Primary Production in the Ligurian Sea

Mayot, Nicolas; Nival, Paul; Lévy, Marina

doi:10.1002/9781119706960.ch6

Cited by 5 publications

(2 citation statements)

References 86 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Annual upwelling and intense convective mixing maintain a seasonal supply of essential nutrients to the surface for phytoplankton growth at both locations (Sweeney et al (2003) for BATS; Marty et al (2008) for DYFAMED). Because of atmospheric dust input, iron availability does not limit phytoplankton growth either at BATS (Nelson & Brzezinski, 1997) or at DYFAMED (Mayot et al, 2020). Therefore, the increasing growth rate increases photosynthesis.…”

Section: Qoimentioning

confidence: 99%

Global sensitivity analysis of a one-dimensional ocean biogeochemical model

Mamnun,

Völker,

Krumscheid

et al. 2023

SESMO

View full text Add to dashboard Cite

Ocean biogeochemical (BGC) models are a powerful tool for investigating ocean biogeochemistry and the global carbon cycle. The potential benefits emanating from BGC simulations and predictions are broad, with significant societal impacts from fisheries management to carbon dioxide removal and policy-making. These models contain numerous parameters, each coupled with large uncertainties, leading to significant uncertainty in the model outputs. This study performs a global sensitivity analysis (GSA) of an ocean BGC model to identify the uncertain parameters that impact the variability of model outputs most. The BGC model Regulated Ecosystem Model 2 is used in a one-dimensional configuration at two ocean sites in the North Atlantic (BATS) and the Mediterranean Sea (DYFAMED). Variance-based Sobol' indices are computed to identify the most influential parameters for each site for the quantities of interest (QoIs) commonly considered for the calibration and validation of BGC models. The most sensitive parameters are the chlorophyll to nitrogen ratio, chlorophyll degradation rate, zooplankton grazing and excretion parameters, photosynthesis parameters, and nitrogen and carbon remineralization rate. Overall, the sensitivities of most QoIs were similar across the two sites; however, some differences emerged because of different mixed layer depths. The results suggest that implementing multiple zooplankton function types in BGC models can improve BGC predictions. Further, explicitly implementing heterotrophic bacteria in the model can better simulate the carbon export production and CO2 fluxes. The study offers a comprehensive list of the most important BGC parameters that need to be quantified for future modeling applications and insights for BGC model developments.

show abstract

Section: Qoimentioning

confidence: 99%

Global sensitivity analysis of a one-dimensional ocean biogeochemical model

Mamnun,

Völker,

Krumscheid

et al. 2023

SESMO

View full text Add to dashboard Cite

show abstract

“…Although much interest has been given to primary production and its trophic transfer in the Mediterranean Sea (Moran and Estrada 2001;Casotti et al 2003;Psarra et al 2005;Decembrini et al 2009;Kovač et al 2018;Mayot et al 2020), data acquired in its Southern basin are scarce (Sakka Hlaili et al 2008;Grami et al 2008;Meddeb et al 2018). Furthermore, little effort has been dedicated to describe how nutrient inputs and physical features affect the phytoplankton community structure and food web dynamics.…”

Section: Introductionmentioning

confidence: 99%

Influence of Nutrient Gradient on Phytoplankton Size Structure, Primary Production and Carbon Transfer Pathway in a Highly Productive Area (SE Mediterranean)

et al. 2023

View full text Add to dashboard Cite

We assessed the spatial variability in the size structure of phytoplankton, community composition, primary production and carbon fluxes through the planktonic food web of the Gulf of Gabès (GG; Southeastern Mediterranean Sea) in the fall of 2017 during the MERMEX-MERITE cruise. High concentrations in nutrients, chlorophyll a (2-6 µg L -1 ) and primary production (1816-3674 mg C m -2 d -1 ) revealed an eutrophic status of the studied stations in the GG. In accordance with hydrodynamic features, inorganic nutrients showed increases in concentrations from North to South and from coast to offshore, these nutrient gradients impacting the spatial distribution of phytoplankton community. Size-fractioned phytoplankton biomass and production were the lowest in the northernmost zone where they were mainly sustained by pico-sized fraction. Concomitantly, in this area, small aloricate ciliates were dominant leading to a high microbivory. Conversely, higher biomass and production were measured towards the South and offshore with prevalence of larger phytoplankton (nano-and/or micro-sized fractions) supported by diatoms. The herbivorous protozooplankton and metazooplankton were more abundant in these zones, resulting in an increase of the herbivory.The vertical particulate organic carbon flux followed also a north-south and coast-offshore increasing gradient, with a higher contribution of phytoplankton, and zooplankton fecal pellets to the sinking organic matter in the southernmost area. Our results suggest that even in nutrientrich and highly productive waters, a continuum of trophic pathways, ranging from microbial to multivorous and herbivorous food webs, may exist, which implies different efficiencies in carbon export and carrying capacity within the ecosystem.

show abstract

Temporal evolution of plankton and particles distribution across a mesoscale front during the spring bloom

Panaïotis,

Poteau,

Riquier

et al. 2024

Limnology & Oceanography

View full text Add to dashboard Cite

The effect of mesoscale features on the distribution of planktonic organisms are well documented. Yet, the interaction between these spatial features and the temporal scale, which can result in sudden increases of the planktonic biomass, is less known and not described at high resolution. A permanent mesoscale front in the Ligurian Sea (north‐western Mediterranean) was repeatedly sampled between January and June 2021 using a SeaExplorer glider equipped with an Underwater Vision Profiler 6 (UVP6), a versatile in situ imager. Both plankton and particle distributions were resolved throughout the spring bloom to assess whether the front was a location of increased zooplankton concentration and whether it constrained particle distribution. Over the 5 months, the glider performed more than 5000 dives and the UVP6 collected 1.1 million images. We focused our analysis on shallow (300 m) transects, which gave a horizontal resolution of 900 m. About 13,000 images of planktonic organisms were retained. Ordination methods applied to particles and plankton concentrations revealed strong temporal variations during the bloom, with a succession of various zooplankton communities. Changes in particle abundance and size could be explained by changes in the plankton community. The front had a strong influence on particle distribution, while the signal was not as clear for plankton, probably because of the relatively small number of imaged organisms. This work confirms the need to sample both plankton and particles at fine scale to understand their interactions, a task for which automated in situ imaging is particularly adapted.

show abstract

Primary Production in the Ligurian Sea

Cited by 5 publications

References 86 publications

Global sensitivity analysis of a one-dimensional ocean biogeochemical model

Global sensitivity analysis of a one-dimensional ocean biogeochemical model

Influence of Nutrient Gradient on Phytoplankton Size Structure, Primary Production and Carbon Transfer Pathway in a Highly Productive Area (SE Mediterranean)

Temporal evolution of plankton and particles distribution across a mesoscale front during the spring bloom

Contact Info

Product

Resources

About