Understanding the role of chronic environmental disturbance in the context of island biogeographic theory

Island biogeographic theory offers a powerful conceptual framework for understanding and managing insular diversity. The human impact on insular environments is constantly growing, especially because of tourism. We performed a simulation study aimed at improving the understanding of the role of disturbance in islands. We also built an individual-oriented computer model of an archipelago subjected to chronic disturbance of varying degree. Results are discussed in the light of island biogeographic theory. Relevant results show the importance of autoecological characteristics of the species considered, regarding the attainment of equilibrium and the species-area relationship in both disturbed and undisturbed cases. The possibility of bias in the predictions of the equilibrium model is pointed out. Fundamental criticisms concerning the ecological relevance of the equilibrium theory are discussed.     

Evaluation of Organochlorine Compounds (PCDDs,PCDFs, PCBs and DDTs) in Two Raptor Species Inhabiting a Mediterranean Island in Spain (8 pp)

Background Species that are at high levels of the food web have often been used as bioindicators to evaluate the presence of persistent contaminants in ecosystems. Most of these species are long-lived, so pollutant burdens may be integrated in some complex way over time. This makes them particularly sensitive to deleterious effects of Persistent Organic Pollutants (POPs). Birds have been suggested as useful organisms for monitoring pollutant levels. Traditionally such studies have been carried out with raptors such as osprey (Pandion haliaetus), peregrine falcon (Falco peregrinus), bald eagle (Haliaetus leucocephalus), etc. In this paper we present the results of a monitoring study conducted on two raptor species, osprey (Pandion haliaetus) and red kite (Milvus milvus), inhabiting a Mediterranean island (Menorca, Spain). These two species have different feeding habits; ospreys prey on fish and red kites feed on terrestrial species. This study constitutes a good opportunity to investigate if differences in feeding habits (aquatic vs. terrestrial) influences the contaminants pattern in two species inhabiting the same area. Methods The study was conducted in a non-destructive way, using only failed eggs, to avoid the damage of the population stability. Eggs were collected during the period 1994–2000. The contaminants examined were dichlorodiphenyltrichloroethanes (DDTs, including DDT and its main metabolite, DDE), polychlorinated biphenyls (PCBs), including ortho PCBs (PCBs with at least one Chlorine atom in the ortho position): #28, 52, 95, 101, 123+149, 118, 114, 153, 132+105, 138, 167, 156, 157, 180, 170, 189, 194; and non ortho PCBs (PCBs with no Chlorine atom in the ortho position): #77, 126, 169 and all the polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) with Chlorine atoms at the 2,3,7 and 8 position (2,3,7,8-substituted PCDDs and PCDFs). The analysis of organochlorine compounds was performed using a sample treatment based on a Solid Phase Matrix Dispersion procedure. Ortho PCBs and DDTs were determined by HRGC-μECD; non ortho PCBs and PCDD/Fs were determined by HRGC-HRMS. Results and Discussion The sum of the ortho PCB congeners analysed ranged from 0.94 to 15.03 μg/g wet weight (ww) for ospreys and from 1.0 to 11.2 μg/g ww for red kites. In both species, PCB congeners #153, #138 and #180 accounted about 75% to total ortho PCB concentrations. Regarding non ortho PCBs, for ospreys, concentrations ranged from 0.16 to 1.39 ng/g wet weight (ww) and for red kites from 0.12 to 0.51 ng/g ww, being congener #126 the most abundant. Concerning DDTs, concentration for ospreys ranged from 0.07 to 1.03 μg/g ww; and for red kites ranged from 0.90 to 2.10 μg/g ww, representing DDE more than 95% of the total DDTs, which proves a past use of DDT in the study area. Differences in contaminant levels between species are probably associated to feeding habits. The fish-eating species presents the highest PCB levels, whereas the terrestrial species exhibits the highest DDT levels. PCDD/Fs in ospreys were in the range 2.6–14.2 pg/g ww, while in red kites the range was slightly wider (22.2–43.2 pg/g ww), being PCDDs the major contributors in black kites. Ospreys had PCDDs similar to PCDF concentrations. PCDD/F profiles were mostly influenced by OCDD in both species. Non ortho PCBs were the major contributors to calculated Toxic Equivalent Quantity (TEQs) in both species. Conclusion In both species studied, ortho-PCBs could represent a problem of concern since 57% of the eggs exhibited levels higher than 4 μg/g ww, reported as the level that could cause reduced hatchability, embryo mortality, and deformities in birds. Recommendations and Outlook Results found in this study suggest that a more detailed study to clear up possible deleterious effects of PCBs on the bird populations studied here should be done. Section Editor: Prof. Dr. Paola Gramatica (paola.gramatica@uninsubria.it)     

城市热岛效应的研究模型

城市热岛不但影响城市气候，而且严重影响城市的大气环境，城市发展的多样性决定了城市热岛的复杂性、研究模型的多样性。本文通过对城市热岛常用的研究模型进行了分析、比较，为城市热岛研究模型的选择和进一步研究城市热岛的机理以及城市热岛对城市环境的影响提供了参考依据。     

人工浮岛在丁香湖水质改善中的应用

针对丁香湖水体恶化产生蓝藻的问题,在湖中设置人工浮岛对水质进行改善,浮岛植物以凤眼莲为主,辅以美人蕉等搭配.人工浮岛运行后,对水体中TN、TP指标净化效果良好,TN的去除率为48.1%～52.1%,TP的去除率为55.0%～64.4%,而且具有一定的景观效果.     

舟山饮用水源中铁锰污染及其成因分析

根据2008年8月到2009年12月对浙江省舟山本岛与普陀山岛的饮用水源的水质监测数据,分析了舟山饮用水源中铁、锰污染特征,并结合各类饮用水源的本身特性,探讨了铁、锰超标成因.结果表明:舟山水库与河流中铁、锰浓度在6～11月较高,铁、锰浓度超标主要发生在9～11月.个别水库中铁、锰浓度在夏季呈现明显的垂直分布规律.舟山...     

Seasonality of spawning by tropical anguillid eels around Sulawesi Island, Indonesia

Remarkably little is known about the life histories of the many tropical anguillid eels distributed across the Indo-Pacific region, and since the Danish expedition to study eels in the region in 1928 and 1929, research on these eels has only begun again in recent years. Sampling for anguillid leptocephali in the Indonesian Seas has been carried out recently to learn about the spawning ecology and larval distributions of tropical eels there. The leptocephali of Anguilla marmorata, Anguilla bicolor pacifica, Anguilla borneensis, Anguilla interioris, and Anguilla celebesensis were collected around Sulawesi Island both in May 2001 and October of 2002. The development of genetic identification techniques has enabled these leptocephali to be identified to species, and their distributions and sizes during different seasons indicated that there are differing life history patterns among sympatric species in the region. A. celebesensis was found to have been spawning in Tomini Bay of northeastern Sulawesi Island in March and April 2001, but apparently, no spawning had occurred in the late summer and fall of 2002. Studies on anguillid glass eels have suggested that tropical anguillids may spawn throughout much of year, but our research on leptocephali in Tomini Bay and data on the downstream migration of tropical anguillids in the major tributary to Tomini Bay indicate that A. celebesensis may have a distinct seasonal pattern of spawning possibly related to the regional monsoon cycles. This is the first evidence of seasonality of spawning in tropical anguillid eels whose life histories are only just beginning to be revealed.     

长兴岛陆源排污总量控制

根据长兴岛规划布局,设定三种排污口排海方案.在此基础上,基于海洋环境容量的基本理论,对各种排放方案的COD、无机氮和活性磷酸盐允许排放量进行预测计算.计算结果将为长兴岛临港工业区排污口方案优化和排海污染物总量控制规划编制提供科学依据.     

海南岛北部潮间带红树林对重金属的累积特征

对海南岛北部潮间带红树林湿地7种红树植物（根、茎、叶）及其根系沉积物中重金属元素含量进行了分析,结果表明：研究区湿地沉积物中Ni、Cu、Zn、As和Cd的变异系数大于0.50,沉积物中重金属分布很不稳定。其中Cr、Cu、Zn、As和Cd的含量均高于海南水系沉积物背景值,可能存在外源的输入。仅有Pb的含量略低于海南水系沉积物背景值。总体来看,大部分植物显示了对Cd元素的较强的富集能力（BAC〉1）,瓶花木对重金属元素的吸收能力总体上要比其他红树植物强一些,木果楝对重金属元素的吸收能力总体上最弱。其中,瓶花木（Scyphiphora hydrophyllacea）对Cr、Zn、As和Cd的吸收能力较强,莲叶桐（Hernandia sonora）对Cr和Ni的吸收能力较强,角果木（Ceriops tagal）对Pb的富集能力较强。角果木（Ceriops tagal）和桐花树（Aegiceras corniculatum）对Cd和Pb的运输能力较强,瓶花木（Scyphiphora hydrophyllacea）对Cu、Zn和Cd的运输能力较强,尖瓣海莲（Bruguiera sexangula）对Cr、Ni、Cd和Pb的运输能力较强,木榄（Bruguiera gymnorrhiza）对Ni、Cu、Cd和Pb的运输能力较强,木果楝（Xylocarpus granatum）对Cr、Zn和Cd的运输能力较强,莲叶桐（Hernandia sonora）对Cr也有较强的运输能力。但此次所研究的红树植物对As元素的运输能力均很弱,建议适量引入适宜在研究区生长并且对As元素富集能力较强的植物。     

Liver and renal histopathology of North Atlantic long-finned pilot whales (Globicephala melas) contaminated with heavy metals and organochlorine compounds

Long-finned pilot whales (Globicephala melas) from the Faroe Islands are known to be heavily polluted with contaminants, such as mercury (Hg) and organochlorine compounds (OC). This is postulated to exert adverse health effects on whales as well as the human population who rely on its meat and blubber as food sources. It was therefore decided to conduct a screening pilot study to determine contaminant concentrations and histopathology of liver and renal tissues in a total of 14 specimens from this subpopulation. In blubber, the mean ∑OC concentration was 31,887 ng g^?1 lw (range: 18,170–47,425 ng g^?1 lw) of which ∑PCB concentration was 23,416 ng g^?1 lw (range: 13,947–34,543 ng g^?1 lw; n = 3). In liver, mean Hg concentration was 138 µg^?1 ww (range: 54–351 µg g^?1 ww; n = 7) and mean cadmium (Cd) concentration 15 µg g^?1 ww (range: 7–31 µg g^?1 ww; n = 7). In the kidney, the mean Cd concentration was 36 µg g^?1 ww (range: 23–47 µg g^?1 ww; n = 7). Of the liver Hg concentrations, two were at the suggested toxic threshold levels of 60 µg g^?1 ww and five were 2–6-fold above. Liver selenium (Se) : Hg was on average 1.11 (range: 0.97–1.41; n = 7) indicating that Se was in excess, which decreased the risk of acute Hg poisoning. Histopathological examinations showed high prevalence (>35%) of renal glomerular arteriosclerosis, glomerular capillary dilatation, dilatation and hyalinization of Bowman's space/capsule and tubular hyaline casts. In liver tissue, high prevalence was found for portal cell infiltrates, lipid granulomas, hepatocytic lipid accumulation, bile duct proliferation, lipid-filled Ito cells, and focal necrosis. In a single juvenile male, 4 of 8 renal and 3 of 7 liver lesions were present. Cadmium concentrations increased significantly in the presence of glomerular arteriosclerosis and a similar trend was found for tubular hyaline casts. Based on these findings, as well as the nature of the lesions, data indicate that the histopathological changes were a result of age and that contaminants are likely to be the co-factors in the development in at least three renal and four liver lesions.     

海南岛东部陆架表层沉积物重金属污染评价

对海南岛东部陆架29个站位的表层沉积物重金属元素(Cu、Cr、As、Pb、Zn和Cd)进行了含量测试及分布特征分析,采用地累积指数(I_geo)、富集因子(EF)和潜在生态危害指数对其进行了评价.研究结果表明:重金属含量空间分布趋势较为相似,呈现出由陆向海略微减小的趋势.6种重金属元素可能有相同或相似的来源,但Pb和As受到了人类活动影响.以上地壳和海南岛近岸未受污染沉积物为背景值的I_geo和EF值排序有所不同.研究区单项潜在生态危害系数平均值排序为Cd> As> Cu> Pb> Cr> Zn,Cu、Cr、Pb和Zn等4种重金属为轻微潜在生态危害,As和Cd在个别站位达到了中等潜在生态危害水平.综合潜在生态危害指数评价结果显示,研究区绝大多数站位处于轻微潜在生态危害水平.潜在生态危害水平相对较高的区域邻近万泉河、陵水河和三亚河河口.