Change in environmental stability and the use of resources on small islands: The case of Formentera,Balearic Islands,Spain

Since the beginning of the 1960s, mass tourism has been the most important menace to the environmental stability of fragile and vulnerable Mediterranean microinsular systems. The socioeconomic changes introduced by tourism have produced important variations in the use of resources, including land. The result usually has been an increase in the level of artificiality of the territory, particularly in coastal areas. The intensity and frequency of change in the use of resources and the induced changes in the level of artificiality may be used as an estimation of environmental stability. The northern area of Formentera, Balearic islands, Spain, being the most environmentally important area of the island and simultaneously the most threatened by mass tourism development, has been chosen as a study case. Forty types of vegetation and land use have been estimated and mapped in the area. The stability level of each land use type has been estimated, before and after the development of tourism, and the main environmental processes have been identified. An attempt is made to predict some future trends and their variations.     

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)     

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.     

崇明东滩景观格局的生态学分析与评价

在崇明岛功能区划的基础上,利用2006年的遥感影像对崇明东滩的景观类型进行解译,并对景观格局变化和植被覆盖度进行了分析与评价。结果表明:崇明东滩的景观面貌已经由原始潮滩演化出目前多达11种斑块类型。从景观空间形态指标和景观组分指标分析结果来看,崇明东滩的生境破碎化趋势已经显现,但从景观空间关系指标和Shannon均匀性指标分析结果来看,景观聚集度和连通度尚处于较高水平(分别为96.27和99.15),均匀度尚较大(0.59)。崇明东滩的植被覆盖度主要集中在0.3至0.9之间,植被覆盖度整体上尚处于较高水平。     

A 700-year record of mercury in avian eggshells of Guangjin Island, South China Sea

Ancient eggshells over the past 700 years were extracted from an ornithogenic sediment profile on Guangjin Island, South China Sea. Based on SEM and nitrogen isotope analyses, we determined that neither post-depositional processes nor seabirds’ dietary changes had a large influence on eggshell Hg levels. The historical change of Hg in these eggshells was reconstructed. Eggshell Hg was a marker for past Hg deposition in marine environment. The eggshell Hg showed three small peaks at around 1300AD, 1600 AD and 1700-1750AD and rapid increase since 1800 AD. Before 1970 AD the Hg deposition in the Xisha area had global distribution characteristics, with increased Hg emissions due to global anthropogenic activities in industrial times. However, after 1970 AD, a further sharp increase up to present day occurred, implying that the Hg production center had gradually shifted from Europe and America to Asia.     

Calibrating and monitoring the western gray whale mitigation zone and estimating acoustic transmission during a 3D seismic survey, Sakhalin Island, Russia

A 3D marine seismic survey of the Odoptu license area off northeastern Sakhalin Island, Russia, was conducted by DalMorNefteGeofizika (DMNG) on behalf of Exxon Neftegas Limited and the Sakhalin-1 consortium during mid-August through early September 2001. The key environmental issue identified in an environmental impact assessment was protection of the critically endangered western gray whale (Eschrichtius robustus), which spends the summer–fall open water period feeding off northeast Sakhalin Island in close proximity to the seismic survey area. Seismic mitigation and monitoring guidelines and recommendations were developed and implemented to reduce impacts on the feeding activity of western gray whales. Results of the acoustic monitoring program indicated that the noise monitoring and mitigation program was successful in reducing exposure of feeding western gray whales to seismic noise.