南沙群岛电子地图及其多媒体模式研究

近十年来随着高新技术发展应运而生的电子地图,具有信息丰富、直观易读、更新方便、使用灵活等优点。本文对南沙群岛中多国领土之争的大片航行危险区与他国非法侵占地、且自然条件复杂与调研程度不断深入的地区,进行了制作电子地图的科学依据和实际意义的论述。同时指出电子地图多媒体在该海域应用的前景与作用。     

浙南岛屿潮间带蟹类的区系特点

作者根据１９９０—１９９７历年对浙南岛屿潮间带生态调查所获的材料,分析了该地区蟹类的区系特点。经整理鉴定计蟹类９７种,隶属于１２科５６属,其中软相７０种、硬相３２种,硬、软相皆有出现的为５种。该地区蟹类区系以亚热带暖水性种类占优势,其次为暖温带性种类,属印度──西太平洋区系区的中国──日本亚区。蟹类的组成与分布受到海流、底质、潮汐等综合因素的影响。     

南沙群岛海域沉积物间隙水营养盐（氮、磷、硅）的研究

通过1997年11月和1999年7月2个航次对南沙群岛海域的现场调查,实测了南沙群岛深海盆沉积物的孔隙度?间隙水的营养盐含量,估算了沉积物海水界面营养盐的扩散通量?2个航次的沉积物间隙水的NO2-N,NO3-N ,NH4-N,PO4-P ,SiO3-Si含量,1997年冬季航次平均为4.68,43.84,115.68 ,6.85,425.71μmol·L-1,1999年夏季航次(H4SiO4除外)平均为2.72,36.86,31.40,10.10μmol·L-1;平均扩散通量,1997年冬季航次为0.03,-14.07,121.70,0.25,72.54μmol·m-2·d -1,1999年夏季航次(H4SiO4除外)为0.10,-11.74,40.47,-0.56μmol·m-2·d -1?NH 4和H4SiO4 是扩散量最大的2种组分,而HPO2-4 和NO-2的扩散量极小?     

Crustal contamination and fluid/rock interaction in the carbonatites of Fuerteventura (Canary Islands, Spain): a C, O, H isotope study

Fuerteventura—the second largest of the Canary Islands consists of Mesozoic sediments, submarine volcanic rocks, dike swarms and plutons of the Basal Complex, and younger subaerial basaltic and trachytic series. Carbonatites are found in two Basal Complex exposures: the Betancuria Massif in the central part of the island and the Esquinzo area in the north. values of the carbonatites increase progressively from south to north of the island. This phenomenon is attributed to different degrees of assimilation of sedimentary carbonate. Homogeneous, typically magmatic values for carbonatites which have preserved primary igneous textures and minerals suggest a well-mixed reservoir where changes in values result from the storage of carbonate magmas at different structural levels. The magma storage allowed assimilation of sediment to varying degrees before final emplacement of carbonatites. Shifts in towards more positive and negative values from presumed primary compositions are observed in the carbonatites. On the basis of the oxygen isotope compositions of calcite, mica and K-feldspar, and the hydrogen isotope compositions of micas, the changes in the values of the carbonatites can be related to fluid/rock interactions.     

南沙渚碧礁生态系有机碳的分布及周日变化特征

1999 年 4 月对我国南沙群岛渚碧礁海水中溶解有机碳的分布及礁坪区颗粒有机碳 (POC) 和溶解有机碳 (DOC) 的周日变化特征进行了观测。结果表明,渚碧礁表层海水 DOC 变化范围为 1.43~3.62 mg/L,平均为 2.16 mg/L,含量分布大致表现为礁坪区>潟湖>礁外。潟湖 DOC 的垂直分布大致表现为表层高于底层,可能与表层浮游植物的光合作用有关。礁坪区 POC 及 DOC 都呈现显著的周日变化特征,POC 呈现夜晚高,白天低的特点,浮游植物的昼夜垂直移动可能是产生该现象的主要原因。DOC 的周日变化则主要受浮游动物昼夜垂直移动及细菌等生物活动的影响。     

Participatory artisanal fisheries management in islands: Application to the Canary Islands (Spain)

Socio-economic development of small-island fishing communities is greatly dependent on local coastal and marine resources. However, illegal fishing and aggressive practices in insular ecosystems lead to over-exploitation and environmental deterioration. Moreover, a lack of scientific data increases uncertainty and prevents the adequate monitoring of marine resources. This paper focuses on the integration of local fishing communities into decision-making processes with the aim of promoting artisanal fishing on the Island of Tenerife (the Canary Islands), as a way to preserve the marine ecosystem and socio-economic development of traditional cofradias (fishers' organisations). A qualitative methodological framework, based on participatory problem-solution trees and focus groups, was used to identify the main factors impeding the sustainable development of the artisanal fishing sector on the island and to elaborate collective proposals with policy implications. The fishing community involved identified four main issues that are maintaining an unsustainable island fishery: 1) Over-exploitation; 2) Poor self-management of cofradias and commercialisation problems; 3) Fisher individualism and low co-management strategies, and 4) Illegal fishing increase vs. artisanal fishing decline. Results show the required policy enhancements to tackle them and the need to adapt regulations to the local situation.     

Abergasilus amplexus Hewitt, 1978 (Ergasilidae: Copepoda) from New Zealand,with a description of the male

The male of Abergasilus amplexus Hewitt, 1978 is described for the first time. Previous records of A. amplexus are discussed and a new locality, Te Whanga Lagoon, Chatham Islands, is reported.     

Probabilistic risk assessment of common booster biocides in surface waters of the harbours of Gran Canaria (Spain)

The presence of booster biocides in the aquatic environment has been associated with a risk to non-target species due to their proven toxicity. The aim of the present study was to determine the spatial and temporal distribution of common booster biocides in different harbours of the island of Gran Canaria (Spain) and evaluate, by means of a probabilistic risk assessment (PRA), the ecological risk posed by these compounds. With these objectives, a monitoring campaign was conducted between January 2008 and May 2009, collecting a total of 182 seawater samples. Four common booster biocides (TCMTB, diuron, Irgarol 1051 and dichlofluanid) were monitored. Diuron levels ranged between 2.3 and 203 ng/L and Irgarol 1051 between 2.4 and 146.5 ng/L. The ecological risk associated with these levels was always low, however, with probabilities of exceeding the 10th percentile of autotroph toxicity below 3.5%.     

Contemporary 14C radiocarbon levels of oxygenated polybrominated diphenyl ethers (O-PBDEs) isolated in sponge-cyanobacteria associations

Considerable debate surrounds the sources of oxygenated polybrominated diphenyl ethers (O-PBDEs) in wildlife as to whether they are naturally produced or result from anthropogenic industrial activities. Natural radiocarbon (¹⁴C) abundance has proven to be a powerful tool to address this problem as recently biosynthesized compounds contain contemporary (i.e. modern) amounts of atmospheric radiocarbon; whereas industrial chemicals, mostly produced from fossil fuels, contain no detectable ¹⁴C. However, few compounds isolated from organisms have been analyzed for their radiocarbon content. To provide a baseline, we analyzed the ¹⁴C content of four O-PBDEs. These compounds, 6-OH-BDE47, 2′-OH-BDE68, 2′,6-diOH-BDE159, and a recently identified compound, 2′-MeO-6-OH-BDE120, were isolated from the tropical marine sponges Dysidea granulosa and Lendenfeldia dendyi. The modern radiocarbon content of their chemical structures (i.e. diphenyl ethers, C₁₂H₂₂O) indicates that they are naturally produced. This adds to a growing baseline on, at least, the sources of these unusual compounds.