Stocking effectiveness of hatchery-released kuruma prawns estimated by two-stage sampling of commercial catch in Ariake Sound, Japan

ABSTRACT:    To evaluate the stocking effectiveness of the kuruma prawn Penaeus japonicus , a two-stage sampling survey of Gensiki bottom-drift-netters was carried out in Ariake Sound, Saga Prefecture, Japan. A total of 471 000 hatchery-produced juveniles, marked by cutting off the right uropods, was released. Thirty-three fishing days were randomly drawn from four boats, which were selected from the 80 boats operating in the fishery. All prawns caught on the selected days were examined, and the hatchery-produced individuals were identified by their regenerated uropods. A telephone survey of all boats was also conducted, to determine the number of fishing days. A total of 286 marked prawns were caught on the survey days for the Saga area in Ariake Sound, from the last half of July to the first half of September 2002. The recapture rate and standard error were estimated at 0.76 ± 0.52%. Economic efficiency was estimated at 0.28 ± 0.02. Strategies for sampling schemes and stock recovery are also discussed.     

日光温室后屋面内设反光幕环境效应分析

为研究日光温室后屋面内设反光幕对室内环境和植株的影响,在秋冬季节测定了反光幕对日光温室室内光强、温度、湿度和植株株高、茎粗的影响。结果表明:后屋面张挂反光幕有补光效果,室内光照强度平均增加7%~14%,可缓解温室内南北方向光分布不均,室内温度增加1.8~7.2℃;同时温室内植株茎粗平均提高1mm,且改善了室内植株南北高度不均的问题。因此,冬季在温室后屋面张挂反光幕,既可以补光又不影响后墙正常蓄热保证室内温度。     

Evaluation of different approaches to individual tree growth and survival modelling using data collected at irregular intervals - a case study for Pinus patula in Kenya

Background： The minimum set of sub-models for simulating stand dynamics on an individual-tree basis consists of tree-level models for diameter increment and survival. Ingrowth model is a necessary third component in uneven-aged management. The development of this type of model set needs data from permanent plots, in which all trees have been numbered and measured at regular intervals for diameter and survival. New trees passing the ingrowth limit should also be numbered and measured. Unfortunately, few datasets meet all these requirements. The trees may not have numbers or the length of the measurement interval varies. Ingrowth trees may not have been measured, or the number tags may have disappeared causing errors in tree identification. Methods： This article discussed and demonstrated the use of an optimization-based approach to individual-tree growth modelling, which makes it possible to utilize data sets having one or several of the above deficiencies. The idea is to estimate all parameters of the sub-models of a growth simulator simultaneously in such a way that, when simulation begins from the diameter distribution at the first measurement occasion, it yields a similar ending diameter distribution as measured in the second measurement occasion. The method was applied to Pinus patula permanent sample plot data from Kenya. In this dataset, trees were correctly numbered and identified but measurement interval varied from 1 to 13 years. Two simple regression approaches were used and compared to the optimization-based model recovery approach. Results： The optimization-based approach resulted in far more accurate simulations of stand basal area and number of surviving trees than the equations fitted through regression analysis. Conclusions： The optimization-based modelling approach can be recommended for growth modelling when the modelling data have been collected at irregular measurement intervals.     

垄茶高速公路边坡生态恢复中先锋植物的选择研究

指出了高速公路的建设对环境具有较强的破坏作用,不仅影响景观,还影响植被的生长。为了能尽快恢复植被的生长,对高速公路边坡生态恢复中先锋树种的选择进行了研究。阐述了边坡绿化的功能,提出了高速公路边坡先锋植物的选择原则和习性要求,分析了垄茶高速公路边坡的环境特点,并探讨了其边坡绿化的有效措施,特别是就先锋树种选择、植物的文化内涵和植物配置等方面进行了研究。提出了应用植物35种,其中包括豆科、蔷薇科、杜鹃花科、胡颓子科、桦木科、鼠李科等。其结果对国内高速公路边坡植被恢复具有较强的参考价值。     

A new large‐scale and cost‐effective restoration method for cold‐water coral gardens

1. Gorgonians dwelling on the Mediterranean continental shelf are among the most frequent fishing bycatch taxa. These species display several traits, such as long lifespans and slow growth, which make them very vulnerable to the impacts caused by fishing activities with far‐reaching and long‐lasting effects.
2. Hence, restoration and mitigation actions are crucial to enhance and speed up the natural recovery of damaged cold‐water coral gardens. Given the growing concern to develop effective and affordable restoration actions, the present study aims to propose and technically validate a new large‐scale and cost‐effective restoration method.
3. This technique, named ‘badminton method', consists of attaching bycatch Eunicella cavolini colonies to cobble supports and returning them to the continental shelf by gently throwing the gorgonian transplants directly from a boat.
4. Two consecutive field experiments were conducted in order to find the best cobble type support and gorgonian size to be used: first, to evaluate the landing efficiency of gorgonian transplants at different depths (from 5 to 30 m) and second, to evaluate their capability to maintain a correct position over time.
5. Natural cobbles with large gorgonians attached were the best option. Field results and modelling approaches suggest that the transplants would correctly land on the continental shelf seabed in a predicted area of around 60 m². Moreover, they would successfully maintain an upright position ensuring gorgonian survival over time.
6. The success of this method highlights the feasibility of large‐scale and low‐cost restoration actions with promising results for the conservation and recovery of cold‐water coral gardens.

     

Environmental and physiological conditions affecting Tetrahymena sp. infection in guppies, Poecilia reticulata Peters

Parasitic infections caused by Tetrahymena sp. constitute a serious problem in guppies, Poecilia reticulata. Tetrahymena was isolated from skin lesions of naturally infected guppies in a commercial aquaculture farm, cultured in vitro and used in subsequent experimental infections. In addition to guppies, angelfish, Pterophyllum scalare, platyfish, Xiphophorus maculates, and neontetra, Paracheirodon innesi, were susceptible, whereas tilapia (Oreochromis niloticus xO. aureus) was resistant. The ciliate had a high affinity for dead fish. Skin abrasion did not affect the infection, but fish with gas bubble disease exhibited a significantly higher infection than non-affected fish. Infection was significantly higher when fish were exposed to high levels of ammonia, high organic load and low water temperatures. Under shipment conditions, infection was significantly elevated. Full recovery was achieved at a low fish density. Results suggest that poor environmental and physiological conditions enhance infection with Tetrahymena sp.     

大棚不同地膜栽培对蔬菜生长及产量的影响

通过在大棚内进行不同地膜,研究了大棚内麻地膜覆盖对辣椒、黄瓜生长及产量的影响。试验结果表明,大棚内麻地膜覆盖栽培促进蔬菜生长,提高辣椒、黄瓜产量。麻地膜覆盖栽培辣椒、黄瓜比聚乙烯农用黑膜增产5．2％、14．5％,比CK（不覆盖）增产24．7％、23．0％,与对照相比均达到显著差异。     

甘蔗光降解地膜与普通地膜不同覆盖方式对比试验

通过新植甘蔗采用光降解地膜与普通地膜不同覆盖方式对比试验,结果表明：两种地膜全膜覆盖较半膜覆盖与不盖膜具有较好的增温保湿作用,农艺性状表现较好,增产增糖效果明显.全膜覆盖平均蔗茎产量10595kg/667m2,较半膜覆盖增产1748 kg/667m2、增19.8％,差异达5％显著水平;较不盖膜增产2650 kg/667m2、增33.4％,差异达1％极显著水平.试验实施90d未发现光降解膜降解破口迹象,降解效果不理想.     

袋栽金针菇2潮后脱袋增产技术研究

为满足商品性要求,袋栽金针菇2潮后一般不再进行出菇管理。实际上,这时的菌棒仍有出菇趋势,由于塑料皮限制其生长,且阻碍补水补养,致使无法产生商品性好的菇,培养基中养分无法利用充分。试验中割破塑料皮,采用脱袋排场盖膜法和脱袋拱棚盖膜法进行继续出菇管理,并设置对照。结果表明,2种措施可分别再出菇3潮,生物学效率分别提高34％和28％,商品性满足三级以上标准,是可推广的金针菇增产措施。     

Stewardship as a Path to Cooperation? Exploring the Role of Identity in Intergroup Conflict Among Michigan Wolf Stakeholders

Post-recovery wolf management remains controversial. In Michigan, dialogue centers on hunting wolves but controversy may be more nuanced than simple pro- or anti-hunting positions. Social identity may cause stakeholders to organize in groups and identity differences may be driving controversy. To explore stakeholder disagreement over wolf management, we conducted semi-structured key informant interviews (n = 21) about identity and stewardship in August–September 2012. Four overarching identity themes emerged regarding: (a) management objectives, (b) focal levels, (c) control methods, and (d) justifications for methods. Themes indicated two main researcher-defined identity groups. Interviewees from both groups identified six common stewardship themes: (a) bequest values, (b) ecosystem health, (c) education, (d) existence values, (e) pride in natural resources, and (f) sustainability. Findings suggest stakeholders may be conflicting over opposing identities vis-à-vis organization affiliation, which may be related to what management strategies individuals oppose. Establishing common stewardship objectives through established participation methods may help alleviate controversy.