Ecological coherence of Marine Protected Areas: New tools applied to the Baltic Sea network     

Per R. Jonsson  Per‐Olav Moksnes  Hanna Corell  Erik Bonsdorff  Martin Nilsson Jacobi 《水产资源保护:海洋与淡水生态系统》2020,30(4):743-760

1. Spatial connectivity is an essential process to consider in the design and assessment of Marine Protected Areas (MPAs). To help maintain and restore marine populations and communities MPAs should form ecologically coherent networks. How to estimate and implement connectivity in MPA design remains a challenge.
2. Here a new theoretical framework is presented based on biophysical modelling of organism dispersal, combined with a suite of tools to assess different aspects of connectivity that can be integrated in MPA design. As a demonstration, these tools are applied to an MPA network in the Baltic Sea (HELCOM MPA).
3. The tools are based on the connectivity matrix, which summarizes dispersal probabilities, averaged over many years, between all considered areas in the geographic target area. The biophysical model used to estimate connectivity included important biological traits that affect dispersal patterns where different trait combinations and habitat preferences will produce specific connectivity matrices representing different species.
4. Modelled connectivity matrices were used to assess local retention within individual MPAs, which offers indications about the adequacy of size when MPAs are considered in isolation. The connectivity matrix also provides information about source areas to individual MPAs, e.g. sources of larvae or pressures such as contaminants. How well several MPAs act as a network was assessed within a framework of eigenvalue perturbation theory (EPT). With EPT, the optimal MPA network with respect to connectivity can be identified. In addition, EPT can suggest optimal extensions of existing MPA networks to enhance connectivity. Finally, dispersal barriers can be identified based on the connectivity matrix, which may suggest boundaries for management units.
5. The assessment of connectivity for the HELCOM MPA are discussed in terms of possible improvements, but the tools presented here could be applied to any region.

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Survival and growth of local and transplanted blue mussels (Mytilus trossulus, Lamark)     

Jenia F Yanick  John W Heath  & Daniel D Heath 《Aquaculture Research》2003,34(10):869-875

Consumer demand for fish and shellfish has led to an increase in aquatic species movement for aquaculture purposes. One potential drawback to the successful transplantation of animals for aquaculture is unpredictable performance due to local adaptation effects. This study used a common environment experiment to examine the potential for local adaptation in Mytilus trossulus (Lamark) on the east coast of Vancouver Island, British Columbia (BC). Newly settled mussels were collected from two sites, Chemainus and Quadra Island (approximately 150 km apart), reared in cages at the Quadra collection site, and mortality and shell length were monitored. Mussels were cage‐reared for 384 days with an overall survival of 59% (Quadra) and 39% (Chemainus). The Quadra mussels were initially smaller (5.07 mm) than the Chemainus mussels (5.90 mm), but the two were similar at the end of the experiment (23.5 and 23.6 mm). Transplanted mussels had a significantly higher mortality over the course of the experiment, primarily due to a severe episode in the early summer, and had significantly lower relative growth rates at three of 11 measurement dates. Overall, the local mussels performed better than the transplanted mussels. This study demonstrates the potential for local adaptation effects between populations of mussels separated by only a relatively small geographic distance.  相似文献   

The use of clove oil as an anaesthetic for the longfinned eel, Anguilla reinhardtii (Steindachner)     

Chris T Walsh  & Bruce C Pease 《Aquaculture Research》2002,33(8):627-635

To handle large river eels during procedures such as measuring and tagging for field and aquaculture studies, they must be anaesthetized. During our initial biological studies of Anguilla reinhardtii (Steindachner) it was found that the anaesthetic benzocaine was relatively expensive and elicited a variable response, even when used at relatively high concentrations. Human health risks are also a concern when using benzocaine, as some of the eels may later be sold for human consumption. Therefore, experiments were done to evaluate the use of clove oil (a safe, naturally occurring product) for anaesthesia of this species at a range of temperatures (17 and 25 °C) and salinities (0–32 g L^?1). It was found that clove oil provided a suitable anaesthetic response through this wide range of temperatures and salinities. Response times were found to be relatively variable for both benzocaine and clove oil. This variability may be related to stress, environmental factors, or the condition of the fish. Clove oil is recommended for anaesthesia of anguillid eels because it is effective, relatively inexpensive, and poses little risk to human health.  相似文献   

浅谈云南地方特色产品与旅游市场的结合——以“杨林肥酒”为例     

方婕 《云南农业大学学报(自然科学版)》2014,8(5):132-136

“杨林肥酒”是一款百年历史的文化名酒,也是中国现存唯一的绿酒,具有浓郁的地方特色和丰富的地方文化内涵.云南是旅游大省,伴随着旅游业的发展,云南地方特色产品应抓住机遇,不断拓展生存与发展空间.本文以云南“杨林肥酒”为例,立足于其丰富的历史文化,通过阐述“杨林肥酒”的历史渊源及产品的发展演变,具体分析“杨林肥酒”结合旅游开发的优势,提出把“杨林肥酒”融入云南旅游市场的思路,作为一种促使云南地方特色产品做大做强的路径探索.  相似文献   

涉农企业介入、地方政府引导对农户种植决策的影响研究——以甘肃省民乐县马铃薯种植为例     

夏莲 《安徽农业大学学报》2014,(3):60-67

构建农户的种植决策如何受到市场、企业合约以及政府政策影响的理论分析框架,以甘肃省民乐县马铃薯产业发展为例,实证农户马铃薯种植决策如何受到涉农企业介入以及地方政府引导的影响。研究发现涉农企业介入对当地农业市场的完善显著正向影响了农户选择种植马铃薯的决策,但是以市场联接为主的松散合作模式对农户马铃薯种植决策并没有起到积极的推动作用,而地方政府在对主导产业的推广及相应政策支持在涉农企业与农户的紧密合作中发挥了重要的作用。  相似文献   

The ability of clove oil and MS-222 to minimize handling stress in rainbow trout (Oncorhynchus mykiss Walbaum)   总被引：1，自引：0，他引：1  

Glenn N Wagner  Thomas D Singer  & R Scott McKinley 《Aquaculture Research》2003,34(13):1139-1146

The effects of 60‐mg L^?1 clove oil and 60‐mg L^?1 tricaine methanesulphonate (MS‐222) on the blood chemistry of rainbow trout were compared after exposure to handling stress via caudal puncture blood sampling. Fish sampled by caudal puncture and subsequently exposed to anaesthetics showed a typical handling stress response over a 48‐h period. There were no significant differences between the responses of fish exposed to equal concentrations of clove oil and MS‐222, with the following exceptions: the blood glucose at full anaesthesia, and lactate at full recovery increased significantly in the clove oil‐exposed fish. In a subsequent experiment, the stress response observed in fish sampled by caudal puncture and exposed to clove oil and MS‐222 was compared with a non‐anaesthetized control group. The increases in plasma cortisol levels were significantly lower at recovery in fish treated with either anaesthetic compared with the control fish. Fish exposed to MS‐222 had significantly higher cortisol levels at 1 h. These findings show that few differences exist between the anaesthetic effects of clove oil and MS‐222 on the physiological response of fish to stress. However, clove oil is more effective at reducing the short‐term stress response induced by handling and blood sampling, and is recommended as an alternative fish anaesthetic.  相似文献   

Fish–habitat relationships and fish conservation in small coastal streams in southern Spain     

Miguel Clavero  Francisco Blanco‐Garrido  Jos Prenda 《水产资源保护:海洋与淡水生态系统》2005,15(4):415-426

• 1. Studies dealing with the fish fauna of coastal streams are scarce in the scientific literature, particularly those from Mediterranean climates. Owing to their small size, these systems suffer extreme seasonal fluctuations, following the typical Mediterranean flood–drought cycle and leading to a high risk of extinction to freshwater fish.
• 2. This work analyses fish distribution in 14 stream stretches belonging to eight basins in the northern sector of the Strait of Gibraltar (southern Spain). Fish–habitat relationships were studied through multivariate ordination techniques at two scales: basin and stretch.
• 3. A principal components analysis clearly discriminated larger and more sinuous basins from smaller and steeper ones. This ordination was related to the non‐migratory freshwater fish species richness and to the total number of fish species present in the middle reaches of each basin.
• 4. The main sources of variation in community composition and habitat characteristics in the different stretches were related to a clear upstream–downstream gradient, along which total species richness increased.
• 5. These small coastal basins are inhabited by two highly endangered species, Andalusian toothcarp (Aphanius baeticus) and Iberian chub (Squalius pyrenaicus), and have similar or higher overall freshwater species richness than larger adjacent basins. The near absences of flow regulation and introduced species make these streams one of the few types of Iberian aquatic system where unaltered fish–habitat relationships can be studied.

Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   

DRAINMOD模型参数灵敏度分析   总被引：1，自引：0，他引：1  

陈丽群  胡铁松 《节水灌溉》2011,(10):37-41

参数灵敏度分析对于合理确定模型参数具有重要意义。以五道沟水文水资源实验站为研究区域,采用局部灵敏度分析方法分析了DRAINMOD模型逐日排水量对侧向饱和导水率k、排水系数D.C以及地表最大积水深度Sm的灵敏度。理论分析与计算表明：不同的参数在不同的阶段对排水过程的影响呈现不同的规律,土壤侧向饱和导水率对排水过程的模拟结...  相似文献   

Topical wound anaesthesia: efficacy to mitigate piglet castration pain     

ML Sheil  M Chambers  B Sharpe 《Australian veterinary journal》2020,98(6):256-263

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新疆地方文献信息服务探究     

周亚丽 《农业网络信息》2015,(1):107-109

本文就石河子大学新疆地方文献信息服务的现状进行客观分析,针对信息服务中存在的问题,提出开展新疆地方文献信息服务应采取的措施。  相似文献