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该研究分别采用残差修正的GM(1,1)模型和灰色拓扑预测方法对2007—2017年春(5月)、秋(10月)海州湾人工鱼礁区的溶解氧(DO)、化学需氧量(COD)、生化需氧量(BOD5)及溶解无机氮(DIN)4个指标的监测数据建立水质预测模型并选择精度较高的模型预测2018—2022年的水质变化趋势,最终利用2018年的调查数据对预测结果进行检验。结果表明,灰色拓扑模型相较于残差修正的GM(1,1)模型针对水质数据具有更好的预测精度,预测结果与2018年的调查结果较吻合,可信度较高;预测结果显示,DO和COD在2018—2022年能够保持良好的水质状态,可见人工鱼礁建设对海域水环境状况具有一定的修复作用,但BOD5和DIN存在一定的超标风险;针对灰色拓扑模型的改进仍具有很大的研究空间,有待进一步挖掘。 相似文献
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海洋通过“溶解度泵”和“生物泵”完成碳汇过程,且具有碳固存容量大、储存时间长的显著优势,可有效缓解CO2排放产生的温室效应,在应对全球气候变化中发挥着不可替代的作用。渔业是人类利用海洋的基础生产活动,对近海碳循环过程具有重要的影响,渔业碳汇是海洋碳汇不可或缺的组成部分。海洋牧场作为一种以水域栖息地修复、水生生物资源养护为主旨的新型渔业模式,通过增殖水生生物资源量,提升生物固碳量,实现渔业对海洋碳汇的扩增。本文针对我国对海洋牧场的界定,梳理了国内外对海洋牧场关键碳汇因子固碳机理及其过程和潜能等方面的研究现状,浅析了海草床、牡蛎礁等典型海洋牧场生态系统在近海碳汇扩增中的重要作用。建议在海洋牧场固碳机理与碳循环过程、海洋牧场碳汇扩增技术和海洋牧场碳汇计量方法等方面开展重点研究,以期为渔业绿色发展,扩增海洋碳汇和服务“双碳”战略提供科学参考。 相似文献
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鱼类是一个迄今尚未被认知的非常重要的微细碳酸盐沉积物的来源,对海洋固碳有着重要作用,这个发现直接影响到碳汇渔业的内涵.本研究介绍了海洋硬骨鱼类渗透压调节机制及鱼类肠道碳酸盐结晶形成与其肠细胞膜上物质转运之间的关系,着重阐述了鱼类肠道碳酸盐结晶的特征,并论述了通过对特定区域内鱼类生物量和碳酸盐排泄率数据的研究,估计出全球海洋鱼类每年可产生大约1.1亿t的碳酸钙,在海洋总碳酸盐岩泥中占14%以上.研究重点论述了海水鱼类固碳的独特优势潜力,同时,提出为了更好地确定海水鱼类养殖在碳汇渔业中的地位和作用,有必要对主要海水养殖鱼类肠道碳酸结晶物的形成量及其调控机制,碳收支动态模型进行研究,进而合理地估算和测定海水鱼类养殖的碳汇量. 相似文献
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Leonardo Lara de Carvalho Eduardo Godoy Aires de Souza Roberto Campos Villaça 《Aquaculture Research》2017,48(2):481-493
The seaweed Kappaphycus alvarezii (Doty) Doty ex P. C. Silva, a red algal species, is the main global source of Kappa carrageenan. The introduction of such exotic species in regions outside their original locale can change the community structure of the areas into which they are introduced. The possible influence of seaweed farming on the rocky reef fish assemblage was assessed in Paraty, Brazil. The reef fish assemblage in the seaweed farming area was compared before and after the commencement of farming with two undisturbed control areas. Among the ten species ranked as the most frequently occurring in each area, eight were the same. The fish community structure close to the seaweed farming area did not change from that of the control areas, over the months of the study. Neither the fish diversity and richness indices, nor the total average abundance among areas was significantly altered. The average abundance of the different trophic groups varied over time in both the farm and control areas, revealing similar patterns. These results suggest that K. alvarezii can be cultivated up to at least 50 m from a rocky coast without altering the fish community structure of the surrounding waters. 相似文献
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贝藻类碳汇功能及其在海洋牧场建设中的应用模式初探 总被引:2,自引:0,他引:2
资源管理型渔业是未来海洋渔业发展的主要方向,海洋牧场是资源管理型渔业的主要方式之一。海洋牧场建设与碳汇渔业相结合是一种全新的水生生物养护形式,以贝类养殖和藻类栽培为载体的海洋牧场建设具有广泛的应用前景。本文分析了当前中国海洋牧场建设的形式,同时对贝藻类碳汇功能及其在海洋牧场建设中的重要性进行了论述,并结合浅海海域实际条件提出建设海洋牧场合理规划建议。 相似文献
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研究不同碳源对海水水族箱脱氮系统运行效果的影响,从而为系统高效运行提供依据。结果表明,当初始硝酸盐浓度为100 mg/L时,分别以乙醇、乙酸钠、柠檬酸钠和葡萄糖作为唯一碳源,海水水族箱中硝酸盐去除效果达到99%所需时间分别为8 d9、d1、0 d和11 d。以葡萄糖和柠檬酸钠为唯一碳源时,水族箱中亚硝酸盐呈现出先积累再消耗的变化规律,亚硝酸盐峰值浓度分别为16.7 mg/L和17.6 mg/L,并分别在13d和11 d降解到0.1 mg/L以下;而分别以乙醇和乙酸钠作为唯一碳源时,水族箱中亚硝酸盐氮浓度均维持在0.1 mg/L以下。以乙醇作为唯一碳源时,水族箱中DO迅速下降,8 d时稳定在2 mg/L左右,分别投加其他3种碳源时,水族箱中DO始终维持在6 mg/L以上。除柠檬酸钠外,投加碳源后水族箱中浊度和pH未出现明显变化。 相似文献
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Stringent environmental legislation in Europe, especially in the Baltic Sea area, limits the discharge of nutrients to natural water bodies, limiting the aquaculture production in the region. Therefore, cost-efficient end-of-pipe treatment technologies to reduce nitrogen (N) discharge are required for the sustainable growth of marine land-based RAS. The following study examined the potential of fed batch reactors (FBR) in treating saline RAS effluents, aiming to define optimal operational conditions and evaluate the activated sludge denitrification capacity using external (acetate, propionate and ethanol) and internal carbon sources (RAS fish organic waste (FOW) and RAS fermented fish organic waste (FFOW)). The results show that between the evaluated operation cycle times (2, 4, and 6 h), the highest nitrate/nitrite removal rate was achieved at an operation cycle time of 2 h (corresponding to a hydraulic retention time of 2.5 h) when acetate was used as a carbon source. The specific denitrification rates were 98.7 ± 3.4 mg NO3−-N/(h g biomass) and 93.2 ± 13.6 mg NOx−-N/(h g biomass), with a resulting volumetric denitrification capacity of 1.20 kg NO3−-N/(m3 reactor d). The usage of external and internal carbon sources at an operation cycle time of 4 h demonstrated that acetate had the highest nitrate removal rate (57.6 ± 6.6 mg N/(h g biomass)), followed by propionate (37.5 ± 6.3 mg NO3−-N/(h g biomass)), ethanol (25.5 ± 6.0 mg NO3−-N/(h g biomass)) and internal carbon sources (7.7 ± 1.6–14.1 ± 2.2 mg NO3−-N/(h g biomass)). No TAN (Total Ammonia Nitrogen) or PO43- accumulation was observed in the effluent when using the external carbon sources, while 0.9 ± 0.5 mg TAN/L and 3.9 ± 1.5 mg PO43--P/L was found in the effluent when using the FOW, and 8.1±0.7 mg TAN/L and 7.3 ± 0.9 mg PO43--P/L when using FFOW. Average sulfide concentrations varied between 0.002 and 0.008 mg S2-/L when using the acetate, propionate and FOW, while using ethanol resulted in the accumulation of sulfide (0.26 ± 0.17 mg S2-/L). Altogether, it was demonstrated that FBR has a great potential for end-of-pipe denitrification in marine land-based RAS, with a reliable operation and a reduced reactor volume as compared to the other available technologies. Using acetate, the required reactor volume is less than half of what is needed for other evaluated carbon sources, due to the higher denitrification rate achieved. Additionally, combined use of both internal and external carbon sources would further reduce the operational carbon cost. 相似文献
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为了建立捕捞渔获量预测模型,实验利用2000—2016年印度洋渔获量数据,采用灰色系统理论方法,分析了影响其总渔获量的主要渔获类别,建立多种GM模型(Grey model)并进行比较,同时利用2017年与2018年的数据进行验证,得到的最优GM模型用来预测2019—2025年印度洋总捕捞渔获量。结果显示,影响印度洋总渔获量的主要类别有底层鱼类、甲壳类、中上层鱼类、其他海洋鱼类和头足类,其灰色关联度均在0.70以上,经过筛选得到的最优预测模型为GM (1, 5)和GM (1, 6),平均相对误差分别为1.83%和1.90%,灰色关联度均在0.9以上。2017年和2018年预测平均相对误差分别为3.78%和3.42%。2019—2020、2021—2025年印度洋总渔获量预测值分别为1 186万~1 290万t、1 227万~1 324万t,其主要渔获量增加可能来自中上层鱼类、头足类以及底层鱼类等。研究表明,2021—2025年印度洋总渔获量的增长幅度有限,总增长量在80万t以内,基本处于充分开发阶段,建议未来应严格控制渔业发展规模,确保印度洋海洋渔业的可持续发展和渔业资源可持续利用。 相似文献
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为了建立捕捞渔获量预测模型,实验利用2000—2016年印度洋渔获量数据,采用灰色系统理论方法,分析了影响其总渔获量的主要渔获类别,建立多种GM模型 (Grey model)并进行比较,同时利用2017年与2018年的数据进行验证,得到的最优GM模型用来预测2019—2025年印度洋总捕捞渔获量。结果显示,影响印度洋总渔获量的主要类别有底层鱼类、甲壳类、中上层鱼类、其他海洋鱼类和头足类,其灰色关联度均在0.70以上,经过筛选得到的最优预测模型为GM (1, 5)和GM (1, 6),平均相对误差分别为1.83%和1.90%,灰色关联度均在0.9以上。2017年和2018年预测平均相对误差分别为3.78%和3.42%。2019—2020、2021—2025年印度洋总渔获量预测值分别为1 186万~1 290万t、1 227万~1 324万t,其主要渔获量增加可能来自中上层鱼类、头足类以及底层鱼类等。研究表明,2021—2025年印度洋总渔获量的增长幅度有限,总增长量在80万t以内,基本处于充分开发阶段,建议未来应严格控制渔业发展规模,确保印度洋海洋渔业的可持续发展和渔业资源可持续利用。 相似文献
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- 1. An expansion of no‐take marine reserve zones of Australia's 348 000 km2 Great Barrier Reef (GBR) Marine Park from 4.6% to 33.4% of the park area is proposed in 2004. However, limited evidence currently exists that no‐take marine reserves on the GBR have increased abundance of reef fish targeted by fisheries. This study provides such evidence for inshore reefs of the GBR.
- 2. Underwater visual surveys were used to estimate the effect of no‐take reserves on abundance of species targeted by hook‐and‐line fisheries around the Palm, Whitsunday and Keppel Islands, spanning 600 km of the length of the GBR. The reserves had been zoned ‘no fishing’ for 14 yr.
- 3. Densities of Plectropomus spp. and Lutjanus carponotatus, both targeted by fisheries, were much higher in protected zones than fished zones in two of the three island groups. Plectropomus spp. were 3.6 and 2.3 times more abundant in protected than fished zones of the Palm and Whitsunday island groups. L. carponotatus were 2.3 and 2.2 times more abundant in protected zones than fished zones of the Whitsunday and Keppel island groups.
- 4. The biomasses of Plectropomus spp. and L. carponotatus were significantly greater (3.9 and 2.6 times respectively) in the protected zones than fished zones at all three island groups.
- 5. Legal minimum sizes of Plectropomus spp. and L. carponotatus are ?38 cm and 25 cm TL respectively. There were significantly higher densities and biomasses of Plectropomus spp. >35 cm TL (density: 3.8 times; biomass: 5.1 times) and L. carponotatus >25 cm TL (density: 4.2 times; biomass: 5.3 times) in protected zones than fished zones at all three island groups.
- 6. No significant difference in abundance between protected and fished zones was found for two species not captured by fisheries (Siganus doliatus and Chaetodon aureofasciatus), and there were no significant differences in benthic characteristics between protected and fished zones.
- 7. Results suggest that no‐take marine reserves have increased stock biomass of targeted fish species on inshore GBR reefs.