From Lake to The Sea: Meiofaunal Biodiversity Along The Adayar Wetland Complex With its Marine Continuum and Their Implications on Their Environ

Meiofauna are minute benthic invertebrates inhabiting the aquatic sediments. The study area includes the Adyar Wetland Complex which consists of the Chembarambakkam lake-Adyar River- Adyar Estuary and its marine continuum-the Edward’s Elliots beach. The current study investigates the variation in density, distribution, and diversity of meiofaunal groups across the distinct ecological niches of the study area: freshwater (lake and riverine), estuarine, and marine zones using the Simpson’s diversity index, Shannon wiener index and Species evenness index. Sediment samples were collected from these four sampling stations and were decanted, sieved and sorted for meiofauna. The sorted meiofauna were identified (upto the phylum level) using taxonomic keys and pictorial guides. A total of 950 meiofauna across the continuum were counted out of which, 551exs were nematodes, 80 exs harpacticoid copepods, 56 exs foraminiferans, 45 exs ostracods and 218 exs were of other taxa (which includes acari, amphipoda, polychaeta, archiannelida etc). In all the four sample stations nematodes and harpacticoid copepods were the dominant taxa. Upon comparing the diversity patterns it was found that the Chembarambakkam lake had the most diverse groups of meiofaunal communities followed by the Adyar estuary due to high species dominance in the estuarine region. When the population density among the taxa were compared it was evident that the estuarine region had more population density followed by marine. In both of the above criteria, the Adayar river zone was found to be trailing far behind. This variation could be influenced by factors like salinity, sediment texture, nutrient availability and anthropogenic interference.The findings of this study can be resourceful in postulating conservation strategies, by identifying sensitive zones across the Adayar wetland complex, which is indicated by a sudden plunge in diversity and density of certain meiofaunal taxa. Since meiofauna are pollution indicators their diversity provides valuable insights into the extent of damage done to their ecological niche. Results from the present study can be used in fields such as environmental management, aquatic ecology, and climate change studies, particularly in understanding how meiofauna respond to environmental gradients and reverse inferences.