Assessment of the uncertainty of trace metal and nitrogen concentrations in mosses due to sampling,sample preparation and chemical analysis based on the French contribution to ICP-Vegetation

Moss bio-monitoring is a convenient tool for establishing specific or large-scale exposure to atmospheric trace metals and nitrogen pollution. However, the uncertainty associated with sampling, sample preparation and chemical analysis of bio-monitors has been poorly documented, with the exception of one study dealing with lichens; thus, the uncertainty associated with moss bio-monitoring has never been assessed. Here, we propose following the Eurachem guidelines to determine the uncertainties associated with the concentrations of elements measured in mosses during the sampling survey across France in 2011. In addition, we assess the analytical method used in four surveys from 1996 to 2011. Uncertainties were expressed as linear functions of the element concentrations, with minimum and maximum slopes of 14 and 61%, corresponding to nitrogen and chromium, and a median of 32%. Although the data reveal that some steps of the protocol should be performed carefully, they also indicate that the protocol was executed properly and is reproducible. The chemical analyses contribute to a small proportion of the uncertainty associated with the protocol, except for the analysis of chromium. The sampling period, and intra-site variability largely contribute to this uncertainty. The moss species did not introduce additional uncertainty. This integrative assessment of measurement uncertainty will help improve the protocol for future surveys. Such studies could be useful for developing a standard operating procedure and could be used to improve comparisons between countries and to identify temporal trends across Europe.     

用微型生物群落评价常德市水系的研究

本文应用PFU法对常德水系四季微型生物群落的结构和功能进行了分析。根据MacArthur-Wilson平衡模型提出了3个功能参数,测定了微型生物的2个结构参数。同步进行了16个站四季的水质分析,提出化学综合污染指数(P)。经统计学处理,P和微型生物群落的HI、S_(eq)、G、T_(90％)等指数均呈显著性相关。物种多样性(d)也在一定程度上反映出城市水体的不同污染程度。再次证明PFU微型生物监测方法的科学性,为生物监测提供了快速、经济、正确的新方法。     

三种重金属元素在鹭卵中富集特征的初步研究

2004年4～6月,采集了合肥地区大蜀山、肥西圆通山、肥东太子山集群繁殖的夜鹭、小白鹭、池鹭和牛背鹭鸟卵及组织样品,用原子吸收法测定了卵壳、内容物及组织中Cd、Pb、Cr的残留量.结果表明,4种鹭卵壳、内容物及组织的绝大多数样品中均检出相当高水平的Cd、Pb和Cr残留量,且卵壳和骨骼是重金属富集的主要场所,表明通过卵壳可以排出体内部分重金属污染物.卵壳中重金属显著高于卵内容物,卵壳中重金属残留量为Cr＞Pb＞Cd,4种鹭卵壳中重金属残留量的种间差异都极其显著,Cr残留水平的种间波动幅度最大,池鹭卵壳中的最高,牛背鹭的最低;Pb的种间波动幅度相对较小,Cd的种间波动幅度最小;而卵内容物中3种重金属残留量的种间差异都不显著,Cr残留量种间波动幅度最大,池鹭卵内容物中,Cr含量最高,牛背鹭卵内容物中没有检出;Pb的种间波动幅度相对较小,Cd的种间波动幅度最小.由于鹭的卵壳取样容易,可用作重金属污染物的指示物,监测和评价湿地生态系统中重金属的污染状况.     

Investigating the viability of photo-identification as an objective tool to study endangered sea turtle populations

We assessed the potential of using natural facial markings to identify individuals in an endangered breeding population of loggerhead sea turtles (Caretta caretta). We divided individual turtles into ten groups based on facial (post-ocular) scale patterns to facilitate rapid comparison of new images in a large photographic catalogue of known turtles (exceeding 400 unique individuals). The matching process was validated by using turtles marked with external flipper tags. An experienced observer achieved a mean 99% success in identifying individuals using photo-id. The reliability and wider utility of the technique was assessed through testing the ability of naïve and trained observers to (1) consistently allocate known (i.e. flipper tagged) individuals into the correct groups (2) correctly match known individuals within one group. In all trials the mean success rate in photographic sorting and matching ranged from 68-100%. A 20 minute training session was found to significantly improve observer ability, i.e the photo-id skills were rapidly acquired by inexperienced workers. Photo-id has the benefit of being suitable for male turtles, which do not come ashore to allow conventional tagging, and so are rarely identified. Photo-id may facilitate the assessment of the numbers of male and female turtles at breeding areas and allow adult sex ratios to be measured.