Spatio-temporal dynamics of a planktonic system and chlorophyll distribution in a 2D spatial domain: matching model and data

Abstract

Field data on chlorophyll distribution are investigated in a two-dimensional spatial domain of the Mediterranean Sea by using for phytoplankton abundances an advection-diffusion-reaction model, which includes real values for physical and biological variables. The study exploits indeed hydrological and nutrients data acquired in situ, and includes intraspecific competition for limiting factors, i.e. light intensity and phosphate concentration. As a result, the model allows to analyze how both the velocity field of marine currents and the two components of turbulent diffusivity affect the spatial distributions of phytoplankton abundances in the Modified Atlantic Water, the upper layer of the water column of the Mediterranean Sea. Specifically, the spatio-temporal dynamics of four phytoplankton populations, responsible for about 80% of the total chlorophyll a, are reproduced. Results for phytoplankton abundances obtained by the model are converted in chlorophyll a concentrations and compared with field data collected in twelve marine sites along the Cape Passero (Sicily)- Misurata (Libya) transect. Statistical checks indicate a good agreement between theoretical and experimental distributions of chlorophyll concentration. The study can be extended to predict the spatio-temporal behaviour of the primary production, and to prevent the consequent decline of some fish species in the Mediterranean Sea.

First annulus formation in the European anchovy; a two-stage approach for robust validation

“…In both these areas the habitat conditions are characterized by higher riverine input nutrients and higher productivity 25,31 than the oligotrophic waters of the study area and of the most part of the Mediterranean Sea 26 . The Strait of Sicily is considered an oligotrophic area 34,35,64 , where the enrichment of the upper water layers is associated with upwelling phenomena, which allow nutrient inputs from deeper waters 27,65 . Literature widely reported the variability in somatic growth linked to habitat variability e.g.…”

“…In Mediterranean Sea, studies aiming at anchovy age validation are very scarce and pertain only to the NW area 31 . Indeed, the NW Mediterranean is among the most productive areas in the Mediterranean Sea 32,33 , thus not easily comparable with the oligotrophic nature of the study area (Strait of Sicily) 34,35 . Furthermore, none of the previous investigations used physiological information to support the results of the otolith analyses.…”

HR3DHG version 1: modeling the spatiotemporal dynamics of mercury in the Augusta Bay (southern Italy)

“…In the HR3DHG model, the mercury exchange between the abiotic and biotic compartments is also taken into account. For this purpose, the spatiotemporal behavior of picoeukaryote abundance is reproduced by the Nutrient-Phytoplankton (NP) model (Denaro et al, 2013a, c;Valenti et al, 2015Valenti et al, , 2016aValenti et al, , b, 2017) (see Sect. S4 of the Supplement for details).…”

“…Moreover, the role played by the spatiotemporal behavior of phytoplankton (La Barbera and Spagnolo, 2002;Fiasconaro et al, 2004;Valenti et al, 2004Valenti et al, , 2008Dutkiewicz et al, 2009;Morozov et al, 2010;Valenti et al, 2012;Denaro et al, 2013a, b, c;Valenti et al, 2015Valenti et al, , 2016aValenti et al, , b, c, 2017Morozov et al, 2019) and the mechanisms responsible for the uptake of Hg within cells (Pickhardt and Fischer, 2007;Radomyski and Ciffroy, 2015;Lee and Fischer, 2017;Williams et al, 2010) are taken into account as specific contributions to the scavenging process and Hg release process by POM, respectively. Also, seasonal oscillations of key environmental variables (velocity of marine currents, amount of precipitation, elemental and inorganic mercury concentration in the atmosphere, etc.)…”

Marine ecosystems and living resources in the Central Mediterranean Sea: an introduction

“…In particular, work is still needed to develop exhaustive models describing the processes driving the energy exchange along the trophic food web levels from the primary producers up to top consumers (Rumolo et al, 2016). Although its relevance, only few studies have already addressed this subject in the Central Mediterranean (e.g., Bonomo et al, 2012;Valenti et al, 2012Valenti et al, , 2017Denaro et al, 2013a, b). In the present volume, some attributes of the physical-chemical environment that are relevant to phytoplankton and zooplankton research have been studied for the Central Mediterranean.…”