The use of multivariate statistical techniques to establish beach debris pollution sources

Abstract

Beach litter found along the Bristol Channel and the coastline of mid-Wales, UK, together with litter obtained from Turkey, Malta, Spain, Tunisia and U.S.A. tourist beaches, and litter gathered from rural roads in Gloucestershire, England, UK, was analyzed by principal component analysis (PCA). PCA distinguished between riverine, sewage-related debris and shipping/fishing source items, but sourcing beach user litter was more problematic. This was attributed to a difference in litter transport mechanisms. PCA for the Bristol Channel distinguished between riverine and marine sources (inner vs. outer channel) and also a sewage sourced group. PCA indicated a land-based source for marine debris found on Mediterranean and USA beaches together with roadside litter from England. Three 'litter markers' introduced into the analyses, were comprised of different source groupings: 'vessels' (both fishing and other sea going vessels), 'beach users', and sewage-related debris (SRD). The former stood out from the latter two markers with beach user and SRD markers appearing to be indistinguishable. The item numbers in each group were six, five and three respectively and this could account for the findings.