A statistical assessment of plastic associated marine organisms found on intertidal plastic debris off the coasts of South Andaman Island of the Indian Archipelago

The purpose of this study is to relate the distribution and diversity of organisms found in association with plastic debris from South Andaman intertidal ecosystem using several statistical functions. In this study, ten different sites at South Andaman Island were examined for six months for plastic debris of various shape, size and colour along with the concerned organism. A total of 34 species of fauna and 17 species of flora are found associated with the plastic debris from this study. The most common ones are Arthropods, Bryozoans, Annelids and Rhodophyta. Few rare ones are sea anemones-Anthopleura handi and Actinia equina which were also seen attached on hard plastic objects. Diversity analysis highlighted the species evenness and diversity of Mazar Pahad to be maximum and species richness of Brookshabad to be the highest. No correlation was seen between the colour of plastic and the associated organism. Barnacle, Spirorbis and Sea Anemone prefer hard-rigid plastic fragments, whereas Bryozoans prefer a flexible, smooth surface. Lepas, on the other hand, preferred bottle caps, rubber material, and ropes. Many polychaetes were found in almost all the stations indicating that the coast and the water are quite polluted. Correlation between debris size and the number of taxa group showed stochastic phenomenon. Positive correlation was seen among the colony size of taxa group in relation with the exposed area of the debris. In terms of the distribution of plastic debris across the various zones of the intertidal region and the preference of the specific flora or fauna groups, no general trends or pattern was observed. Through this study, it is understood that plastic in one way provides shelter to certain organisms but at the same time harms other organisms through invasion as well as by providing an unnatural habitat. (C) 2021 Elsevier B.V. All rights reserved.