Automated data analysis to rapidly derive and communicate ecological insights from satellite-tag data: A case study of reintroduced red kites

Analysis of satellite-telemetry data mostly occurs long after it has been collected, due to the time and effort needed to collate and interpret such material. Delayed reporting reduces the usefulness of such data for nature conservation where timely information about animal movements is required. To counter this problem, we present a novel approach which combines automated analysis of satellite-telemetry data with rapid communication of insights derived from such data. A relatively simple algorithm (based on radial and angular velocity calculated from fixes) allowed instantaneous detection of excursions away from settlement areas and automated calculation of home ranges on the remaining data. Automating the detection of both excursions and home-range calculations enabled us to disseminate ecological insights from satellite-tag data instantaneously through a dedicated web portal. The automated analysis, interpretation, and communication of satellite-tag and other ecological data offer clear benefits to nature conservation research and practice.     

上海北侧区域海陆风对污染物扩散的影响

利用数值模拟方法研究了上海北侧区域海陆风对污染物扩散的影响,包括上海城郊-崇明岛-启东市区及这三区域之间的北支水道与南支水道.使用当量法表征太阳辐射和长波辐射引起的近地面空气热量变化,模拟结果与ECMWF再分析数据呈现较好的一致性.结果表明,在海风阶段,宽海(南支水道)、窄海(北支水道)区域都能形成海风,前者较后者发生...     

流域非点源水污染排放清单估算系统构建

基于流域水质改善与水环境管理需求,结合目前流域非点源水污染排放存在的问题,本研究采用SOA-B/S架构,运用MVC6和GIS与环境模型集成关键技术,构建流域非点源水污染排放清单估算系统,并系统梳理了地形数据、污染源环境统计数据、气象数据等基础信息,采用基于输出系数法的非点源水污染负荷估算模型,实现了对全年及年内各分水期非点源水污染排放清单的处理分析和估算。系统通过数据库、GIS平台、模型集成和业务系统建设,实现了对不同时间和空间尺度下不同地区的非点源水污染负荷估算,推进了流域非点源污染排放的信息化、科学化及可视化管理,为决策者制定流域水环境管理措施和方案提供了有力的技术支持。     

Estimating the complexity of bird song by using capture-recapture approaches from community ecology

Repertoire size, the number of unique song or syllable types in the repertoire, is a widely used measure of song complexity in birds, but it is difficult to calculate this exactly in species with large repertoires. A new method of repertoire size estimation applies species richness estimation procedures from community ecology, but such capture-recapture approaches have not been much tested. Here, we establish standardized sampling schemes and estimation procedures using capture-recapture models for syllable repertoires from 18 bird species, and suggest how these may be used to tackle problems of repertoire estimation. Different models, with different assumptions regarding the heterogeneity of the use of syllable types, performed best for different species with different song organizations. For most species, models assuming heterogeneous probability of occurrence of syllables (so-called detection probability) were selected due to the presence of both rare and frequent syllables. Capture-recapture estimates of syllable repertoire size from our small sample did not differ significantly from previous estimates using larger samples of count data. However, the enumeration of syllables in 15 songs yielded significantly lower estimates than previous reports. Hence, heterogeneity in detection probability of syllables should be addressed when estimating repertoire size. This is neglected using simple enumeration procedures, but is taken into account when repertoire size is estimated by appropriate capture-recapture models adjusted for species-specific song organization characteristics. We suggest that such approaches, in combination with standardized sampling, should be applied in species with potentially large repertoire size. On the other hand, in species with small repertoire size and homogenous syllable usage, enumerations may be satisfactory. Although researchers often use repertoire size as a measure of song complexity, listeners to songs are unlikely to count entire repertoires and they may rely on other cues, such as syllable detection probability.Communicated by A. Cockburn     

An entitlement approach to the challenges of mangrove management in El Salvador

This paper summarizes those factors that have contributed to the degradation of the mangroves in El Salvador, and examines the implications of proposed changes in property rights to the mangroves for poor coastal communities. Current patterns of extraction and conversion in the mangrove ecosystem in El Salvador can be viewed through an entitlement lens that confers property right upon some actors, for certain uses, and denies them to others. Unfortunately, the present system of laws and regulations that governs resource use in the mangroves is contradictory and confusing. A number of laws currently are active that give entirely different directives about the use and transformation of the ecosystem. The rational and sustainable management of the mangroves cannot be secured without a redefinition of entitlement rights. This redefinition of entitlements, however, should take into account the needs of those whose livelihoods are intimately connected to the health of the ecosystem.     

No evidence for a critical salinity threshold for growth and reproduction in the freshwater snail Physa acuta

The growth and reproduction of the freshwater snail Physa acuta (Gastropoda: Physidae) were measured at various salinity levels (growth: distilled water, 50, 100, 500, 1000 and 5000 microS/cm; reproduction: deionized water, 100, 500, 1000 and 3000 microS/cm) established using the artificial sea salt, Ocean Nature. This was done to examine the assumption that there is no direct effect of salinity on freshwater animals until a threshold, beyond which sub-lethal effects, such as reduction in growth and reproduction, will occur. Growth of P. acuta was maximal in terms of live and dry mass at salinity levels 500-1000 microS/cm. The number of eggs produced per snail per day was maximal between 100 and 1000 microS/cm. Results show that rather than a threshold response to salinity, small rises in salinity (from low levels) can produce increased growth and reproduction until a maximum is reached. Beyond this salinity, further increases result in a decrease in growth and reproduction. Studies on the growth of freshwater invertebrates and fish have generally shown a similar lack of a threshold response. The implications for assessing the effects of salinisation on freshwater organisms need to be further considered.     

The ecological and economic potential of carbon sequestration in forests: examples from South America

Costs of reforestation projects determine their competitiveness with alternative measures to mitigate rising atmospheric CO2 concentrations. We quantify carbon sequestration in above-ground biomass and soils of plantation forests and secondary forests in two countries in South America-Ecuador and Argentina-and calculate costs of temporary carbon sequestration. Costs per temporary certified emission reduction unit vary between 0.1 and 2.7 USD Mg(-1) CO2 and mainly depend on opportunity costs, site suitability, discount rates, and certification costs. In Ecuador, secondary forests are a feasible and cost-efficient alternative, whereas in Argentina reforestation on highly suitable land is relatively cheap. Our results can be used to design cost-effective sink projects and to negotiate fair carbon prices for landowners.     

Système planctonique et pollution urbaine: un aspect des populations zooplanctoniques

Zooplankton populations of a marine area exposed to pollution from the sewage outfall of Marseille-Cortiou have been studied in relation to their horizontal distribution related to distance from the outfall. Samples were collected by various means, and confirmed preliminary results which had indicated that some species tend to cluster in a facies characteristic of a polluted environment. The zone in immediate proximity to the outfall is the most turbid zone; it is extremely poor in fauna but not azoic. Outside this zone and up to 500 m distance from the sewage outlet into the sea, the most euryoecious species (e.g. Acartia clausi, Oithona nana, Euterpina acutifrons, and Oikopleuridae) are frequently present. An intermediate zone then occurs, in which, together with the species mentioned above, other species quite tolerant to pollution (e.g. Clausocalanus spp., Centropages typicus, Paracalanus spp., Candacia armata and some Corycaeidae and Oncaeidae) are well represented. Outside this zone, the zooplanktonic populations show a better defined and more stable structure. Paracalanus spp. are still very abundant, together with Fritillaridae, and fish eggs and larvae. Beneath the turbid surface zone, the impact of pollution seems less marked, and an homogenous zooplankton assemblage is found whose composition is identical to that of species inhabiting unpolluted areas.

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avec la participation du Groupe EPOPEM (Equipe de Pollution Pélagique de Marseille)     

Eulerian sampling of zooplankton from Marseilles' Vieux Port over a 24 h period

A 24 h continuous study of hydrological parameters and zooplanktonic populations was carried out in Marseilles' Vieux-Port, a semi-closed area supposed to be a fairly homogeneous body of water. Sampling was performed in spring 1980 with a pump system. Samples were taken every 30 min over a period of 24 h, during which time only slight temperature variations were recorded (min.=14.5°C, max.=15.1°C); salinities were high and fairly stable (min.=37.49, max.=37.63%.). It can thus be assumed that the water was homogeneous. Concentrations of suspended particulate matter were high and fairly stable (x = 11.8 mg 1^-1). In most samples, nitrate levels were fairly low (x = 0.84 g-at 1^-1); conversely, phosphate contents fluctuated greatly (min.=0.24 g-at 1^-1, max.=2.24 g-at 1^-1). As a result of these fluctuating nutrient-salt values, the N:P ratios were often unbalanced (between 0.5 and 2.0). Detergent values were low (often less than 0.2 ppm). Zooplanktonic populations were made up of a few eurybiotic species, the most thriving of which were the cladoceran Podon polyphemoides and the copepod Acartia clausi. These two species perform nychthemeral migrations towards the surface: P. polyphemoides during the day and A. clausi at night. As a result of these opposite patterns of migrations, the planktonic biomass remained fairly stable near the surface. There were also some meroplanktonic species (especially cirripede larvae) and a small number of other copepods present. This study revealed a regular hydrological and faunal cycle with a return to initial conditions at the end of the 24 h period.