Integrated spatial health assessment of yellow perch (<Emphasis Type="Italic">Perca flavescens</Emphasis>) populations from the St. Lawrence River,Quebec, Canada) part A: physiological parameters and pathogen assessment

A multi-disciplinary approach was used to evaluate the health of yellow perch (Perca flavescens) in the St. Lawrence River (Quebec, Canada), which is experiencing a severe population decline in the downstream portion of the river. Physiological parameters, liver alterations, trace metal concentrations, parasite prevalence and abundance, stable isotope composition, and the presence/absence of the viral hemorragic septicemia virus (VHSV) were evaluated in perch collected at six sites along the river: Lake St. François, Lake St. Louis (north and south), Beauregard Island, and Lake St. Pierre (north and south). Trace metal concentrations in surface water were higher in Lake St. Louis and downstream of a major urban wastewater treatment plant discharge, indicating that this effluent was a significant source of Cu, As, Ag, Zn, and Cd. Levels of Pb in surface water exceeded thresholds for the protection of aquatic life in Lake St. Louis and were negatively correlated with body condition index in this lake. In Lake St. Pierre, Cu, Ag, and Cd bioaccumulated significantly in perch liver and lower body condition index and greater liver damage were observed compared to upstream sites. Parasite analyses indicated a higher abundance of metacercariae of the trematodes Apophallus brevis and Diplostomum spp. in Lake St. Louis, and VHSV was not detected in the liver of yellow perch for all studied sites. Overall, results suggested that the global health of yellow perch from Lake St. Pierre is lower compared to upstream studied sites, which could contribute to the documented population collapse at this site.     

Integrated spatial health assessment of yellow perch (Perca flavescens) populations from the St. Lawrence River (QC,Canada), part B: cellular and transcriptomic effects

Environmental Science and Pollution Research - Multi-biological level assessments have become great tools to evaluate the health of aquatic ecosystems. Using this approach, a complementary study...     

Development and Evaluation of a Multiplexed Real-Time TaqMan RT-PCR Assay with a Sample Process Control for Detection of F-specific RNA Coliphage Genogroups I and IV

There are increasing concerns of zoonotic transmission of some animal enteric viruses, such as calicivirus, hepatitis E virus, and rotavirus, which are closely related to human pathogenic strains. Most enteric viruses are detected by molecular techniques because they cannot be cultured. Surrogates such as F-RNA coliphages are cultivable but few molecular methods exist. Individual real-time TaqMan RT-PCR assays for the replicase gene of F-RNA coliphage genogroups I and IV were developed and multiplexed with a real-time TaqMan RT-PCR assay for feline calicivirus as a sample process control for the simultaneous detection and enumeration of genogroup I and IV F-RNA coliphages. Genogroup IV were successfully detected with the multiplexed assay in 80% of fecal samples that contained F-RNA coliphage levels ≥3.2 log plaque forming units (pfu). F-RNA coliphage were at or below the limit of detection in most fecal samples when levels were ≤4 log pfu/g.     

推进我国减灾事业的三个支柱

本文阐述推进我国减灾事业的3个支柱,即:(1)发挥政府的主导作用;(2)重视科学技术在减灾中的作用;(3)依靠全民的参与。     

三江平原湿地植物物种空间分异规律的探讨

研究了三江平原典型湿地在地形、水分等因素制约下的植物物种空间分异规律,包括垂直分异规律和水平分异规律。首先,按照地形和水分的分异组合特点,把湿地生境分为较干燥生境、季节积水生境和常年积水生境。然后,在各个生境内采用样方法和样线法调查植物物种。调查分为20世纪70年代、80年代和2003年3个时期,范围包括三江平原的典型湿地植物群落。数据分析时采用了生境组合法。即把3个不同的生境组合成一个水分(或地形)梯度带,根据频度和多度指标筛选出主要物种,然后按照其空间位置,列出主要植物物种沿水分梯度带的分布序列。研究发现:三江平原湿地不同生境的植物物种组合和垂直分异差别明显。较干燥生境的植被类型以岛状林群落为代表,乔木、灌木和草本植物层次分明。季节性积水生境的植被类型以小叶章群落为代表,是典型的湿草甸植物群落,垂直结构不明显。常年积水生境以毛果苔草群落为代表,植物群落层次也比较明显。植物物种水平分异规律,基本上可由植物物种空间分布序列图来代表。随着地势降低,水分增多,乔、灌植物,湿草甸植物,水生草本植物在特定的空间依次出现。     

论灾害“预防文化”

本文以现代灾害管理和系统工程的观点,论述了灾害预防文化的基础背景以及在我国建设灾害预防文化的内容。     

Laboratory rearing of the clupeid fish Harengula pensacolae from fertilized eggs

Pelagic eggs of the scaled sardine Harengula pensacolae (Goode and Bean), have been hatched and reared in the laboratory for the first time. Larvae were reared in two 75 l aquaria under constant illumination, at an average temperature of 26.2°C. Zooplankton collected in a 35 mesh net was fed to the newly hatched larvae, and the diet was supplemented later with Artemia salina nauplii and a pelleted food. Larvae hatched at 4 mm TL (total length), and metamorphosed about 25 days later at 25 to 30 mm TL. Survivors averaged 76 mm TL 100 days after hatching. Of the 500 incubated eggs, 2.8% survived until 20 days, after which no significant natural mortality occurred. Sources of natural mortality included starvation, a copepod parasite (Caligus sp.), and injuries from contact with the sides of the tank. Larvae began feeding at 4.5 mm TL on copepod nauplii averaging 62 in body width. Scaled sardines were photopositive throughout the larval stage.Contribution No. 149, Bureau of Commercial Fisheries Tropical Atlantic Biological Laboratory, Miami, Florida 33149, USA.     

Energy storage and dynamics in bay anchovy Anchoa mitchilli

The energy of the body components and the energy costs of spawning and overwintering in the bay anchovy Anchoa mitchilli, the most abundant fish in Chesapeake Bay, were studied to determine seasonal variability during the different stages of its life cycle. Bimonthly samples were collected by trawl from April 1990 through October 1991. Fish condition and body energy levels fluctuated seasonally, and were related to anchovy size. Energy equivalents (cal g^-1 dry wt) was highest in December, before the overwintering period. The somatic weight component increased by 32 to 33% and total body weight by 26% during the spawning season, indicating that feeding not only met energy requirements of daily spawning but also provided surplus energy for growth. The overwintering loss of energy was 33 to 35% of total body calories, and was primarily derived from deposit fat in somatic and visceral tissues.     

Food concentration and stocking density effects on survival and growth of laboratory-reared larvae of bay anchovy Anchoa mitchilli and lined sole Achirus lineatus

Bay anchovy (Anchoa mitchilli) eggs were stocked at densities from 0.5 to 32.0 l^-1 and larvae were fed on wild plankton (copepod nauplii) in concentrations that ranged from 50 to 5000 prey l^-1. Lined sole (Achirus lineatus) eggs were stocked at 0.5 to 16.0 l^-1 and larvae were fed wild plankton at concentrations from 50 to 1000 prey l^-1. Some larvae of each species survived at all stock and food levels to the transformation stage at 16 days after hatching. Survival rates for both species exceeded 40% when food concentration was 1000 l^-1 or higher. Growth and dry weight yields also increased significantly at the higher food concentrations. Effects of initial stocking density were not well defined, but both survival and growth decreased at the highest stocking rates. Standardized culture of bay anchovy and lined sole larvae can be based on a food concentration of 1000 copepod nauplii l^-1 to routinely produce healthy larvae.     

论保险业在减灾中的作用

灾害对生命财产造成巨大损失。在充满灾害风险的环境中,保险不仅是灾后补偿灾害损失的一种有效措施,而且能在灾前通过保险费率的厘定在土地利用、区域规划、结构加固等方面起到减轻灾害的控制作用。因此保险业是减灾工作中的重要力量。