Ecosystem-scale insights into the dynamics of dissolved organic matter in an Asia's largest brackish water lagoon: Sources, fluxes, and biogeochemical significance.

A twenty-four month long observational study conducted in an Asia's largest brackish water ecosystem, Chilika Lagoon, India, aimed to unravel dissolved organic matter (DOM) dynamics in this tropical brackish water ecosystem. The study assessed the interplay between allochthonous and autochthonous DOM sources during lean and active flow periods based on regional rainfall. Dissolved organic carbon (DOC), nitrogen (DON), and phosphorus (DOP) fluxes were analyzed, considering catchment runoff, phytoplankton production, benthic-pelagic interactions, and sea-lagoon exchanges as contributors.

Assessment of heavy metal distribution in seawater of Kakinada Bay, a tropical mangrove-rich coastal environment.

The main objective of the present study is to estimate the heavy metal concentrations and ecological risk index (ERI) in the seawater of Kakinada Bay. Turbidity, suspended particulate matter (SPM), pH, salinity, dissolved oxygen, along with heavy metals were recorded from twelve locations of the Bay to understand its hydrographical conditions. The distribution of environmental variables and heavy metal concentrations was noticed mostly from the south to north gradient.

Macrobenthic community of a tropical bay system revisited: Historical changes in response to anthropogenic forcing.

The present study examines historical perspectives of the macrobenthic community in response to different phases of anthropogenic perturbations in Kakinada Bay, a tropical embayment on the east coast of India. Multivariate analysis of the snapshot data (1958-2017) revealed considerable changes in the Bay environment following a breakwater construction across the Bay mouth in 1997. Subsequently, port expansion activities, industrialization, urbanization, and geomorphic alterations in the Godavari delta brought deterrent changes in the Bay.