Effects of salinity on endogenous rhythm of the Manila clam, Ruditapes philippinarum (Bivalvia: Veneridae)

The Manila clam Ruditapes philippinarum, an intertidal bivalve, was exposed to different salinity regimes (from 31.0–31.7‰ down to 20‰, 15‰, 10‰, 5‰), and the endogenous rhythm in its oxygen consumption was studied using an automatic intermittent-flow respirometer. When exposed to salinities reduced from 31.5‰ to 20‰ and 15‰ under otherwise constant conditions, the clams recovered a clear endogenous circatidal rhythm in their oxygen-consumption rate after having dampened periods of 12 h and 48 h, respectively. At salinities less than 10‰, however, the oxygen-consumption rate was depressed greatly at the beginning of the experiment for about 36 h and then increased to a level higher than normal, but the rhythm of oxygen consumption was not recovered. The results of this study indicate that the Manila clam, a euryhaline organism, cannot maintain a normal metabolic activity at a salinity lower than 15‰. All clams were dead after exposure at a salinity of 5‰ for 7 days. Received: 28 February 2000 / Accepted: 26 August 2000     

建立我国生态环境标准体系的初步构想

我国的生态环境标准极其薄弱，建立生态环境标准体系是我国生态环境保护的迫切需要。借鉴我国目前针对污染防治的环境标准体系，提出了我国生态环境标准体系的基本框架，以及生态环境标准制订的原则和重点。     

生态气象监测评估业务平台的设计与应用

  针对目前生态气象监测轨道业务的特点，结合工作的实际需要，运用C和C++语言建立了生态气象监测评估业务平台。在程序设计中，采用了生成中间交换文件的结构组织，能够对各模块的输出结果进行详尽直观的分析，并提供了等值线色斑图与区域填充等多种图形绘制方式。该系统可处理AVHRR和EOS/MODIS卫星遥感资料，对气象观测报文进行解译、数据分类管理和质量控制，统计计算水体密度指数、湿润指数、植被覆盖指数、土地退化指数、灾害指数和生态质量综合评价指标，以图形、图像的形式输出生态气象监测评估产品，实现了卫星遥感与生态气象地面监测数据的有效组织和智能化管理。将系统应用于湖南省生态质量气象评价，业务化运行的结果表明，该系统具有较好的业务实用性。〖HJ1〗〖HJ〗
〖HT5”H〗     

Environmental estrogenic effects and gonadal development in wild goldfish (Carassius auratus)

Serum vitellogenin (VTG) contents of wild goldfish (Carassius auratus) were investigated as a sensitive biomarker for artificial estrogenic compounds in aquatic environments. Goldfish was sampled from a pristine area, a river situated 5 km downstream from a sewage treatment works (STW), and also from the Young-San River in Korea. The female yolk precursor protein VTG was not detected when gonadosomatic index (GSI) was less than 0.85%, while VTG levels of >10 microg/ml were found in males whose GSI was less than 1.53%. In male goldfish sampled from STW and the Young-San River, the higher VTG corresponded to lower GSI. This study suggested a trend that gonad development was connected to VTG levels in both sexes, and the application of GSI and histological analysis provide an attractive possibility that it could be included in the panel of markers used for estrogenic activity investigation of aquatic environments.     

Endogenous circatidal rhythm in the Manila clam Ruditapes philippinarum (Bivalvia: Veneridae)

Manila clams, Ruditapes philippinarum, removed from their natural environment and maintained for 9 weeks in continuously immersed conditions exhibited a clear endogenous circatidal rhythm in oxygen consumption. The clams exhibited a semidiurnal rhythmicity in oxygen consumption after showing a diurnal pattern in the first few days (5 to 7 d) of the experiment. The results of the present study indicate that activity rhythms of clams are controlled not only by exogenous factors, but also by an endogenous circatidal periodicity. Received: 8 April 1998 / Accepted: 1 February 1999     

Recovery of iron oxide and calcium chloride from an iron-rich chloride waste using calcium carbonate

Journal of Material Cycles and Waste Management - The ilmenite-chloride process has used for the production of TiCl4 from the ilmenite (FeTiO3) ore, which produces cyclone dust containing mostly...     

Effects of sudden changes in salinity on endogenous rhythms of the spotted sea bass Lateolabrax sp.

The endogenous rhythm of oxygen consumption in juvenile spotted sea bass (Lateolabrax sp.) was measured to test the effects of sudden changes in salinity on the metabolic activity. Mean oxygen consumption rates of this euryhaline fish decreased by 13.5 to 16.0% and 25.3 to 36.4% when they were transferred from 31.5 to 15‰ seawater and to fresh water (0‰), respectively. The maximum rate of oxygen consumption was observed between 18:00 and 19:00 hrs local time, 1 to 2 h before sunset, even though they were kept in constant darkness. The peaks of oxygen consumption occurred in 23.2- and 23.3-h intervals, which correspond with a circadian rhythm, as revealed by maximum entropy spectral analysis. A markedly weakened rhythm in oxygen consumption occurred from 8 to 10 d after onset of the experiments. This study indicates that spotted sea bass can withstand sudden drops in salinity from 31.5‰ to fresh water, and yet maintain a regular though somewhat dampened endogenous rhythm of oxygen consumption. Received: 16 June 1997 / Accepted: 3 February 1998     

Development of freshwater sediment management standards for organic matters, nutrients, and metals in Korea

Korean water quality managers are required to promptly develop national assessment standards for freshwater sediment quality due to the Four Major River Restoration Project in Korea in 2009. We conducted this study to develop sediment management standards (SMSs), determining obviously and severely polluted sediment, which could have adverse impacts on water quality and aquatic ecosystem. The SMSs values were derived from the 95th percentile of concentration distribution for organic matter and nutrients in sediment quality database. For the SMSs of metals, foreign sediment quality guidelines (SQGs) were adopted. As a result, 13 % for loss on ignition (LOI), 1,600 mg/kg for total phosphorus (TP), and 5,600 mg/kg for total nitrogen (TN) were set as the SMSs for freshwater sediment in Korea. These values were higher than the range of heavily polluted sediment from USEPA Region 5 guideline derived by the similar approaches for the Great Lakes harbor sediments, and similar or lower than the severe effect level (SEL) from provincial sediment quality guideline (PSQG) of Ontario, Canada by screening level concentration (SLC) approach. However, SMSs in the present study are appropriate considering the concentration ranges and the Korean SMSs’ definition for freshwater sediments in Korea. The Puget Sound marine sediment cleanup screening level (CSL) in Washington State, USA were adopted as the Korean SMSs for As (93 mg/kg), Cd (6.7 mg/kg), Cr (270 mg/kg), Cu (390 mg/kg), Pb (530 mg/kg), and Zn (960 mg/kg) in freshwater sediments. Hg concentration (0.59 mg/kg) of CSL was too low to determine the polluted freshwater sediments in Korea, and the SEL of Ontario, Canada for mercury concentration (2 mg/kg) was selected as the SMS for Hg. These values were found reasonable through the assessment of applicability with the datasets from locations directly affected by obvious point sources. These results indicate that SMSs for organic matter, nutrient, and metals derived within the present study can successfully determine obviously and severely polluted sediment in Korea. However, the SMSs have limits to specifically determine the effects of polluted sediment on water quality and aquatic ecosystem in Korea. Thus, we will revise and specify SMSs considering those effects and further sediment quality assessment framework in the near future.     

江西武夷成矿带铜多金属矿产资源远景评价与展望

华南武夷山地区处于扬子、华夏两大构造单元交接叠加地段,构造变形复杂,中生代岩浆活动强烈,具有十分优越的成矿条件,矿产资源潜力巨大.本文以正在武夷山成矿带开展的矿产远景调查工作和资源评价工作所取得的阶段性成果为基础,分析了武夷山成矿带的成矿地质背景、主要矿床类型及近几年的找矿勘查成果,并对武夷成矿带江西省境内铜多金属矿产资源潜力进行了初步评价,划分了十七个找矿远景区.