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Health of an ecosystem is very much important as we depend on its goods and services for our existence. Because of this, we need to continuously monitor its health for human benefit and for identifying areas for improvement of our natural systems. The present study tries to assess the condition of a coastal ecosystem within the Vembanad Lake, Kerala, India, using key water quality parameters at micro-level. Principal component analysis identified the minimum required water quality dataset for further analysis and was scored using linear scoring functions. The weighted additive method was used to integrate the individual scores to arrive at a final score representing the ecosystem health. Spline interpolation was applied to develop the ecosystem health map of the study area. Using this method, 35.8% area of the aquatic ecosystem studied was characterized as good, 32.2% as moderate, 26.2% as fair and 5.8% as poor. The assessment results can help the policymakers/managers to make appropriate decisions for the better management of the coastal ecosystems studied. Moreover, this methodology can be replicated for the assessment of coastal regions with similar ecosystem characteristics.

A preliminary report on the abundance of microplastic in the coastal waters in the depth zone 5 to 20 m in the surface waters, sediment and in selected fishes occurring off Kochi, India is presented. Spatial and temporal variation in microplastic abundance was observed with higher abundance in surface water indicating threats to pelagic ecosystem. The relative concentration of microplastic was highest during monsoon season. The major microplastics were fragments of 1-5 mm in white and blue colours. Gut content analysis of 16 species (653 individuals) comprising pelagic (8 species) and demersal (8 species) indicated occurrence (4.6%) of microplastics (fragment>filament>pellet) of size 0.27mm to 3.2 mm in Sardinella longiceps, S. gibbosa, Stolephorus indicus Rastrelliger kanagurta and Cyanoglossus macrostomus. Raman spectroscopy indicated that Polyethylene (PE) and Polypropylene (PP) were the polymer types of microplastics from the fish gut.

Impact of microplastic pollution on the marine environment and its biota is a major concern globally. Gulf of Mannar (GoM) and Palk Bay (PB) are two important biodiversity hotspots along the south-east coast of India. However, in the recent years the intense tourism and fishery activities have made the ecosystem and biota of these two ecologically significant coastal zones vulnerable to microplastic contamination. Hence, a comparative study on the seasonal distribution of microplastics in the surface waters, sediments, and in commercially important fishes were conducted to evaluate the threats imposed by microplastics on the environment and biota of both these coastal ecosystems. Microplastic distribution in the surface waters and sediments of GoM and PB exhibited conspicuous seasonal variation and showed positive correlation with the seasonal current patterns. In the surface waters of GoM, microplastics were abundant during the South West Monsoon whereas in PB it was high during the Early Winter Monsoon period. In the sediments of PB, microplastics was more during Spring Inter-monsoonand South West Monsoon whereas in GoM it was high during Late Winter Monsoon. Fragments, of size 1 to 5 mm formed the abundant microplastic type in the surface waters whereas in the sediments, fragments of size

The seagrass meadows of Sethukarai coast are unique in nature, housing high faunal diversity compared to other coastal areas. A rare live specimen of bandtail scorpionfish Scorpaenopsis neglecta was found near a burrow dug by an alpheid shrimp. Taxonomy, morphometric and meristic characters, adaptive, behavioural and colour-switching physiological camouflage trait of the S. neglecta are elaborated in this communication. Visual in situ documentation of feeding habits of scorpaenids and their preying behaviour, especially that of lionfish Pterois volitans preying on goby fish is presented. Mutualism exhibited by goby fish Amblyeleotris gymnocephala with the alpheid shrimp Alpheus rapax and the importance of habitat protection from anthropogenic activities are also discussed.

The Indian marine environment, consisting of adjoining coastal areas and the exclusive economic zone (EEZ), directly sustains useful habitats and supports the livelihood of 3.9 million fishers. The average marine fisheries production of the country during the period 2010–2015 has been estimated at 3.36 million tons consisting of approximately 667 different fish species inhabiting the neritic zone that depend on the productivity of marine ecosystem and in turn are influenced by the reactive nitrogen (Nr) available in the system. During the past three decades significant advances have been made in industry, agriculture, fisheries, and other sectors and these have resulted in the release of Nr influencing the N-cycle in the coastal and marine ecosystems. Nitrogen assessment of the surface waters carried out in the EEZ and adjoining areas during the years 1998–2007 revealed that the annual concentrations (μM) of NO 2 ranged from 0 to 0.4, 0 to 0.6, and 0 to 0.7 in the Arabian Sea, Bay of Bengal, and Andaman Sea, respectively. The corresponding values for NO 3 (μM) were 0–2.5, 0–3, and 0–3.5, respectively. Nr transfer to the marine environment also influences eutrophication, algal blooms, changes in the ecological processes and habitats affecting ecosystem health. In this chapter, the present status of Nr assessment in the coastal and marine ecosystems in the country has been reviewed, its interaction with marine aquaculture listed, and the need for future research thrusts, especially on prediction of the extent and direction of impacts of altered nitrogen fluxes on the coastal and marine resources including diversity of faunal and floral community structure is discussed.

Arabian Sea considered as one of the richest region of oceanic cephalopods. On conflicting information related to species diversity is still scare. This work presents the first report of a paralarvae of glass octopus Vitreledonella richardi from the Arabian Sea. A single specimen was collected during dusk by Isaacs-Kidd midwater trawl net on 28 February 2015. (Horizon of 150 m at 09° 52′ 30″ N; 73° 37′ 22″ E, bottom depth: 2005 m). A description of the specimen is provided. Record of this rare squid, from Arabian Sea is an addition to the cephalopod fauna of India.