Hunnebotn: a seawater basin transformed by natural and anthropogenic processes

The lake Hunnebotn (A=1 km², z_max=11 m) has become separated from the sea by isostasis, but a 1.5-m-deep channel is held open by periodic dredging. Water exchange is minor due to the small tidal range (21 cm) and the length of the channel (1.8 km), but there may be an inflow of seawater at spring tides. The terrestrial watershed runoff may be fertilized by sewage and agricultural runoff despite some measures taken to prevent this. Historical and new records of biological communities indicate variations in sensitivity to different phases of the isolation and eutrophication process. The native oyster was most sensitive and disappeared first. Later, the eelgrass disappeared possibly due to overgrowth by epiphytic algae, and finally there was a massive littoral–sublittoral invasion of green algae. The lake should not be left in this condition, for aesthetic reasons and because marine inlets and eutrophic brackish water may serve as refugia for spore populations of toxic microalgae. Improving surface water quality will require better control of anthropogenic sources, but bursts and leaks of nutrients from the anoxic monimolimnion cannot be controlled.     

Stratigraphy of the sediment infill in Bosphorus Strait: water exchange between the Black and Mediterranean Seas during the last glacial Holocene

The sediment infill over the Paleozoic bedrock in the Bosphorus Strait consists of four sedimentary units which were deposited in the last 26,000 ¹⁴C years B.P. The stratigraphy of these units suggests that this part of the Bosphorus was a freshwater lake between 26,000 and 5,300 ¹⁴C years B.P., depositing sands with a freshwater mollusc fauna of Black Sea neo-euxinian affinity (Dreissena rostriformis, Dreissena polymorpha, and Monodacna pontica). The first appearance of euryhaline Mediterranean molluscs (e.g., Ostrea edulis, Mytilus edulis) was observed at 5,300 ¹⁴C years B.P. in this part of the Bosphorus. Deposition of coarse Mytilus-bank and Ostrea-bank units suggests that the establishment of the present dual-flow regime in the Bosphorus took place at about 4,400 ¹⁴C years B.P.     

环境污染物萘、蒽、菲、芘的好氧微生物降解

多环芳烃（PAHs）是环境污染物，具有致癌性和致突变性。选取香港米埔红树林淤泥富集微生物，研究红树林微生物对PAHs的好氧降解。试验观察到，萘、蒽、菲、芘在液体培养条件下均有较强的挥发性。多底物培养液中的菌群浓度明显高于单底物系统。多次连续转接使培养液中的细菌生长能力增强。初始底物浓度可影响细菌生长速率，底物浓度过低或过高均不利于细菌生长。从分离得到的降解菌中选取豚鼠气单胞菌Aeromonascaviae WⅡ和斑点气单胞菌Aeromonas punctata TⅡ进行单菌降解试验，结果表明，豚鼠气单胞菌WⅡ能够高效降解4种底物，而斑点气单胞菌TⅡ能够高效降解萘、蒽和芘3种底物。另外还发现斑点气单胞菌TⅡ能够明显降低水中菲的挥发速度。     

Radioecological studies of activation products released from a nuclear power plant into the marine environment

The seaweeds Fucus vesiculosus, Fucus serratus, Ascophyllum nodosum and Cladophora glomerata and crustaceans of the Idothea and Gammarus families have proven to be excellent bioindicators for radioactive corrosion products released from a nuclear power plant into the marine environment. These bioindicators have been used to map the spatial and temporal distribution of the released radioactivity. The activity has been followed up to 150 km from the power plant, and the decrease in activity concentration C(z) in the bioindicators with distance z can be expressed by a power function C(z) = α. z^?1·4 where α is a constant.The variation with time of activity concentration very well reflects the amount of activity discharged from the power plant, with surprisingly good resolution in time.The bioindicators exhibit different uptake patterns of the radionuclides detected, and variations from summer to winter for the crustaceans Idothea, when compared to Fucus, has been found.     

Multi-proxy evidence of long-term changes in ecosystem structure in a Danish marine estuary, linked to increased nutrient loading

This paper presents a study of changes in eutrophication over the past 100 years in a fertile estuary. The Danish estuary Mariager Fjord is a long, narrow sill-fjord with a permanently anoxic basin. In 1997 anoxia spread from the basin to the entire inner estuary, killing almost all eukaryotes and prompting debate on the causes. This paper reports a multi-proxy survey of ²¹⁰Pb-dated sediment cores from the anoxic basin. Analyses of diatoms, dinoflagellates, pigments and geochemical proxies were used to determine changes in ecosystem structure over the past 100 years. The aim was to establish ‘base-line conditions’, for management purposes, of the biological structure prior to 1900, and to examine possible causes of changes observed. Geochemical proxies total nitrogen (TN), total carbon (TC) and biogenic silica (BSi) were consistently high throughout the sediment record. Increased concentrations of pigments and natural isotopes (δ¹³C, δ¹⁵N) suggested increasing production and nutrient loading. The main changes in the biological proxies occurred between 1915 and the 1940s, and indicated that the estuary has been somewhat eutrophic since 1900, but that the eutrophication process increased over the past 100 years. A reconstruction of TN concentration by a diatom-based transfer function supports this interpretation, with inferred TN ca. 1900 around 60 μmol l⁻¹, and an increase in TN concentration over the past century to ca. 130 μmol l⁻¹ by 1995. Inferred TN decreased to ca. 100 μmol l⁻¹ by 2001, similar to present day monitoring data.     

南四湖湖内浅槽工程施工对水环境的影响及控制措施

南四湖湖内工程是沂沭泗河洪水东调南下续建工程的单项工程,工程区位于山东省省级自然保护区内;挖泥船施工将对湖内水环境产生一定影响。本文从排泥场回水污染物、生产废水和生活污水三个方面阐述了工程施工对水环境的影响程度,并且提出了相应的控制措施。     

中国对虾镰刀菌病的细胞病理研究

本文报导中国对虾养成期病原体茄类镰刀菌Fusarium solani(Mart)的细微结构及其引起宿主的细胞病理变化,以便为该病的正确诊断和有效防治提供依据。     

ASM1中污水水质参数与化学计量系数的估测

简要介绍了活性污泥1号模型中14个污水水质参数与5个化学计量系数的估测方法和典型取值。     

饵料对中间球海胆生长发育的影响初探

实验结果表明 :单独投喂牟氏角毛藻或与三角褐指藻、绿色巴夫藻混投 ,中间球海胆幼虫成活率最高 ,其生长速度也最快 ,中间球海胆稚幼海胆培育的最好饵料是前期投喂的石莼等薄嫩的海藻 ,后期投喂海带其生长速度最快     

Vertical Sound Velocity Transition in the Coral Reef Core and Its Significance of Indicating Facies

On the basis of the sound velocity measurements of the coral reef core from Nanyong No.1 well of Yongshu Reef in the Nansha Islands,the paper studies the relations between the vertical sound velocity transition features in the coral reef core and the corresponding stratigraphic depositional facies change as well as stratigraphic gap of erosion,analyses the cause of the sound velocity transition,expounds the concrete process of the sea level change resulting in the stratigraphic gap of erosion and facies change in the coral reef and explains the relations between the vertical sound velocity transition in the coral reef core and the corresponding stratigraphic paleoclimate and the sea level change.This study is of important practical value and theoretical significance to the island and reef engineering construction and the acoustic logging for oil exploration in the reef limestone area as well as the paleoceanographic study of the marginal sea in the westerm Pacific Ocean.