelihood opportunities for the rural poor and in mainstreaming smallholder fish farmers to reduce poverty remain a challenge. This paper examines the community-based technology transfer mechanism of mudcrab nursery in ponds and its socioeconomic impacts on smallholder mudcrab growers in Northern Samar, Philippines. Results indicated that the technology is a viable enterprise done by a straight culture system method, which is the rearing of crablets from <1.0 to 4.0 cm for 42 days, or by-phases. However, technology adoption hinges on many factors like area ownership, farm distance from household, and market including the type of strategy needed to enhance technology uptake. Collaboration among research and development institutions and local partners is critical in training and empowering rural communities to adopt aquaculture technologies.