池塘养殖刺参腐皮综合征发病环境因素分析

通过对2014年7—8月山东省青岛市红岛邵哥庄(SGZ)和宿流(SL)两个社区的发生刺参腐皮综合征和未发病刺参养殖池的环境因子跟踪监测和对比,解析发病的原因。从发病前至发病后,分别监测了两地多个池塘水体中的4类可培养细菌(总异养菌、弧菌、硝化细菌和硫化细菌)和6项理化参数(温度、p H、盐度、溶解氧、无机氮、COD),以及沉积环境中6类可培养细菌(总异养菌、弧菌、硝化细菌、硝酸盐还原菌、硫化细菌、硫酸盐还原菌)和4项理化参数(pH、氧化还原电位、硫化物、有机碳)。结果表明,刺参发病时,邵哥庄发病池(SGZ-1~#)环境中细菌数量与未发病对照池(SGZ-2~#)无显著差异,但温度高达25.94℃,盐度低至24.47,均超过刺参耐受限度。水体NO_2-N含量为79.56μg/L,沉积物中硫化物含量为221.1 mg/g,均高于对照池;宿流发病池SL-南2弧菌数量(1.85×10~4 CFU/mL)在发病当日明显升高,高于对照池SL-北1和邵哥庄社区的发病池,而发病池的理化指标反而好于对照池。由此推断,邵哥庄社区的刺参发病与池塘理化指标突变有密切关系,而宿流的刺参发病与病原菌数量激增有密切关系。因此,应从理化指标和病害生物两方面对刺参病害进行预警及采取防治措施。     

鱼类与水环境间相互关系的研究回顾和设想

鱼类是湖泊生态系统中较高级的消费者,通过上行效应和下行效应与环境间存在着紧密的相互作用关系。湖泊环境等理化因子的变化通过上行效应改变鱼类群落结构和数量,而鱼类群落结构的变化通过营养级联和下行效应对水体的理化特征以及其它生物的组成、分布、丰度、生物量等水生态系统结构与功能的许多方面产生影响。[第一段]     

Long-term variability in spawning stock age structure influences climate–recruitment link for Barents Sea cod

Fish populations may spawn a vast number of offspring, while only a small and highly variable fraction of a new cohort survives long enough to enter into the fisheries as recruits. It is intuitive that the size and state of the spawning stock, the adult part of the fish population, is important for recruitment. Additionally, environmental conditions can greatly influence survival through vulnerable early life stages until recruitment. To understand what regulates recruitment, an essential part of fish population dynamics, it is thus necessary to explain the impact of fluctuations in both spawning stock and environment, including interactions. Here, we examine if the connection between the environment and recruitment is affected by the state of the spawning stock, including biomass, mean age and age diversity. Specifically, we re-evaluate the hypothesis stating that recruitment from a spawning stock dominated by young fish and few age classes is more vulnerable to environmental fluctuations. We expand upon earlier work on the Barents Sea stock of Atlantic cod, now with data series extended in time both backwards and forwards to cover the period 1922–2019. While our findings are correlative and cannot prove a specific cause and effect mechanism, they support earlier work and strengthen the evidence for the hypothesis above. Furthermore, this study supports that advice to fisheries management should include considerations of environmental status.     

Variability in conspecific predation among longnose lancetfish Alepisaurus ferox in the western Indian Ocean

ABSTRACT:   Conspecific predation among longnose lancetfish Alepisaurus ferox was investigated in four spatio-temporal strata of the western Indian Ocean. The cannibalism level varied from 0 to 45.5% by frequency of occurrence and was negatively related with abundance of non-evasive prey (such as crustaceans Charybdis smithii and Natosquilla investigatoris ) and foraging success. Predation by lancetfish is often described as a non-selective process, constrained by local prey availability and by its feeding speed during an attack of prey. Our results show that lancetfish may adapt its opportunistic foraging behavior, feeding on non-conspecific abundant prey such as crustaceans when available, and switching to a high level of conspecific predation in poor waters.     

Bigeye tuna (Thunnus obesus) vertical movements in the Azores Islands determined with pop-up satellite archival tags

Movement patterns of 17 bigeye tuna (Thunnus obesus) near the Azores Islands were analyzed between April and May 2001 and 2002 using pop‐up satellite archival tags. Despite short attachment durations (1 to 21 days, 8.2 days on average), their vertical movements revealed much shallower distribution of bigeye tuna in comparison with previous studies in the tropical Pacific and tropical Atlantic. Depth and temperature histograms were unimodal, although overall depth distribution during the day was deeper than during the night due to daily incursions in deeper waters. Although generalized additive models showed significant non‐linear relationships with weight of the fish and sea level anomaly (as a proxy for variability of thermocline depth), the effect of these variables on bigeye depth appeared minor, suggesting that vertical movements of bigeye in the Azores during the spring migration may be influenced by food availability in upper water layers.     

稳定性二氧化氯改善斑节对虾育苗水环境效果的试验

使用稳定性二氧化氯(S.ClO_2)处理斑节对虾育苗水体(实验室规模),测定其水化学指标以及用S.ClO_2预处理育苗用水,测定ClO_2在不同光照条件下消减情况。试验结果表明:①质量浓度0.35×10~(-6)mg/L的S.ClO_2在露天强光条件下,可在2 d内完全消减;②S.ClO_2可降低水中的COD、氨氮和亚硝酸盐氮的含量,COD、氨氮和亚硝酸盐氮降低最大幅度分别为12.9%、58.9%、25.0%;③S.ClO_2对水中DO无明显影响。     

武汉市普通居住小区户外园林景观现状分析与探讨

笔者通过对武汉市普通居民小区进行了论述访问调研,对武汉市居住小区户外环境现状作了简单的阐述和分析,同时提出了对武汉市居民小区景观规划设计设想,为武汉市城市普通居民小区园林景观设计与管理提供一定的设计参考。     

剖析吕家村城乡一体化建设中景观环境规划

通过对吕家村城乡一体化建设规划中景观环境规划的阐述,透析通过城乡一体化建设来加快村庄内造林绿化工作步伐,同时牢固树立"环境意识"和"资源意识",加大农村村庄环境建设,加大对村容村貌的整治,提高吕家村的绿化率,提升吕家村的村镇品味,改善农村生活环境,改善局部小气候,带动天水旅游产业的发展。     

植物景观对商业步行街生态环境的影响

商业步行街建筑物林立,人流密集,装饰材料挥发大量有害污染物,流动的人群消耗O2,释放CO2,且步行街空气流动不畅,因此,商业步行街的空气质量较差。商业步行街植物景观不但具有净化空气,维持碳氧平衡和吸收有害气体等积极的生态效益,而且商业步行街良好的植物景观设计,可为其带来更可观的商机。所以,注重植物景观的设计将会成为商业步行街建设的发展趋势。     

大房郢水库浮游生物群落结构变化与环境因子关系研究

为了更好地了解合肥市饮用水源地水生态环境状况,于2020年夏季、秋季、冬季及2021年春季对大房郢水库的水质、浮游植物和浮游动物进行监测,对比浮游生物群落现存量与历史变化,并使用冗余分析（RDA）以及蒙特卡洛置换检验探究环境因子对浮游生物群落的影响。结果表明,研究区域浮游植物以蓝藻门为主要优势种属,密度及生物量较2005年分别增加37.7%和7.0%,浮游动物以桡足类为主要优势种,密度较2005年大幅度下降了77.5%,生物量多样性增加了47.8%,影响浮游生物群落结构的主要环境因子为NH3-N、T（温度）、pH和TN。此外,研究也揭示了季节变化对水库浮游生物的物种组成影响小,但对浮游生物的丰度及多样性影响显著。