Size‐based differences in isotopic niche width (δ13C and δ15N) of green turtles (Chelonia mydas) nesting on Príncipe Island,Gulf of Guinea     

Rogrio L. Ferreira  Filipe R. Ceia  Teresa C. Borges  Jaime A. Ramos  Alan B. Bolten 《Marine Ecology》2021,42(1):e12636

Within the same population, nesting green turtles (Chelonia mydas) might exploit different niches by exhibiting polymorphic foraging strategies and/or inhabiting geographically distinct foraging areas. This is crucial information for the conservation of this species. Here, we used stable carbon and nitrogen isotope ratios (δ¹³C and δ¹⁵N) to test for differences in a population of green turtles nesting on Príncipe Island (1°37′N; 7°24?′E), Central Africa. A total of 60 nesting females were sampled on the two main nesting beaches of the island in December 2012. Minimum curved carapace length (CCL) was recorded, and δ¹³C and δ¹⁵N values were measured in the epidermis of each individual. Overall, CCL varied from 87.0 to 108.0 cm (mean ± SD =100.0 ± 5.1), δ¹³C values from ?19.4 to ?8.6‰ (?17.3 ± 1.8) and δ¹⁵N values from 7.9 to 17.3‰ (13.6 ± 1.5). Despite the large variation in both isotopic ratios, their distributions were unimodal, showing an absence of polymorphic foraging strategies and isotopically distinct foraging areas. However, smaller females (< median, 100.8 cm) occupied a much larger isotopic niche (i.e., four times greater) than larger females. These results suggest that nesting green turtles may forage opportunistically on the resources available in each of their foraging home ranges, with smaller females venturing to more isotopic‐diversified areas and/or exhibiting broader foraging strategies than larger females. In addition, and in accordance with other studies, findings suggest that the foraging grounds used by the Príncipe green turtle nesting females are distributed mainly throughout the Gulf of Guinea.  相似文献   

象山港大型底栖动物功能群研究   总被引：12，自引：3，他引：9       下载免费PDF全文

尤仲杰  陶磊  焦海峰  施慧雄  楼丹 《海洋与湖沼》2011,42(3):431-435

2006年7月-2008年8月对象山港13个站位进行了8个航次的大型底栖动物采样调查。运用较大的空间尺度和以食性为基础的功能群研究方法,研究象山港大型底栖动物功能群组成及其多样性。根据食性类型将底栖动物划分为浮游生物食者（P1）、植食者（Ph）、肉食者（C）、杂食者（O）和碎屑食者（D）5个功能群。各功能群所含物种种类...  相似文献   

无人值守台站运维监控微信小程序设计与实现     

丁晓光  翟宏光  何杨  张艺  苏利娜 《震灾防御技术》2021,16(4):756-762

通过设计无人值守台站自动化监控程序和微信小程序,实现监控台站故障报警、手机微信界面交互信息显示、后台分析统计及自动生成标准化报告等功能,使台站日常维护、故障告警处置、例行巡检等一系列工作更简便易行且规范,提高台站运维效率。研究结果对数量日益增加的无人值守台站运维具有较高的推广应用价值,丰富多样的微信接口为日后功能扩展提供了充足空间。  相似文献   

盘锦芦苇湿地现状及可持续发展对策     

陈曦  李东 《湿地科学与管理》2014,(3):46-48

分析了盘锦芦苇湿地形成、芦苇湿地生态系统服务功能价值、芦苇产业现状,针对目前盘锦芦苇湿地存在的主要问题,提出了盘锦芦苇湿地可持续发展对策,促进实施科技兴苇战略,实现产业增效、职工增收,最终达到人与自然的和谐发展。  相似文献   

Effects of the construction of Scroby Sands offshore wind farm on the prey base of Little tern Sternula albifrons at its most important UK colony     

Perrow MR  Gilroy JJ  Skeate ER  Tomlinson ML 《Marine pollution bulletin》2011,62(8):1661-1670

Despite widespread interest in the impacts of wind farms upon birds, few researchers have examined the potential for indirect or trophic (predator-prey) effects. Using surface trawls, we monitored prey abundance before and after construction of a 30 turbine offshore wind farm sited close to an internationally important colony of Little terns. Observations confirmed that young-of-the-year clupeids dominated chick diet, which trawl samples suggested were mainly herring. Multivariate modelling indicated a significant reduction in herring abundance from 2004 onwards that could not be explained by environmental factors. Intensely noisy monopile installation during the winter spawning period was suggested to be responsible. Reduced prey abundance corresponded with a significant decline in Little tern foraging success. Unprecedented egg abandonment and lack of chick hatching tentatively suggested a colony-scale response in some years. We urge a precautionary approach to the timing and duration of pile-driving activity supported with long-term targeted monitoring of sensitive receptors.  相似文献   

EU marine strategy framework directive (MSFD) and marine spatial planning (MSP): Which is the more dominant and practicable contributor to maritime policy in the UK?     

《Marine Policy》2014

This paper is a comparative analysis of the contribution to UK marine governance of two recent EU initiatives: the Marine Strategy Framework Directive (MSFD) and Marine Spatial Planning (MSP). MSFD imposed a duty on Member States to achieve Good Environmental Status (GES) in four regional seas, while MSP required Member States to replace their fragmented, sector-based system of maritime decision making with an integrated approach. This paper explains MSFD and MSP, examines their relationship, and compares their practicability, concluding that MSP is both the more dominant and the more practicable instrument, reflecting the UK's preference for sustainable development over conservationism in marine policy. A recent proposal by the European Commission to make MSP and integrated coastal management a Directive reinforces the UK position.  相似文献   

Characterization of the light attenuation by periphyton in lakes of different trophic state   总被引：1，自引：0，他引：1  

Uta Raeder  Johannes Ruzicka  Cornelia Goos 《Limnologica》2010,40(1):40-46

In order to measure the attenuation of light by periphyton a method has been developed which assures that natural periphyton architecture and therefore its optical characteristics remain preserved. This method has been applied to analyze the transmittance of periphyton of four lakes of different tropic states situated in the Osterseen Lake District (Upper Bavaria, Germany). The seasonal variation of the periphyton's transmittance has been studied using standard microscope glass slides exposed 1 m beneath the water surface within macrophyte beds. The study ran from February to November 1997 in two eutrophic lakes (Lake Waschsee, Lake Sengsee) and from May to November 1997 in the meso-oligotrophic Lake Eishaussee and in the oligotrophic Lake Herrensee.Generally the exposure-period, the seasonality, and the tropic state of the habitat affected the transmittance spectra of the periphyton. In all lakes the attenuation by periphyton increased with longer colonization times but at a different time scale. The periphyton of the nutrient-rich and the nutrient-poor lakes differed clearly in composition and architecture. The eutrophic lakes were characterized by a relatively thick but loosely attached, unstable periphyton community, which was translucent to a certain degree even at the end of the growth period. The transmittance of this periphyton fluctuated considerably and high percentages of filamentous green algae in this periphyton contributed to attenuation maxima within the range 400-500 nm and 650-700 nm due to photosynthetic pigments. By contrast, the periphyton of the meso-oligotrophic and of the oligotrophic lake was quite compact and nearly impervious to light.  相似文献   

资源三号卫星在轨测试与应用分析   总被引：2，自引：0，他引：2  

唐新明  谢俊峰 《地理信息世界》2013,(2):37-40,51

资源三号卫星是我国首颗民用高分辨率三线阵立体测绘卫星,卫星在轨运行至今一年多,卫星影像产品在测绘及其他行业得到了广泛的应用。本文主要阐述资源三号卫星发射后的总体运行状态及卫星数据的应用情况,并在此基础上提出发展我国后续光学测绘卫星的建议与思考。  相似文献   

An environmental assessment of risk in achieving good environmental status to support regional prioritisation of management in Europe     

P. Breen  L.A. Robinson  S.I. Rogers  A.M. Knights  G. Piet  T. Churilova  P. Margonski  N. Papadopoulou  E. Akoglu  A. Eriksson  Z. Finenko  V. Fleming-Lehtinen  B. Galil  F. Goodsir  M. Goren  O. Kryvenko  J.M. Leppanen  V. Markantonatou  S. Moncheva  T. Oguz  L. Paltriguera  K. Stefanova  F. Timofte  F. Thomsen 《Marine Policy》2012

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Resource depletion affects the structure of an experimental benthic food web     

《Limnologica》2016

In this study, we investigated the long-term (2-year) response of a detritus-based food web to resource depletion simulated in microcosms filled with lake sediment. The effects of resource depletion on the food web were estimated from the biomass responses of a simplified, size-based trophic network comprising three trophic levels: (1) bacteria, (2) bacterivorous meiofauna, and (3) omnivore/predacious nematodes and oligochaetes. The results showed that sediment bacteria and organic carbon stock were not affected by resource depletion, whereas oligochaetes, large nematodes and some bacterivores, such as rotifers and ostracods, decreased dramatically. At the same time, resource depletion had no negative effect on minute bacterivorous nematodes and harpacticoid copepods, suggesting their release from competition with other bacterivores and/or their release from potential predation by large nematodes and oligochaetes. Our results globally confirmed classical trophic dynamics models in which a shortage in resources dampens food-chain length. Yet, low resources did not completely eliminate all large invertebrates, and did not affect the standing stock of detritus and bacteria, suggesting that detritus-based food webs could show a remarkable resilience to the effects of resource depletion.  相似文献