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Indian coastal waters are critical for dugong populations in the western Indian Ocean. Systematic spatial planning of dugong habitats can help to achieve biodiversity conservation and area-based protection targets in the region. In this study, we employed environmental niche modelling to predict suitable dugong habitats and identify influencing factors along its entire distribution range in Indian waters. We examined data on fishing pressures collected through systematic interview surveys, citizen-science data, and field surveys to demarcate dugong habitats with varying risks. Seagrass presence was the primary factor in determining dugong habitat suitability across the study sites. Other variables such as depth, bathymetric slope, and Euclidean distance from the shore were significant factors, particularly in predicting seasonal suitability. Predicted suitable habitats showed a remarkable shift from pre-monsoon in Palk Bay to post-monsoon in the Gulf of Mannar, indicating the potential of seasonal dugong movement. The entire coastline along the Palk Bay-Gulf of Mannar region was observed to be at high to moderate risk, including the Gulf of Mannar Marine National Park, a high-risk area. The Andaman Islands exhibited high suitability during pre- and post-monsoon season, whereas the Nicobar Islands were highly suitable for monsoon season. Risk assessment of modelled suitable areas revealed that < 15% of high-risk areas across Andaman and Nicobar Islands and Palk Bay and Gulf of Mannar, Tamil Nadu, fall within the existing protected areas. A few offshore reef islands are identified under high-risk zones in the Gulf of Kutch, Gujarat. We highlight the utility of citizen science and secondary data in performing large-scale spatial ecological analysis. Overall, identifying synoptic scale 'Critical Dugong Habitats' has positive implications for the country's progress towards achieving the global 30 × 30 target through systematic conservation planning., (© 2024. The Author(s).)

Modern benthic foraminiferal assemblages are instrumental in providing information regarding changes in relative sea level as well as prevailing environmental conditions in marine environments. Marginal marine environments are coastal environments that are in most cases characterized by high influx of terrestrially originated nutrients. Inventorizing of modern benthic foraminiferal assemblages from such habitats can act as biotic indicators of water quality variations along with any changes in relative sea level. The present study documents the modern benthic foraminiferal assemblage from three major marginal marine habitats located along the North West coast of Bay of Bengal, in the Indian Ocean. Sediment samples for the purpose were thus collected from the Indian Sundarbans Delta, Chilika lagoon and the Gautami Godavari estuarine zone which encompasses the Kakinada bay. A total of 32 species of benthic foraminifera were documented during the study. The present observations were compared with previous reports of benthic foraminiferal diversity from these habitats and exhibited variability.

Two actinomycete strains, designated YIM M11168(T) and YIM M11177, were isolated from marine sediment samples from Little Andaman, Indian Ocean, and their taxonomic position was determined by a polyphasic approach. The two Gram-positive, aerobic strains were observed to produce branched substrate mycelium and aerial hyphae but did not fragment, and no diffusible pigment was produced on the media tested. At maturity, spores were formed singly or in pairs on aerial hyphae and substrate mycelium, and occasionally the single ones were borne on long sporophores. The optimum growth was determined to occur at 28 °C, 0-4 % (w/v) NaCl and pH 7.0-8.0. Whole-cell hydrolysates of both strains contained meso-diaminopimelic acid and the diagnostic sugars were determined to be galactose, glucose and arabinose. Their predominant menaquinone was found to be MK-9(H4). The polar lipids detected in the two strains were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol mannoside, phosphatidylinositol, phosphatidylmethylethanolamine, phosphatidylethanolamine and two unknown phosphoglycolipids. The major fatty acids (>10 %) identified were iso-C16:0, iso-C16:1 H, iso-C16:0, C17:1 ω6c for strain YIM M11168(T), iso-C16:0 and Summed Feature 3 for strain YIM M11177. The G + C contents of the genomic DNAs of both strains were determined to be 71.4 %. DNA-DNA hybridization relatedness values (78.4 ± 3.7 %) of these two isolates supported the conclusion that they belong to the same species. Based on phylogenetic analysis, phenotypic and genotypic data, it is concluded that the two isolates belong to a novel species of the genus Saccharomonospora of the family Pseudonocardiaceae. The name Saccharomonospora oceani sp. nov. (Type strain YIM M11168(T) = DSM 45700(T) = JCM 18128(T)) is proposed for the novel species.