首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
This study investigated monthly changes of sedimentation and sediment properties in three different culture systems (ponds) – i.e. jellyfish Rhopilema esculenta monoculture (J), sea cucumber Apostichopus japonicus and jellyfish co‐culture (SJ) and sea cucumber monoculture (S) – to verify the feasibility of co‐culturing jellyfish and sea cucumbers. Results showed that jellyfish culture accelerated the settling velocity of total particulate matter (TPM). Average TPM settling velocities in the SJ (75.6 g m?2 day?1) and J (71.1 g m?2 day?1) ponds were significantly higher than that in the S pond (21.7 g m?2 day?1) from June to September during the jellyfish culture period. Average settling velocities of organic matter (OM), total organic carbon (TOC), total nitrogen (TN) and total phosphorus (TP) in the SJ pond increased significantly by 3.0, 2.9, 3.3 and 3.8 times, respectively, compared with those in the S pond. Sediment contents of OM, TOC, TN and TP in the SJ and J ponds were significantly higher than those in the S pond during the jellyfish culture season. The specific growth rate of sea cucumbers feeding on SJ sediment was significantly higher than that of those feeding on S sediment. Co‐culturing sea cucumbers with jellyfish may help alleviate benthic nutrient loading due to the jellyfish and provide a secondary cash crop.  相似文献   

2.
2017、2018年连续2年利用7口0.4 hm~2(6亩)对虾养殖池在淡水条件下进行了鲻鱼与南美白对虾混养试验。试验结果:鲻鱼放养规格48~80 g/尾,放养密度为75~225尾/hm~2,收获鲻鱼规格为420~520 g/尾。2017年,南美白对虾单养池(对照池)产量为6 090 kg/hm~2,6口鱼虾混养池产量分别比对虾单养池高540~1 590 kg/hm~2,平均单产提高1 012.5 kg/hm~2;2018年对虾单养池产量5 790 kg/hm~2,6口混养池南美白对虾产量分别比对虾单养池高795~1 515 kg/hm~2,平均单产提高1 170 kg/hm~2。2017年6口鱼虾混养池养殖收益分别比对虾单养池高50 100~64 500元/hm~2,平均收益提高65 145元/hm~2;2018年6口鱼虾混养池的养殖收益分别比对虾单养池高28 500~55 950元/hm~2,平均收益提高40 365元/hm~2。池塘水质方面,养殖中后期,鱼虾混养池的氨氮、亚硝酸氮等水质指标明显低于对虾单养池。试验结果表明,选择合适的鱼类品种混养在对虾池中,对于改善池塘水质,增加养殖收益具有显著效果。  相似文献   

3.
为分析辽东湾海水生态养殖池塘仿刺参的食性特征,分别于2016年3月、5月、7月、9月、12月采集池塘中的浮游植物、浮游动物、颗粒有机物、底栖硅藻、表层底泥和仿刺参,并检测所有样品的δ13C和δ15N值。运用IsoSource线性混合模型计算出浮游植物、浮游动物、颗粒有机物、底栖硅藻、表层底泥对仿刺参的饵料贡献率。试验结果显示,底栖硅藻对仿刺参的平均饵料贡献率周年变化为78.5%~85.7%,颗粒有机物、浮游植物、浮游动物和表层底泥对仿刺参的贡献率分别为2.1%~5.1%、2.2%~5.6%、2.3%~7.7%、3.6%~7.9%。底栖硅藻对消化管内含物δ13C值的贡献率为25.8%~74.5%、颗粒有机物、浮游植物、浮游动物和表层底泥对消化管内含物δ13C值的贡献率分别为3.9%~15.3%、4.0%~18.3%、4.2%~19.4%、5.6%~22.2%。试验结果表明,在不投饵、缺乏底栖大型藻类的生态养殖池塘中,底栖硅藻是仿刺参主要的食物来源,仿刺参也摄食表层底泥、沉降后颗粒有机物和浮游动植物。研究结果可为海水池塘仿刺参的生态健康养殖提供基础数据。  相似文献   

4.
衡水湖国家级自然保护区是华北平原第二大淡水湿地,在生物多样性保护方面具有十分重要的价值。以衡水湖国家级自然保护区为例,结合其自身特点,参考湿地型自然保护区生态补偿计算方法,综合运用费用分析法、机会成本法、生态价值法及居民意愿法,确定衡水湖国家级自然保护区生态补偿的标准。结果表明,费用分析法得到衡水湖国家级自然保护区直接成本为10.39亿元/a;机会成本法得到其机会成本为6.55亿元/a;生态价值法得到其生态系统服务总价值为71.80亿元/a;居民意愿法得到其自然保护区退田还湖农户平均受偿意愿为4.5万元/(hm2·a);湖区农民户平均受偿意愿为5.4万元/(hm2·a),湖区渔民户平均受偿意愿为3.45万元/(hm2·a)。以自然保护区管理投入的直接成本价值和限制产业发展丧失的机会成本价值作为生态补偿的下线,以生态系统服务总价值乘以衡水湖地区的生态价值系数55.1%作为生态补偿的上线,则衡水湖国家级自然保护区生态补偿的合理标准范围为16.94亿~39.56亿元/a。  相似文献   

5.
Grey mullet ponds situated in Arcachon Bay on the western Atlantic coast of France, display contrasting mixohaline habitats.The pattern of osmoregulation of Chelon labrosus and Liza ramada exhibiting differential penetration of fish ponds has been investigated. Key variables of salinity and temperature have been considered. The tolerances to low salinities and to fresh water have been determined. The dynamics of variation in plasma osmotic pressure and major plasma electrolytes (Na+, Cl?, K+) were studied in terms of: (1) gradual adaptation to a decreasing salinity gradient; (2) effects of a long-term adaptation in fresh water; (3) effects of low temperatures on sea water adapted fish.Both species can adapt to a wide range of salinities; however, while L. ramada show a good hypoosmotic regulation, with no alteration in plasma concentration over a wide range of salinity and after a long stay (5 months) in fresh water, C. labrosus cannot live for long periods of time in a wholly fresh water habitat. Both field samples obtained from thick-lipped grey mullets forced to stay in a freshwater pond and experimentally adapted fish showed, after 3 months, an unequivoqual decrease in plasma sodium and chloride, and plasma osmolality decreased to the same extent; this pattern of no compensation is bound, sooner or later, to end in death. The inability of C. labrosus to develop a long-term hypoosmoregulation in fresh water is referred to salinity preferences which probably limit the upstream penetration of this species.Plasma osmolality and major electrolytes (sodium and chloride) increased in cold (4 °C) sea water. This response might be due to a reduced ability of grey mullets to osmoregulate in cold waters. In the poly-mesohaline ponds, Winter drop in temperature (4–6 °C) causes grey mullets to migrate to the meso-oligohaline ponds where the mean temperature is more elevated (8 °C) and temperature changes less rapid (6–9 °C).  相似文献   

6.
  • 1. Ariake Bay, which is located in western Japan, has a large tidal range (>6 m) and a vast tidal flat (200 km2). In the early 1990s, the government‐managed Isahaya Reclamation Project began in the western part of Ariake Bay. A 16‐km2 area of tidal flat in the inner part of Isahaya Bay was destroyed through reclamation and separated from the sea by a dyke, which created land and a freshwater reservoir.
  • 2. Since the initiation of the project, fishery yields around Isahaya Bay have dramatically decreased. The objective of this study was to clarify the relationship between the work associated with the Isahaya Reclamation Project and the recent environmental deterioration in Ariake Bay, with references to present sediment thickness and organic matter content, and hypoxic water distributions in Isahaya Bay.
  • 3. The organic matter load from the reservoir has increased since the initiation of the reclamation project and has been associated with a thick layer of fine sediment at the bottom of Isahaya Bay. The thickness of fine sediment and the total organic carbon content were higher in Isahaya Bay than in the freshwater reservoir.
  • 4. Based on measurements in August 2001, hypoxic water spread widely in and around Isahaya Bay; the lowest dissolved oxygen (DO) concentration (0.53 mg L?1) was observed just outside the dyke. An analysis based on a two‐layered box model using data obtained in August 2001 showed that the DO consumption rate in the bottom layer was high (0.61 mg O2 L?1 day?1), and that 22–41% of the total organic carbon load needed to induce the hypoxic water was derived from the reclamation area.
  • 5. Our findings strongly suggest that enclosed seas may suffer from eutrophic and hypoxic conditions because of their low seawater‐exchange rate. A comprehensive conservation programme and environmental assessment including physical and material transport processes in the system is needed to manage the environment of the enclosed sea.
Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   

7.
鉴于乡村水塘长期得不到重视与保护,将导致水塘景观逐渐丧失的现状,通过构建水塘景观生态网络并优化调控途径,对区域水塘景观规划和生态保护具有重要意义。以重庆市梁平区仁贤镇为例,基于2019年遥感影像和高程数据,运用空间统计分析、景观格局指数、水文分析及最小累积阻力模型等方法,探讨水塘空间分布规律并构建水塘景观生态网络。结果表明:(1)水塘空间分布深受海拔、坡度和聚落等因素影响,集中分布于低海拔(420.00~447.74 m)、低坡度(0~6°)、邻近聚落(0~40 m)区域;(2)构建水生态网络和生境网络以提供水塘连通性,水塘斑块、汇水节点、自然水系及雨水径流共同构成水生态网络体系,其中雨水径流282条,汇水节点199个,目前仅有40个水塘位于汇水节点处;生境网络体系中,潜在生态廊道351条,主要由农田与林地构成;(3)水塘景观生态优化调控途径可从空间配置、生态网络、生境质量及景观构成4个方面进行。研究结果可为水塘景观保护、小微湿地建设及乡村环境改善提供参考。  相似文献   

8.
海洋生态补偿研究综述   总被引:1,自引:0,他引:1  
海洋生态系统是人类生存与发展必不可少的基础条件,应从整个生态系统的角度来认识海洋生态资源的价值。近年来,为了协调海洋生态环境保护和经济发展的矛盾,沿岸各国在海洋资源综合管理中纳入了生态系统方法,这使得开展海洋生态补偿成为必然趋势。近年来,国内外学者在生态经济学研究成果的基础上开展对海洋生态补偿课题的相关研究。国外学者针对海洋生态补偿类型、手段等问题提出自己的观点。国内学者在海洋生态补偿方面的研究主要集中在三个方面:对海洋生态价值的探讨;,寸海洋生态系统服务及价值评估的研究;对海洋生态补偿机制的初步探讨。文章在对国内外相关研究成果进行分析的基础上,认为目前海洋生态补偿研究存在诸多不足,今后的研究应致力于海洋生态损失的计量方法与模型研究、海洋生态补偿量的模型研究及构建海洋生态补偿机制。  相似文献   

9.
我国海洋牧场建设回顾与展望   总被引:19,自引:12,他引:7  
杨红生 《水产学报》2016,40(7):1133-1140
海洋牧场是基于海洋生态学原理和现代海洋工程技术,充分利用自然生产力,在特定海域科学培育和管理渔业资源而形成的人工渔场。海洋牧场的特点包括以增加渔业资源量为目的、具有明确的边界和权属、苗种主要来源于人工育苗或驯化、通过放流或移植进入自然海域、主要以天然饵料为食和对资源实施科学管理等。早在1965年,我国学者曾呈奎先生就原创性地提出在海洋中通过人工控制种植或养殖海洋生物,建设"牧场"的理念。上世纪八十年代以来,我国海洋牧场经历了从增殖放流、人工鱼礁建设到系统化的海洋牧场发展过程,在取得巨大成就的同时,也面临着海洋牧场的涵义应用过于宽泛、缺乏统筹规划和科学论证、忽视海洋牧场生态作用以及忽视项目评估和系统管理等问题。展望未来,我国的海洋牧场建设应在"生态优先、陆海统筹、三产贯通、四化同步、创新跨越"的发展理念指导下,加强海洋牧场建设的宏观引导、推动海洋牧场体系化建设、实施海洋牧场企业化运营,在获得经济效益的同时,实现产业繁荣和保持健康生态系统的和谐统一。  相似文献   

10.
胶州湾是我国重要的菲律宾蛤仔(Ruditapes philippinarum)养殖基地,为探究湾内菲律宾蛤仔的生态容量及其碳汇功能,本研究采用Ecopath模型法评估了胶州湾菲律宾蛤仔的生态容量,并利用Ecosim模块动态分析了菲律宾蛤仔生物量扩大对胶州湾生态系统结构与功能特征的潜在影响,同时估算了胶州湾菲律宾蛤仔个体及种群水平的碳收支情况。结果显示,胶州湾菲律宾蛤仔的生态容量为239.9 t/km2,虽然整体水平尚未达到生态容量,但局部养殖区域已远超出了菲律宾蛤仔的生态容量;当胶州湾菲律宾蛤仔生物量从当前增加至生态容量时,生态系统总流量、容量、优势度和循环指数分别提高了16.0%、3.9%、47.1%和103.0%,而熵值降低了10.4%,表明此时生态系统具有更高的成熟度与稳定性,但菲律宾蛤仔生物量扩大至生态容量10倍时会对生态系统产生不利影响甚至崩溃;菲律宾蛤仔个体在1个养殖周期内约摄取3 310.1 mg C,其中约46.2%的碳沉降至海底,约13.2%的碳通过收获移出,如按菲律宾蛤仔生物量达到生态容量时计算,胶州湾每年将有1.5万t碳以生物沉积形式沉降至海底,有0.6万t碳以收获形式移出。研究结果为指导菲律宾蛤仔增养殖产业的健康可持续发展、阐明菲律宾蛤仔的碳汇功能提供了理论依据与数据支撑  相似文献   

11.
  • 1. We conducted a preliminary study of the effects of a shrimp beam trawl and prawn traps on sea whips (Halipteris willemoesi (Cnidaria: Octocorallia: Pennatulacea)) at two bays on Clio Channel, south central coast of British Columbia, Canada. Video and grabs surveys were conducted to estimate abundance and make observations on sea whips and their habitat.
  • 2. No adult sea whips were caught in six beam trawls. In 600 prawn (Pandalus platyceros) trap sets at Turnour Bay, 30 sea whips were found entangled in the gear and of these 50% of the colonies were damaged. The length of broken sea whips ranged from 0.09 to 1.03 m. At Turnour Bay, the density of adults observed in video surveys ranged from 7.1 to 14.3 m?2. Juvenile density in grab samples ranged from 53 to 123 m?2 and a few adults were also caught. The lengths of intact adult sea whips caught in traps and grabs ranged from 0.20 to 1.98 m and juveniles from 0.3 to 0.7 cm.
  • 3. Fewer adult sea whips (<0.1 m?2) were seen in Bones Bay, where sediments were muddier (grain size <0.25 mm: 84.6 to 97.2%) relative to Turnour Bay (grain size <0.25 mm: 71.4 to 85.9%). Bottom water characteristics at the two bays were similar. Seasonal temperature range was 7.5–8.4°C, salinity 30.63–31.49 psu, and dissolved oxygen 2.76–5.97 mg L?1. Differences in sediment characteristics and food availability may have been a factor influencing differences in abundance of sea whips between the two bays.
  • 4. Further data are needed to investigate the effects of trawling and trapping on sea whips, as sample sizes were small in the present study and only two gear types were evaluated. Studies of effects of otter trawling and heavier traps, such as those used for Dungeness crab (Cancer magister), are warranted.
Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   

12.
Annual sedimentation, re-suspension rates and contents of particulate organic carbon (POC), particulate organic nitrogen (PON) and total phosphorus (TP) in the sediment were investigated in two sea cucumber culture ponds at Rongcheng, Shandong Province, China. The results showed that the average flux of total particulate matter in the ponds was 22.1 g m2 d−1. The average re-suspension rate of the sediment in the ponds was 81.7%. The re-suspension rates in spring and autumn were higher than those in summer and winter. The mean contents of POC, PON and TP in the sediment of the ponds were 4.4, 0.5 and 0.6 (mg g−1), respectively, and the mean contents of Chlorophyll a (Chl a) and pheophytin in the sediment were 8.1 and 12.1 μg g−1 respectively. The POC, PON and TP contents in the sediment of the ponds increased during the period of sea cucumber aestivation (summer) and hibernation (winter), while they decreased during the feeding periods. The organic matter accumulation rate and the contents of POC, PON, TP, Chl a and pheophytin in the sediment were even lower than those in the pond without sea cucumber (P<0.05). The results demonstrated that sea cucumber culture can effectively stop nutrient accumulation at the bottom of the cucumber culture ponds.  相似文献   

13.
对虾池塘养殖生态系的研究进展   总被引:4,自引:1,他引:4  
了解养殖生态系统结构和功能对指导健康养殖至关重要。本文概述了对虾池塘养殖生态系统的基础研究和应用研究现状及存在问题,并从生态学角度阐述了对虾养殖生态系统的特点,提出对虾养殖生态系统的建立和维持要以去除过剩的营养盐为目标,注重进行物流和能流畅通的立体养殖体系和多池循环的综合养殖体系的定量研究与模拟,以实现对虾养殖的可持续发展。  相似文献   

14.
为开发山东半岛南部浅海养殖,在苏山岛海域采用“顺流筏架、大筏距、多浮力、浅水层”等技术,大面积养殖海带成功,1992年试养200亩,平均每亩效益1583元;1993年试养450亩,平均每亩效益1638元,皆高于荣成桑沟湾海区海带养殖效益。  相似文献   

15.
为了解不合理的集约用海造成的海洋生态环境问题,优化用海技术,需开展集约用海工程对海域生态环境影响的评估。为此,采用多级框架结构法构建指标体系,从海洋生态系统层面,构建了基于海洋环境和海洋生物群落的集约用海对海域生态环境影响的评估指标体系;在此基础上,结合我国海洋生态环境监测和评估现状,确定了各评价因子的评估标准及评估等级;利用综合赋值评价法,建立了集约用海对海洋生态环境影响的综合评价模型,并在曹妃甸及邻近海域开展了实证研究,结果表明集约用海已经使曹妃甸及邻近海域生态环境受到较大影响,生态环境质量一般,其中对海洋生物群落的影响程度大于对海洋环境的影响程度。  相似文献   

16.
本研究以我国北方典型岸基半开放刺参(Apostichopus japonicus)养殖池塘为对象,利用高通量测序技术构建冻融期刺参养殖池塘沉积物菌群16S rRNA基因测序文库,解析封冰期、融冰期和化冰期刺参养殖池塘沉积物菌群结构特征,并查明影响菌群结构的主导环境因子。结果显示,冻融期刺参养殖池塘沉积物菌群丰度和多样性表现为整体下调趋势,在融冰初期呈现显著性波动(P<0.05)。冻融期刺参养殖池塘沉积物菌群结构呈现显著性差异,封冰期、融冰期和化冰期差异菌群分别隶属于厚壁菌门(Firmicutes)、酸杆菌门(Acidobacteria)和软壁菌门(Tenericutes)。尽管不同阶段微生物相对丰度比例不同,但第一优势菌门均隶属于变形菌门(Proteobacteria),相对丰度高于49.04%;次优势菌门则呈现出显著性变化,其中,封冰期为拟杆菌门(Bacteroidetes),融冰期为绿弯菌门(Chloroflexi)和放线菌门(Actinobacteria),化冰期为浮霉菌门(Planctomycetes)。环境因子与菌群相关性分析表明,冻融期刺参养殖池塘沉积物菌群结构与环境因子具有显著相关性(P<0.05),温度、盐度、总氮和总有机碳是沉积物菌群的主导环境因子。本研究将为刺参养殖池塘精细化管理提供理论依据。  相似文献   

17.
A high rate algal pond (HRAP) system was used to treat effluent from a recirculating sea water aquaculture system in southern France. Dicentrarchus labrax L. were farmed at a high density, with effluents containing an average of 10 mg L?1 dissolved inorganic nitrogen (DIN) and 1.3 mg L?1 reactive phosphorus (RP). On a yearly basis, the algal pond removed 59% of the dissolved nitrogen and 56% of the phosphorus input, which was converted into 3.3 kg DW m?2 algae. Green macroalgae were dominant throughout the year and the algal biomass mirrored the seasonal changes in daily irradiance and temperature. This first year study supports the possibility of treating marine aquaculture wastes using HPAPs, although conditions will have to be found to mitigate the strong influence of climate on the algal community during winter. During the more temperate season, only 150 m2 of treatment ponds would be necessary to remove the nutrients produced by 1 ton of fish. Treated water was characterized by a high pH, elevated levels of dissolved oxygen (midday value) and low concentrations of nutrients and suspended solids. The absence of toxic phytoplankton meant that the water could be recycled through the farm tanks.  相似文献   

18.
评估大长山生态化开发示范区海洋生态服务价值,为生态化开发建设效果评估提供参考依据。示范区2012年投放塔型钢筋混凝土人工鱼礁改造海底环境,2013年初步进行了建设,养殖品种为刺参、皱纹盘鲍等海珍品。参照《海洋生态资本评估技术导则》,对开发示范区2012-2014年供给服务、调节服务、文化服务3组,养殖生产、捕捞生产、氧气生产、气候调节、废弃物处理、休闲娱乐、科研服务等7大类生态服务价值进行评估。示范区建设前的2012年生态服务价值4 178.65万元,示范区建设后2014年生态服务价值5 373.87万元,增加28.60%。2014年生态服务价值中,养殖生产价值5 068.80万元,较2012年增长1 096.30万元、增幅27.60%,刺参生物量较2012年增加83.3 t、增幅43.09%。文化服务中,2012、2013年示范区建设单位并未对海域进行旅游开发,当年旅游收入均为0;在示范区建设酒店后,2014年接待游客近千人次,直接旅游收入达到60.30万元。下一步应进一步完善评估模型,特别是需要获取准确统计数据,以便准确评估示范区的生态价值。  相似文献   

19.
The efficacy of a commercial microbial product was tested in commercial tiger shrimp, Penaeus monodon (Fabricius), ponds for one culture period in Kuala Selangor, Malaysia. Four ponds with replicates for treatment and control were used. The pond bottom was dried but the organic sludge was not removed as normally practised in pond preparation. The ponds were stocked with 15 post‐larvae at the rate of 31.m?2. Physical, chemical and biological parameters of the pond were analysed every 2 weeks during the culture period. Water quality parameters remained within the optimum range for shrimp culture except for ammonia‐nitrogen being significantly higher in control ponds and silica in treated ponds. Benthic organisms were not found in any of the ponds. The average counts of different bacteria were not significantly higher in treated ponds than control. Because of poor health, the shrimp were harvested earlier (72 days) than the usual 120 days. An average of 875.60 ± 67.00 kg shrimp ha?1 was obtained in treated ponds with a feed conversion ratio (FCR) of 1.57 ± 0.10 and survival rate of 42.35 ± 5.37% compared with 719.50 ± 130.94 kg shrimp ha?1, 2.99 ± 0.70 and 21.25 ± 3.26%, respectively, in control ponds. Neither the microbial product nor the frequent water exchange was effective in overcoming the problems caused by the poor pond bottom.  相似文献   

20.
基于大型底栖动物的桑沟湾不同养殖区底栖生境健康评价   总被引:1,自引:1,他引:0  
为了解桑沟湾养殖区大型底栖动物的动态变化以及底栖生境的健康状况,于2019年5-9月采集了中国北方典型养殖海湾桑沟湾不同养殖区(藻类、贝类和网箱养殖区)大型底栖动物样品,分析了不同养殖区大型底栖动物的种类、组成、数量分布、群落结构及生物多样性等群落特征,运用多样性指数、AMBI和M-AMBI指数法评价了不同养殖区底栖生境健康状况的时空变化。调查共鉴定出大型底栖动物56种,其中多毛类31种,甲壳类10种,软体动物9种,棘皮动物4种,其他类2种,大型底栖动物的优势种主要为多毛类,以污染耐受种为主;调查期间,贝类养殖区和网箱养殖区的群落多样性指数H''呈现下降趋势,表明贝类养殖活动和网箱养殖活动已经造成沉积物中有机物颗粒过度积累。ABC曲线显示,7月桑沟湾养殖区开始受到干扰,8月和9月受到中等程度的干扰。AMBI和M-AMBI指数评价显示桑沟湾养殖区域底栖生态系统处于轻度或中度干扰状态,底栖生境健康状况处于高等或者良好的状态。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号