A dead zone on the north-western Bay of Bengal's continental margin and its alarming impact on the distribution of demersal fishes

IF 2.1 3区地球科学 Q2 OCEANOGRAPHY

Continental Shelf Research Pub Date : 2025-02-01 DOI:10.1016/j.csr.2024.105398

Manjebrayakath Hashim, B.R. Smitha, K.V. Aneesh Kumar

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引用次数: 0

Abstract

Hypoxia in the mesopelagic and demersal realms of marine ecosystems directly or indirectly affects fish population structure, community composition and ecosystem functioning. This may result in excess mortality or the emigration of organisms from the area, resulting in dead zones. The present study reports on a dead zone on the north-western Bay of Bengal's continental margin with no discernible fish catch. The phenomenon is associated with stratification, small residence time of suspended matter in the water column and weak vertical/horizontal mixing due to a retention area (and increased biological flux) observed in the region as a result of cooccurring warm and cold core eddies, resulting intense decompose activities in the regional bottom. As with similar ocean zones globally, dominance of a single species (Parascombrops pellucidus) around the zone's periphery (edge effect) is also reported which is attributed to their feeding patterns, locomotory characteristics, prey preferences and availability. The dead zone's seasonal occurrence indicates the influence of natural or anthropogenically induced climatic variability can even affect demersal/bottom-dwelling organisms. The present work discusses the drivers and implications of dead zones using in situ oceanographic and fishery data, remote sensing observations and model outputs.

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来源期刊

Continental Shelf Research 地学-海洋学

CiteScore

4.30

自引率

4.30%

发文量

136

审稿时长

6.1 months

期刊介绍： Continental Shelf Research publishes articles dealing with the biological, chemical, geological and physical oceanography of the shallow marine environment, from coastal and estuarine waters out to the shelf break. The continental shelf is a critical environment within the land-ocean continuum, and many processes, functions and problems in the continental shelf are driven by terrestrial inputs transported through the rivers and estuaries to the coastal and continental shelf areas. Manuscripts that deal with these topics must make a clear link to the continental shelf. Examples of research areas include: Physical sedimentology and geomorphology Geochemistry of the coastal ocean (inorganic and organic) Marine environment and anthropogenic effects Interaction of physical dynamics with natural and manmade shoreline features Benthic, phytoplankton and zooplankton ecology Coastal water and sediment quality, and ecosystem health Benthic-pelagic coupling (physical and biogeochemical) Interactions between physical dynamics (waves, currents, mixing, etc.) and biogeochemical cycles Estuarine, coastal and shelf sea modelling and process studies.