多环芳烃类污染物在部分水体中的分布及其降解途径

本文综述了水体中多环芳烃(PAHs)对水生动物及其他水生生物的危害,分析了我国城市污水、地表水、地下水和海水等部分水体中PAHs污染现状,简要阐述了水体中PAHs的存在形式及降解途径,并展望了PAHs今后的研究方向。     

渤海中部海域低氧区的发生记录

2014年8月对渤海中部海域的水文(温度、盐度)、化学(溶解氧DO、营养盐和化学耗氧量COD)和生物要素(叶绿素a Chl-a)的空间分布进行了调查。研究了该海域底层水体低氧(DO<3.0 mg/L)的分布特征,深入分析了低氧区发生的关键因素。结果显示,底层水体DO浓度最小值为2.30 mg/L,低氧面积达1200 km2,呈西北–东南走向。调查海域的西部和西南海域呈现出明显的温度层化,尤其在低氧区附近形成了一个表层与底层水体温度差(δT)>5℃的区域,δT 最高值达到7.3℃。水体密度层化与温度层化特征相似,在低氧区附近形成了一个底表层密度差(δρ)>2 g/L的等值线闭合圈。温度层化是低氧产生的主要物理因素。表层水体 COD 高值区主要分布在调查海域的西部,覆盖大部分的低氧海域。表层水体中的Chl-a(>4μg/L)和PO43--P (>6μg/L)浓度高值区主要分布在调查海域的西南部,部分与低氧区重合。本研究可为探索渤海海域富营养化演变过程提供借鉴。     

噬菌蛭弧菌的研究及应用⑤噬菌蛭弧菌微生物生态制剂在淡水水生动物养殖中的应用

淡水水生动物是指能生活在含盐量低于3‰的水体中,系统发生过程中未曾脱离水体生活的一级水生动物。我国的淡水水生动物资源非常丰富,加上人工养殖的水产品,市场供应充足。特别是淡水鱼类,世界上现有约10000种,我国就有1000种左右。随着我国经济建设的高速发展及农业结构的调整     

论长江野生濒危水生动物的遗传种质保护

长江是我国第1大河,世界第3大河。由于生态环境的破坏,长江流域野生濒危水生动物数量逐年增加。我国目前在水生动物的保护方面进行了2项工作:一是建立水生动物自然保护区,二是建立水生动物遗传基因库。随着分子生物学的发展,对濒危水生动物物种的保护,人们已经开始采用最新的方法和措施,如克隆、移植和转基因技术、干细胞技术以及基因组研究技术等。提出了长江野生濒危水生动物遗传种质保护应加强的工作。     

养殖水体部分化学因子对水产养殖影响实例及防治对策

张家港市自2004年开始开展水生动物病害测报工作,其主要内容包括水体水质现场分析和水生动物病害测报两个方面。经多年测报观察与分析,我们发现水产养殖水体中某些化学因子对水生动物生长和病害发生有较大的影响,它们甚至可使水产养殖造成重大的损失。现针对近几年来我们在监测水产养殖水体     

对鱼类经口给药应该注意的问题

正渔药是针对生活在水体中的水生动物使用的。例如为了治疗鱼类的一些细菌性疾病,就需要对鱼类口服给予抗生素类渔药。对水生动物进行口服给药,药物需要拌和在饲料中投到水体中,在这种情况下饲料中的药物或多或少地会受到水体环境和给药方式等因素的影响。如养殖水体的水温和p H等均会影响到水产用兽药的用药效果。当人们对水产养殖动物口服给药时,还会受到作为水产用兽药     

多环芳烃对水生动物毒性效应的研究进展

多环芳烃(PAHs)是广泛存在于水体环境中的一类持久性有机污染物,因其具有致癌、致畸和致突变性而备受关注。本文简述了PAHs的定义、分类、来源及其污染现状,并综述了PAHs在水生生物体内蓄积、代谢规律及其对水生生物的毒性效应:在急性毒性层面综述了PAHs对不同水生动物的毒性程度及急性致死效应;在亚急性及慢性毒性层面分别从分子水平、生理生化酶水平、细胞组织水平,综述了:PAHs暴露对水生生物的分子毒性,导致DNA单链断裂、PAHs-DNA加合物的形成;PAHs暴露对水生生物抗氧化酶系统(SOD、CAT、GPx、GSH/GSSG)、外源性有机污染物代谢酶(EROD、GST)活力的影响;PAHs暴露引起的氧化应激、脂质过氧化、组织病理学变化等氧化损伤。本综述目的是便于今后更深入地研究PAHs对水生动物的毒性效应和毒性作用机制,进而更好的控制PAHs污染,保护水生生物和水生生态环境。     

维生素C缺乏对水生动物生长性能的影响

维生素C是水生动物必须的营养物质,维生素C缺乏,对水生动物的组织器官和细胞结构均产生影响。本文综述了水生动物维生素C缺乏症、病理变化缺乏症以及导致维生素C缺乏的因素等方面的研究进展。     

水产养殖病害预测预报

9月份是夏末秋初时期,是水生动物疾病的高发季节.一方面,由于昼夜温差逐渐增加,上下水层对流加大,水中污染物沉积,为病原体滋生创造了条件;另一方面,此阶段水温适宜水生动物生长,投饵量大,水质变化快,单位水体载鱼量增加,而养殖空间有限,因此造成了水生动物机体免疫力有所下降.同时,沿海地区台风、雷雨等自然灾害时有发生,给养殖生产造成了较大威胁.为此,各地仍要高度重视水生动物疾病防控以及自然灾害对养殖生产的影响,尽最大可能减少因病害发生造成的经济损失.     

重金属对水生动物毒性的研究进展（一）

从水生动物对重金属吸收，重金属在水生动物体内的蓄积，分布规律，重金属对水生动物的毒害作用，重金属对水生动物的中毒剂量及其影响因素，重金属在水生动物体内的解毒机理等方面的研究进展开综述。     

Effect of organic fertilizer on heterotrophs and autotrophs: implications for water quality management

Alfalfa meal as a source of organic fertilizer was used in a series of pond, enclosure and laboratory experiments to determine its effect on bacteria, algae and water quality. Bacteria and flagellate algae were increased, whereas nonflagellate algae were not significantly affected by organic loadings. Bacterial and algal turnover rates we re 1.9-2.7 times daily and 0.18-0.22 times daily at 20-25^oC, respectively. Oxygen consumption rates were enhanced by increasing organic input or temperature. Dissolved oxygen in ponds with organic fertilizer was significantly lower than that in ponds without organic input. Because of low N and P content and high oxygen consumption, organic fertilizer alone is unlikely to provide adequate nutrients for algae and sufficient oxygen for fish. To stimulate the growth of food organisms for fish in aquaculture ponds, a combined use of inorganic and organic fertilizer is recommended, but the amount of organic fertilizer should be determined with care to avoid water quality deterioration. The amount of 10mg alfalfa 1^?1 wk^?1 is considered the upper safety limit for organic fertilization. The nitrogen and phosphorus ratio should be kept weekly at 20:1 by weight to promote the development of food organisms in ponds.     

Limnology of Macrobrachium amazonicum grow‐out ponds subject to high inflow of nutrient‐rich water and different stocking and harvest management

We evaluated the water characteristics and particle sedimentation in Macrobrachium amazonicum (Heller 1862) grow‐out ponds supplied with a high inflow of nutrient‐rich water. Prawns were subject to different stocking and harvesting strategies: upper‐graded juveniles, lower‐graded juveniles, non‐graded juveniles+selective harvesting and traditional farming (non‐grading juveniles and total harvest only). Dissolved oxygen, afternoon N‐ammonia and N‐nitrate and soluble orthophosphate were lower in the ponds in comparison with inflow water through the rearing cycle. Ponds stocked with the upper population fraction of graded prawns showed higher turbidity, total suspended solids and total Kjeldahl nitrogen than the remaining treatments. An increase in the chemical oxygen demand:biochemical oxygen demand ratio from inlet (4.9) to pond (7.1–8.0) waters indicated a non‐readily biodegradable fraction enhancement in ponds. The sedimentation mean rate ranged from 0.08 to 0.16 mm day^?1 and sediment contained >80% of organic matter. The major factors affecting pond ecosystem dynamic were the organic load (due to primary production and feed addition) and bioturbation caused by stocking larger animals. Data suggest that M. amazonicum grow‐out in ponds subjected to a high inflow of nutrient‐rich water produce changes in the water properties, huge accumulation of organic sediment at the pond bottom and non‐readily biodegradable material in the water column. However, the water quality remains suitable for aquaculture purposes. Therefore, nutrient‐rich waters, when available, may represent a source of unpaid nutrients, which may be incorporated into economically valued biomass if managed properly.     

大气CO2水平升高对微藻影响的研究进展

大气CO₂浓度升高将干扰水体的碳酸盐缓冲系统,导致水体pH值下降,对水生微藻产生一定的影响。文章从生长状况、光合作用、藻细胞化学元素组成和群落结构4方面分别综述大气CO₂浓度升高对海洋微藻和淡水微藻的影响。在生长方面,大气CO₂浓度升高不仅会影响某些海洋微藻和淡水微藻的生长速率,还会使某些藻细胞的形态发生变化。在光合作用方面,大气CO₂浓度升高可能会减弱微藻对CCM机制的依赖性;对不具有CCM机制的微藻来说,CO₂浓度增加可能会减弱其碳限制程度,有利于微藻光合作用。在藻细胞化学元素组成方面,大气CO₂浓度的升高对微藻细胞化学元素组成的影响与藻类的生长是否受营养盐限制有关,只有当藻类生长受到水体营养盐浓度限制时,CO₂浓度升高才会显著改变其元素组成。在群落结构方面,当微藻个体发生变化时,微藻种群间的竞争优势也会发生改变,体积较小的微藻可能将从全球CO₂水平升高的趋势中受益更多。在间接因素温度导致的水生环境变化的条件下,可能更有利于蓝藻生长,使其拥有更大的竞争优势。微藻群落结构的改变,对整个海洋生态系统和淡水生态系统都可能会造成严重的影响。最后展望了在全球大气CO₂水平升高的背景下微藻响应机制方面研究方向。     

低氧胁迫对鲻幼鱼生长、能量代谢和氧化应激的影响

为研究低氧胁迫对鲻幼鱼生长、能量代谢和氧化应激的影响,实验将其放在溶解氧(DO,mean±SE)含量分别控制在(1.66±0.41)、(4.35±0.53)、(7.03±0.36)mg/L的条件下养殖10 d,然后恢复至接近饱和溶解氧含量7.0 mg/L的条件下养殖30 d,研究其特定生长率、排氨率、耗氧率、氧氮比和血浆、肌肉、肝脏及鳃组织的总抗氧化能力(T-AOC)、过氧化物歧化酶(SOD)活力、抗超氧阴离子活力(ASOR)、丙二醛(MDA)含量、乳酸(LD)含量、总谷胱甘肽(T-GSH)、还原型谷胱甘肽(GSH)和氧化型谷胱甘肽(GSSG)含量。结果表明:低氧胁迫对鲻幼鱼的生长、能量代谢影响显著,较严重缺氧组鲻的体质量、特定生长率(SGR)、耗氧率和排氨率显著低于其他处理,不具有补偿生长的能力;而轻微缺氧组获得完全补偿生长。低氧胁迫对鲻氧化应激指标影响显著,胁迫结束时鲻通过提高某些抗氧化酶的活力来增强抗氧化能力,以提高其应对恢复正常溶解氧环境可能带来的氧化应激的能力,同时在恢复溶氧后鲻氧化应激反应也较强烈。在恢复溶解氧阶段,肝脏中GSH显著增加,说明鲻体内的保护机制被激活。肝脏和鳃中MDA的含量在低氧胁迫后与溶解氧含量呈明显的负相关性,在复氧30 d后仍然高于对照组,表明低氧胁迫加强鲻肝脏和鳃组织脂质过氧化反应。     

海水桡足类的营养及在鱼、虾、蟹幼体培育中的应用

海水桡足类在海洋食物网和生态系统中具有重要的地位,是各种海洋经济鱼类和甲壳类的重要饵料,也是经济水产动物人工育苗阶段的优质活饵料源。研究海水桡足类营养和应用效果,对提高海水鱼、虾、蟹类幼体变态率、成活率、苗种质量和育苗成功率具有重要的意义。     

Environmental effects of a marine fish farm of gilthead seabream (Sparus aurata) in the NW Mediterranean Sea on water column and sediment

This study examined the effects of organic enrichment on water column, sediments and macrofauna caused by a fish farm in the Mediterranean Sea. Samples were collected on four sampling campaigns over a one‐year cycle. Significant differences were found in the water column in dissolved oxygen, dissolved inorganic nitrogen, phosphate and total phosphorus concentrations between the fish farm and the control. The increase in the dissolved inorganic nitrogen and phosphate concentrations at the fish farm modified the stoichiometric ratios between nutrients, with silicate acting as limiting nutrient at the fish farm 11% more than at the control. Nevertheless, chlorophyll a concentration in the water column was higher at the control station, probably due to the fouling of the underwater fish farm structures. Significant differences were found in sediment concentrations of organic matter, total phosphorus and redox potential between the fish farm and the control. The Canonical Correlation Analysis indicated that organic matter, total phosphorus, redox potential and% of gravels accounted for 68.9% of the total variance in the species data. Changes were observed in macrofauna, with a decrease in number of species and up to a nine‐fold increase in abundance with respect to the control.     

Impacts of Burrowing Ghost Shrimp, Genus Lepidophthalmus Crustacea: Decapoda: Thalassinidea, on Penaeid Shrimp Culture

Abstract The burrowing ghost shrimp Lepidophthalmus sinuensis Lemaitre and Rodrigues and Lepidophthalmus bocourd (A. Milne Edwards) have significant impacts on pond-based culture of penaeid shrimp. Marked abbreviation of the larval cycle, an adaptation for estuarine retention in wild populations, favors accumulation of recruits into the same substrates as the parental population where densities of these burrowers sometimes exceed 650 individuals/m². Higher densities of burrowing shrimp appear to correlate with lower yields of penaeid shrimp because of oxygen requirements by the thalassinids and also bioturbation effects. Rich sources of organic materials in highly reduced pond substrates can be readily exploited by Lepidophthalmus species due to their physiological adaptations to low oxygen concentrations. Bioturbation and ventilatory movement of water through burrowed sediments by ghost shrimp move reduced nutrients into the water column with potential toxic effects on penaeids. Ultimately, activities of these estuarine burrowers oxidize benthic sediments and cycle nutrients into the water column, the negative impacts of which are probably restricted to aquaculture settings.     

Effect of environmental factors,especially hypoxia and typhoons,on recruitment of the gazami crab <Emphasis Type="Italic">Portunus trituberculatus</Emphasis> in Osaka Bay,Japan

Important crustacean fisheries occur in semi-enclosed seas. These fisheries can be strongly affected by intense exploitation and episodic anthropogenic and climatic events, but the effects of such events remain largely uninvestigated. To assess the influence of such factors, we examined dredge catch data on the gazami crab Portunus trituberculatus in Osaka Bay, Japan from 1984 to 2008 and investigated various associated environmental factors. There were five peak monthly catches during the study period, which typically occurred in August or November. Relative abundance (measured as catch per unit effort) in August was positively associated with previous recruitments to the fishery, typhoon frequency, and dissolved oxygen saturation during the juvenile period. In comparison, relative abundance in November was strongly correlated with the number of typhoons and was also positively associated with dissolved oxygen levels in the bottom water. The results of our multi-decadal study suggest that hypoxia is a principal agent of mortality for juvenile crabs and that normoxia in the nursery habitats is a necessary condition for the successful recruitment of individuals into the adult population. The positive influence of typhoons on recruitment is probably due increased mixing in stratified coastal waters, which disrupts the persistent hypoxia in bottom waters, but other unknown processes may also contribute to favorable recruitments.     

The nutrient status of the agriculturally impacted Gamtoos Estuary,South Africa,with special reference to the river‐estuarine interface region (REI)

• 1. Ecological water reserves are part of the new water management philosophy in South Africa. The estuaries are threatened by excessive water abstraction from their rivers and the consequent reduction in freshwater input. This study was conducted to further improve our understanding of freshwater requirements in terms of nutrients for South African estuaries.
• 2. The Gamtoos Estuary was sampled between November 1996 and November 1998 to determine its nutrient status and freshwater input rates. Furthermore, the possible existence of a distinct river‐estuarine interface (REI) in terms of nutrients has been investigated. Nutrients analysed included phosphate, nitrate, nitrite, ammonia, dissolved organic nitrogen (DON), dissolved organic carbon (DOC), particulate organic nitrogen (PON) as Kjieldahl nitrogen, total particulate phosphorus and total particulate carbon.
• 3. The Gamtoos River was found not to be the ultimate source of nutrients to the estuary, but non‐point sources such as the seepage of fertilisers from adjacent agricultural fields determined to a great extent the nutrient status of the estuary.
• 4. Results showed that it was not possible to identify a defined river‐estuarine interface region for all nutrients. Most were measured in higher concentrations in the lower salinity reaches (<17‰) where we observed the combined effect of inputs from the Gamtoos River, an agricultural drainage pipe, and fertilizer seepage from non‐point sources on nutrient concentration.
• 5. Prolonged water withdrawal for human use impacts the continuous renewal of the nutrient pool so important to other South African estuaries with relative pristine catchment areas. However, reduced fresh water inputs could enhance eutrophication in polluted estuaries due to a decreased flushing potential of the estuary. In this case the Gamtoos Estuary has a freshwater requirement for freshets and floods to “clean” the estuary of accumulated nutrients and other organic material.
• 6. This should be a consideration in further freshwater abstraction policies. Conservation issues arise since the Gamtoos Estuary is one of the few permanently open estuaries along the South African coast and serve in this study as an example and as a first attempt to relate freshwater requirements to nutrient dynamics in a South African context.

Copyright © 2002 John Wiley & Sons, Ltd.     

The use of high rate algal ponds for the treatment of marine effluent from a recirculating fish rearing system

A high rate algal pond (HRAP) system was used to treat effluent from a recirculating sea water aquaculture system in southern France. Dicentrarchus labrax L. were farmed at a high density, with effluents containing an average of 10 mg L^?1 dissolved inorganic nitrogen (DIN) and 1.3 mg L^?1 reactive phosphorus (RP). On a yearly basis, the algal pond removed 59% of the dissolved nitrogen and 56% of the phosphorus input, which was converted into 3.3 kg DW m^?2 algae. Green macroalgae were dominant throughout the year and the algal biomass mirrored the seasonal changes in daily irradiance and temperature. This first year study supports the possibility of treating marine aquaculture wastes using HPAPs, although conditions will have to be found to mitigate the strong influence of climate on the algal community during winter. During the more temperate season, only 150 m² of treatment ponds would be necessary to remove the nutrients produced by 1 ton of fish. Treated water was characterized by a high pH, elevated levels of dissolved oxygen (midday value) and low concentrations of nutrients and suspended solids. The absence of toxic phytoplankton meant that the water could be recycled through the farm tanks.