AquaEcology GmbH & Co. KG, Steinkamp 19, 26125, Oldenburg, Germany.
Institute for Terrestrial and Aquatic Wildlife Research (ITAW), University of Veterinary Medicine Hannover, Foundation, Werftstr. 6, 25761, Büsum, Germany.
Environ Monit Assess. 2021 Sep 19;193(10):662. doi: 10.1007/s10661-021-09435-x.
Replicate surveys of beach litter have seldom been performed in the past. In this study, replicate surveys of beach litter were conducted on the beach north of Hörnum (Sylt, Germany), from 2015 to 2019, applying a slightly modified OSPAR protocol of beach litter monitoring. Descriptive statistics and power analyses were calculated on data resulting from these replicate surveys, to find out whether the scatter of replicate beach litter data decreases and the statistical power increases with increasing numbers of replicate surveys. From 2015 to 2019, mean total abundances, given as numbers of litter items, ranged from 19 to 185 litter items on a 50 m section of beach. With increasing numbers of replicate surveys, the scatter given by the coefficient of variation (CV) significantly increased up to 113%. Statistical power considerably increased with increasing numbers of replicate beach sections, e.g. from 82% (two beach sections) to nearly 100% (five beach sections) for a given reduction of beach litter of 50%. Based on these results from a morphologically straight coastline, the use of replicate surveys would be sensible for the future monitoring of beach litter. However, there is high need for studies, which consider coastlines with varying morphology.
过去，海滩垃圾的重复调查很少进行。在这项研究中，2015 年至 2019 年，在德国叙尔特岛赫恩努姆（Hörnum）以北的海滩上，对海滩垃圾进行了重复调查，采用了稍微修改过的 OSPAR 海滩垃圾监测协议。对这些重复调查产生的数据进行了描述性统计和功效分析，以确定随着重复调查次数的增加，重复海滩垃圾数据的分散程度是否减小，统计功效是否增加。2015 年至 2019 年，在 50 米长的海滩段上，平均总丰度（以垃圾数量表示）范围为 19 至 185 个垃圾。随着重复调查次数的增加，变异系数（CV）给出的分散程度显著增加，最高可达 113%。随着重复海滩段数量的增加，统计功效显著提高，例如，对于给定的海滩垃圾减少 50%，从两个海滩段的 82%（两个海滩段）增加到五个海滩段的近 100%。基于这条形态上笔直的海岸线的结果，如果未来要对海滩垃圾进行监测，重复调查是合理的。然而，有很高的需求来研究不同形态海岸线的情况。
