title: How diffusivity, thermocline and incident light intensity modulate the dynamics of deep chlorophyll maximum in Tyrrhenian Sea.
abstract: During the last few years theoretical works have shed new light and proposed new hypotheses on the mechanisms which regulate the spatio-temporal behaviour of phytoplankton communities in marine pelagic ecosystems. Despite this, relevant physical and biological issues, such as effects of the time-dependent mixing in the upper layer, competition between groups, and dynamics of non-stationary deep chlorophyll maxima, are still open questions. In this work, we analyze the spatio-temporal behaviour of five phytoplankton populations in a real marine ecosystem by using a one-dimensional reaction-diffusion-taxis model. The study is performed, taking into account the seasonal variations of environmental variables, such as light intensity, thickness of upper mixed layer and profiles of vertical turbulent diffusivity, obtained starting from experimental findings. Theoretical distributions of phytoplankton cell concentration was converted in chlorophyll concentration, and compared with the experimental profiles measured in a site of the Tyrrhenian Sea at four different times (seasons) of the year, during four different oceanographic cruises. As a result we find a good agreement between theoretical and experimental distributions of chlorophyll concentration. In particular, theoretical results reveal that the seasonal changes of environmental variables play a key role in the phytoplankton distribution and determine the properties of the deep chlorophyll maximum. This study could be extended to other marine ecosystems to predict future changes in the phytoplankton biomass due to global warming, in view of devising strategies to prevent the decline of the primary production and the consequent decrease of fish species.
authors: Dipartimento di Fisica e Chimica, Università di Palermo, Group of Interdisciplinary Theoretical Physics and Consorzio Nazionale Interuniversitario per le Scienze Fisiche della Materia, Unità di Palermo, Palermo, Italy.
authors: Davide
authors: D
authors: Valenti
authors: Dipartimento di Fisica e Chimica, Università di Palermo, Group of Interdisciplinary Theoretical Physics and Consorzio Nazionale Interuniversitario per le Scienze Fisiche della Materia, Unità di Palermo, Palermo, Italy.
authors: Giovanni
authors: G
authors: Denaro
authors: Dipartimento di Fisica e Chimica, Università di Palermo, Group of Interdisciplinary Theoretical Physics and Consorzio Nazionale Interuniversitario per le Scienze Fisiche della Materia, Unità di Palermo, Palermo, Italy; Istituto Nazionale di Fisica Nucleare, Sezione di Catania, Catania, Italy; Radiophysics Department, Lobachevsky State University, Nizhniy Novgorod, Russia.
authors: Bernardo
authors: B
authors: Spagnolo
authors: Stazione Zoologica Anton Dohrn, Naples, Italy.
authors: Fabio
authors: F
authors: Conversano
authors: Stazione Zoologica Anton Dohrn, Naples, Italy.
authors: Christophe
authors: C
authors: Brunet
mesh_terms: D000465:Algorithms; D002734:Chlorophyll / Q000737:chemistry*; D008027:Light; D008522:Mediterranean Sea; D008962:Models, Theoretical; D009791:Oceanography; D010839:Phytoplankton / Q000502:physiology*; D012623:Seawater / Q000032:analysis / Q000737:chemistry*; D013696:Temperature
chemical_list: D002734:Chlorophyll
references: Am Nat. 2009 Aug;174(2):190-203
references: 19538096
references: Phys Rev E Stat Nonlin Soft Matter Phys. 2011 Aug;84(2 Pt 1):021134
references: 21928976
references: PLoS One. 2013;8(2):e56103
references: 23405255
references: FEMS Microbiol Ecol. 2007 May;60(2):189-206
references: 17391326
references: PLoS One. 2013;8(6):e66765
references: 23826130
references: J Theor Biol. 2009 Aug 7;259(3):582-8
references: 19409906
references: Phys Rev E Stat Nonlin Soft Matter Phys. 2007 Jan;75(1 Pt 2):016106
references: 17358223
references: Phys Rev E Stat Nonlin Soft Matter Phys. 2010 Jul;82(1 Pt 1):011121
references: 20866579
references: Nature. 2006 Jan 19;439(7074):322-5
references: 16421570
references: Microbiol Mol Biol Rev. 1999 Mar;63(1):106-27
references: 10066832
references: PLoS One. 2013;8(2):e56207
references: 23409156
references: Acta Biotheor. 2008 Jun;56(1-2):87-102
references: 18247135
references: PLoS One. 2013;8(2):e55093
references: 23405116
references: Int J Syst Evol Microbiol. 2000 Sep;50 Pt 5:1833-47
references: 11034495
references: Math Biosci Eng. 2004 Jun;1(1):185-211
references: 20369967
references: PLoS Biol. 2011 Oct;9(10):e1001177
references: 22028628
references: J Theor Biol. 2010 Aug 7;265(3):443-54
references: 20433853
references: Nature. 2005 Mar 31;434(7033):628-33
references: 15800620
references: Nature. 2001 Mar 15;410(6826):360-3
references: 11268210
references: Science. 2001 Jul 27;293(5530):638-43
references: 11474099
references: J Theor Biol. 2010 Mar 7;263(1):120-33
references: 19896955
references: Ecol Lett. 2011 Mar;14(3):220-8
references: 21265973
references: J Theor Biol. 2007 May 21;246(2):278-89
references: 17291537
references: Phys Rev E Stat Nonlin Soft Matter Phys. 2005 Oct;72(4 Pt 1):041104
references: 16383359
references: Nature. 2006 Dec 7;444(7120):752-5
references: 17151666