Wet and dry seasons modulate coastal coccolithophore dynamics off South-western Nigeria (Gulf of Guinea)
Adekunbi, Falilu O. (Universitat Autònoma de Barcelona. Institut de Ciència i Tecnologia Ambientals)
Grelaud, Michael (Universitat Autònoma de Barcelona. Institut de Ciència i Tecnologia Ambientals)
Langer, Gerald (Universitat Autònoma de Barcelona. Institut de Ciència i Tecnologia Ambientals)
Chukwu, Lucian O. (University of Lagos)
Alvarez, Marta (Instituto Español de Oceanografía (A Coruña))
Odunuga, Shakirudeen (University of Lagos)
Schulz, Kai G. (Southern Cross University (Australia))
Ziveri, Patrizia (Universitat Autònoma de Barcelona. Departament de Biologia Animal, de Biologia Vegetal i d'Ecologia)

Date:	2025
Description:	16 pàg.
Abstract:	Coccolithophores are calcifying unicellular phytoplankton at the base oxf the marine food web, playing a key role in pelagic calcium carbonate production. While their sensitivity to environmental change is well established, their ecological importance in tropical coastal systems remains underexplored, particularly along the African coastline. Here, we present the first multi-seasonal assessment of living coccolithophore communities off Lagos, southwest Nigeria, in the Gulf of Guinea. Periodic sampling was conducted at three coastal stations from December 2018 to April 2021 to evaluate species composition, standing stocks, diversity, and ecological drivers. Coccolithophore abundances showed clear seasonal patterns, with significantly higher (p<0. 05) standing stocks and diversity during the wet season. Total abundances ranged from 0. 3×103 cells L-1 in the dry season to 5. 5×103 cells L-1 in the wet season, with Gephyrocapsa oceanica dominating dry periods and Emiliania huxleyi prevailing during the wet season. Seasonal changes were linked to the migration of the Intertropical Convergence Zone (ITCZ), which modulates precipitation and current direction along the Gulf of Guinea. Interestingly, chlorophyll a concentrations appeared decoupled from coccolithophore abundance, suggesting other phytoplankton groups may drive primary productivity in this region. Despite regional differences in oceanographic settings, the observed standing stocks fall within the global range of coastal coccolithophore assemblages, supporting the hypothesis that these communities are shaped by a set of common ecological constraints. As tropical coastal regions already face multiple pressures from climate change, projected southward shifts of the ITCZ could alter precipitation regimes and current dynamics, with potential implications for coccolithophore community composition and coastal biogeochemical cycling.
Grants:	Agencia Estatal de Investigación PID2020-113526RB-I00 Ministerio de Ciencia, Innovación y Universidades PCI2025-163190 Generalitat de Catalunya 2021/SGR-00640 Ministerio de Ciencia, Innovación y Universidades CEX2024-001506-M Agencia Estatal de Investigación PTA2016-12441-I Ministerio de Ciencia e Innovación PEJ2018-003991-A
Note:	Unidad de excelencia María de Maeztu CEX2019-000940-M
Rights:	Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, la comunicació pública de l'obra i la creació d'obres derivades, fins i tot amb finalitats comercials, sempre i quan es reconegui l'autoria de l'obra original.
Language:	Anglès
Document:	Article ; recerca ; Versió publicada
Subject:	SDG 13 - Climate Action ; SDG 14 - Life Below Water
Published in:	Biogeosciences, Vol. 22, Num. 23 (December 2025) , p. 7865-7880, ISSN 1726-4189

DOI: 10.5194/bg-22-7865-2025

16 p, 6.1 MB

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Research literature > UAB research groups literature > Research Centres and Groups (research output) > Experimental sciences > Institut de Ciència i Tecnologia Ambientals (ICTA)
Articles > Research articles
Articles > Published articles