title: Human-induced ecological changes in western part of Indian Sundarban megadelta: A threat to ecosystem stability.
abstract: The study first illustrates a comprehensive account of large-scale changes in water quality characteristics and plankton community structure due to occurrence of Annual Gangasagar Festival (AGF) at Sagar Island, western part of Indian Sundarban megadelta for 3-year duration (2012-2014; n=36). About 1 million pilgrims across India converge to take their holy bath at the confluence of Hooghly estuary and Bay of Bengal during January each year. This mass scale bathing results negative impact on water quality due to high turbidity (14.02 ± 2.34 NTU) coupled with low chlorophyll a (1.02 ± 0.21 mg m(-3)) and dissolved oxygen (3.94 ± 1.1 mg l(-1)). A marked decrease in abundance (from 4140 to 2997 cells l(-1)) and diversity (H'=2.72-1.33) of phytoplankton and microzooplankton tintinnids (from 450 to 328 ind l(-1); H'=4.31-2.21) was recorded. The festival acts as multiple stressors modifying natural functions of the delta. Sound and sustainable management strategies are to be adopted to maintain the protection-usage equilibrium.
authors.affiliation: Department of Marine Science, University of Calcutta, 35, Ballygunge Circular Road, Calcutta 700019, India.
authors.forename: Dibyendu
authors.initials: D
authors.lastname: Rakshit
authors.affiliation: Department of Marine Science, University of Calcutta, 35, Ballygunge Circular Road, Calcutta 700019, India. Electronic address: cusarkar@gmail.com.
authors.forename: Santosh Kumar
authors.initials: SK
authors.lastname: Sarkar
authors.affiliation: Department of Marine Science, University of Calcutta, 35, Ballygunge Circular Road, Calcutta 700019, India.
authors.forename: Bhaskar Deb
authors.initials: BD
authors.lastname: Bhattacharya
authors.affiliation: Centro Interdisciplinario de Investigaciones y Estudios sobre Medio Ambiente y Desarrollo (CIIEMAD), Instituto Politécnico Nacional (IPN), Calle 30 de Junio de 1520, Barrio la Laguna Ticomán, Del. Gustavo A. Madero, 07340 Mexico, DF, Mexico.
authors.forename: M P
authors.initials: MP
authors.lastname: Jonathan
authors.affiliation: Department of Ecological Engineering & Environmental Management, International Centre for Ecological Engineering, University of Kalyani, Nadia, 741235, India.
authors.forename: Jayanta Kumar
authors.initials: JK
authors.lastname: Biswas
authors.affiliation: Department of Marine Science, University of Calcutta, 35, Ballygunge Circular Road, Calcutta 700019, India.
authors.forename: Priyanka
authors.initials: P
authors.lastname: Mondal
authors.affiliation: Department of Marine Science, University of Calcutta, 35, Ballygunge Circular Road, Calcutta 700019, India.
authors.forename: Soumita
authors.initials: S
authors.lastname: Mitra
mesh_terms: D000818:Animals; D002734:Chlorophyll / Q000032:analysis; D000077194:Chlorophyll A; D017753:Ecosystem; D004777:Environment; D063366:Estuaries; D006801:Humans; D007194:India; D010839:Phytoplankton / Q000502:physiology*; D010933:Plankton / Q000502:physiology; D011998:Recreation; D060753:Water Quality; D015048:Zooplankton / Q000502:physiology
chemical_list: D002734:Chlorophyll; D000077194:Chlorophyll A
keywords: Gangasagar festival; Hooghly estuary; Phytoplankton; Sundarban megadelta; Tintinnid; Water quality