Study on the potential of suspended longline mariculture of the scallop Chlamys farreri in offshore areas

The growth and survival of the scallop Chlamys farreri exposed to different initial densities were evaluated in culture systems from inshore and offshore areas of Sungo Bay, China, from May 2007 to March 2008. Water quality data (e.g. temperature, salinity, current speed, chlorophyll a and total particulate material) were measured concurrently. The C. farreri reached the market size after 10 months of cultivation. Average survival rates for the same initial densities were lower in the inshore area than those in the offshore area. Survival rates also were inversely proportional to the initial densities. Scallops in offshore area with initial densities of 20 and 30 individuals per disc resulted in significantly greater shell heights, soft tissue weights and muscle weight compared with the other experimental groups. Tissue weight increased rapidly from May to September. However, scallops in offshore area had a second growth peak during October to November. Scallops in the offshore area had higher growth and survival rates, which may be attributed to high water current speed resulting in increased food supplies. Results indicate that the scallop C. farreri has an aquaculture potential in offshore cultivation systems.     

基于宏基因组学的中国沿海密集养殖水域秋季底质细菌多样性研究

近年来,随着海水养殖业的迅猛发展,我国沿海水域生态系统遭受了不同程度的污染。选取我国沿海10个典型养殖水域(大连、唐山、蓬莱、连云港、启东、象山、宁德、东山,湛江、陵水),并以美济礁水域作为对照组(无水产养殖活动),采用宏基因组denovo测序方法系统分析了这些水域微生物的多样性,并进行了对比研究。结果发现,我国典型养殖水域微生物多样性与非养殖水域(美济礁)相比差异较大,美济礁水域微生物多样性明显低于各养殖水域;不同的养殖水域之间,微生物的丰度和多样性亦存在较大的差别;厚壁菌门和变形菌门是这些水域丰度最大的门类,其中厚壁菌门中的芽孢杆菌是其优势菌种。研究结果不仅有助于了解中国沿海典型养殖水域微生物的多样性,并可为评估我国海洋生态系统的污染水平提供基础数据。     

三种植物精油对美人鱼发光杆菌美人鱼亚种的抑菌效果及其毒力基因表达的影响

为研究百里香精油、牛至精油和肉桂精油对海水养殖重要致病菌美人鱼发光杆菌美人鱼亚种（Photobacterium damselae subsp．damselae,PDD）的抑菌作用,采用二倍稀释法分别测定3种植物精油对6株不同致病力PDD菌株的最小抑菌质量浓度（MIC）和最小杀菌质量浓度（MBC）。采用分光光度计法检测添加精油后6株PDD生长曲线的变化;以2株高致病性PDD菌株为研究对象,分析不同浓度精油对PDD毒力基因表达量及胞外产物（extracellular products,ECP）活性的影响;分析了3种精油存储不同时间后以及在金属离子影响下的药效稳定性。结果显示,这3种精油对6株PDD菌株均具有较好的抑菌及杀菌作用,MIC为32～128 μg/mL,MBC为64～192 μg/mL;3种精油对2株高致病性PDD菌株的毒力基因表达及ECP的磷脂酶活性和溶血活性均有抑制作用,其中低浓度精油对PDD主要毒力基因的抑制作用最明显。3种精油于室温下避光存储35 d,对实验菌株的杀菌率均大于99%,显示其良好的药物稳定性;水环境中不同浓度Na+、Mg2+、Ca2+、K+等对3种精油的杀菌效果无明显影响。研究表明,3种精油均适宜开发为防治水产动物细菌性疾病的新型渔药或饲料添加剂。本研究可为拓展芳香类植物精油在水产疾病防控上的应用提供借鉴与参考。     

河北省海水养殖区水质的时空变化特征

海水养殖是河北省水产业重要的支柱产业。为了保护河北省海水养殖区的生态环境,实现海水养殖业可持续发展,根据2000—2010年的监测数据,采用模糊综合评价法和单因子污染指数法对海水养殖区水质的时空变化特征和质量状况进行了研究与评价。结果表明：近年来河北省海水养殖区水质逐步有所好转,其中秦皇岛市、唐山市附近海水养殖区水质基本可以满足养殖用水的要求,黄骅市附近海水养殖区的水质污染较重,已不能满足养殖用水的要求;河北省海水养殖区水体中主要污染物是磷酸盐（PO34--P）、无机氮（DIN）,其次为铅（Pb）和汞（Hg）。     

海水养殖动物营养生态学研究及其养殖可持续发展

在阐述海水养殖动物营养生态学的概念、研究意义、主要研究内容及其方法的基础上,概述了海水养殖动物营养生态学现状及发展对策,最后简要论述了海水养殖动物营养生态学研究及其养殖可持续发展的关系,以期为今后开展相关研究积累基础资料。     

Profile of a fishery collapse: why mariculture failed to save the large yellow croaker

The large yellow croaker (Larimichthys crocea), endemic to East Asia was once one of the three top commercial marine fishes of China PR. Heavily exploited since the 1950s, wild stocks were so severely depleted by the 1980s that most individuals subsequently sold originated from hatcheries. After peaking at about 200 000 tonnes in the mid‐1970s, catches of the croaker in China PR declined by over 90% within just 2 decades; according to most decline criteria this would categorize the croaker as “threatened” and management measures, including restocking, were developed. The extensive government‐sponsored mariculture program introduced to address food supply and overfishing in the 1980s, particularly of the croaker, was one of the earliest for marine finfish, not only in China PR, a nation with a rich and highly successful history in aquaculture, but globally. In this first, in‐depth, profile of a key fishery and early mariculture development, we integrate ecological and biological information with the fishing, management, mariculture and economic history to trace the collapse of wild stocks and assess why management and mariculture did not result in wild stock recovery. Evidence strongly suggests that a combination of heavy exploitation of spawning and over‐wintering aggregations, poor management and overfishing pressure were major factors in stock declines, with contributions from pollution, habitat degradation and marine ecosystem shift. Although the croaker proved a highly successful mariculture candidate, with approximately 70 000 tonnes produced in 2005, the highest of any marine fish cultured in China PR, mariculture and restocking have failed to restore croaker stocks and may have, inadvertently, led to biodiversity losses. The detailed history of the croaker is a sobering reminder that successful mariculture, albeit important for food production and livelihoods, is not necessarily a solution to overfishing, and moreover, may have compromised fishery recovery by competing for funds, attention, space, and maybe genetic resources.     

Growth rate differences between four Chilean populations of edible seaweed Chondracanthus chamissoi (Rhodophyta,Gigartinales)

The effects of temperature, photon flux density and photoperiod on the growth rate of female gametophytic and tetrasporophytic thalli of Chondracanthus chamissoi from four populations along the Chilean coast were studied in vitro. Both reproductive phases survived and grew under all the conditions tested, with growth rates varying between 0.1 and 7.5% day^?1. The results showed higher growth rates with increases in temperature and photon flux density levels. The growth rate was higher in female gametophytic thalli in almost all treatments. The photoperiod did not cause significant differences in the growth rate for either reproductive phases in any of the populations studied. Temperature was the principal factor affecting the growth rate of C. chamissoi.     

海水对虾工厂化循环水养殖系统模式分析

对虾养殖由于受到水资源和虾病的困扰,工厂化循环水养殖已经成为今后对虾养殖的一个重要方向。对虾工厂化循环水养殖系统的结构包括了养虾池、水处理技术、消毒杀菌、增氧技术、水温调节装置等。目前,典型的养殖模式有美国德州跑道式对虾养殖系统、台南室内自动化循环水养虾系统、美国佛罗里达三阶段养殖系统和美国夏威夷基于微藻的循环水对虾养殖系统。文中对这4种典型的对虾工厂化循环水养殖系统的养殖试验情况进行分析比较。     

海水养殖鱼哈维弧菌分离株的耐药谱型分析

为了解和分析南海沿岸地区临床分离的哈维弧菌(Vibrio harveyi)菌株耐药谱多样性,采用K-B法对84株哈维弧菌分离株进行了12种抗生素的敏感性实验,并通过聚类分析对分离菌株耐药性进行研究,探讨其抗生素耐药性同菌株时空分布的关系。实验结果显示,84株哈维弧菌的耐药谱型数量为26种,谱型丰富度为31.0%;多重耐药谱型数量(耐药种数3种以上)为13种,占总耐药谱型数量的50.0%,谱型丰富度达59.1%。海南、广东、广西、福建的分离株分别包含有18种、15种、3种、1种耐药谱型,4个地区均具有J型(FUR/AMO)耐药谱;2007―2012年各年份菌株耐药谱型为:2007年2种(J、M,耐2种抗生素)、2010年4种(A、B、J、M,耐5种抗生素)、2011年24种(除Y、Z外的A-X耐药谱型,耐7种抗生素),2012年26种(包括Y、Z耐药谱型,耐8种抗生素)。聚类分析将实验菌株分为i~vi共6个亚群,进而聚类为Group I、Group II两个组群;各亚群菌株具有独特的耐药谱型,耐药谱型分别是N、P、T、U、Y(i亚群),R、S(ii亚群),K、P(iii亚群),F、H、O、X、V、W(iv亚群),E、G、Q(v亚群),C、L、Z(vi亚群);两个组群菌株没有共同的耐药谱型。研究结果表明,哈维弧菌分离株耐药谱型多样,谱型丰富度较高,来源不同的菌株耐药谱型存在差异,聚类分析方法能够根据耐药性情况有效地对菌株分型。     

Mortality,hematology, and histopathology of common snook Centropomus undecimalis (Perciformes: Centropomidae) exposed to acute toxicity of ammonia

This study aimed to evaluate the tolerance of common snook Centropomus undecimalis larvae and juveniles exposed to acute concentrations of un-ionized ammonia for 96 h at 35g L^?1 salinity, after 24 h starvation. For that, 10 larvae (20.85 ± 1.46 mm) of 47 days post hatch (DPH) per experimental unit (1.5 L) were exposed to 0.00 ± 0.00, 0.65 ± 0.04, 1.29 ± 0.09, 2.59 ± 0.18, 3.88 ± 0.27, 5.17 ± 0.34, and 6.47 ± 0.43 mg L^?1 NH₃, in triplicates, at 26.72 ± 0.08°C, dissolved oxygen at 5.72 ± 0.10 mg L^?1 and pH 8.45 ± 0.06. During this period, no mortalities were observed. Another trial was performed with five juveniles (20.35 ± 6.10 g, 13.90 ± 1.75 cm) per experimental unit (60 L) exposed to 0.00 ± 0.00, 2.26 ± 0.07, 2.68 ± 0.11, 3.20 ± 0.13, 3.68 ± 0.17, and 4.27 ± 0.16 mg L^?1 NH₃, in triplicates, at 21.90 ± 0.76°C, dissolved oxygen at 6.27 ± 0.21 mg L^?1 and pH at 8.38 ± 0.04. Fish mortality increased as ammonia concentrations increased at each day, and LC₅₀ 96 h was 3.52 mg L^?1 NH₃. Larvae were less sensitive than juveniles, demonstrating that the environmental toxicity of ammonia to common snook is influenced by age. Sublethal exposition to ammonia caused histological damages in gills of common snook juveniles and variation on glucose levels, hematocrit, and red blood cells number, showing negative effects on fish homeostasis. Moreover, compared to other species, the common snook has great resistance to ammonia.