Multiscale biogeochemical fluxes and primary production monitoring across the intertidal-subtidal continuum in shallow coastal systems: the effect of physical forcing and climate change
PID2023-146617OB-I00 «Proyectos I+D+i» 2020 – Modalidad «Retos» y «Generación de conocimiento» // IP: Sokratis Papaspyrou /Irene Laiz (267.000 €)
Shallow coastal ecosystems are home to high biodiversity and provide an ample range of ecosystem functions and services. Their high productivity is partly due their high environmental variability and to the diversity of primary producers from phytoplankton to the benthic
microalgae (microphytobenthos, MPB) that inhabit the intertidal mudflats and photic subtidal areas. In some ecosystems, like the inner Bay of Cádiz (BoC), MPB shares the photic subtidal sediments with disperse seagrass and macroalgae meadows. These communities are distributed across the intertidal-subtidal continuum, in different ranges of sea level, and therefore under different physical forcing, mainly determined by the interaction between tides and photoperiod. In addition, the position of these biological communities along the intertidal subtidal continuum, likely make them to be affected differently by climate change, including extreme events like heat waves and strong winds, which will alter hydrodynamics, resuspended sediment load, temperature and light availability.
Despite the local and global importance of these ecosystems, the study of their ecological and biogeochemical functioning remains fragmented, with individual habitats and communities (intertidal, subtidal, bare sediment, seagrass meadows, etc) being studied independently, if at all, and in a non-spatially explicit form.
Consequently, whole system primary production, net metabolism and C and N biogeochemical cycling are not well quantified, nor is the effect of physical forcing on them at different spatiotemporal scales.
MULTIFLUX aims to integrate and quantify the biogeochemical
processes including benthic-pelagic coupling across different habitats and scales using the BoC as a case study by using cutting-edge scientific approaches and tools in an integrated manner.
More specifically, it will combine
1) laboratory experiments to address the effect of heat waves and simulated wind induced turbulence on MPB resuspension, net metabolism and the exchange of nutrients between the sediment and the water column;
2) in situ measurements of primary production and net metabolism using O2 microsensors, benthic chambers and a powerful novel technique, Aquatic Eddy Covariance (AEC), that allows integrating fluxes across larger spatiotemporal scales;
3) high spatial and temporal resolution monitoring of some physicochemical and biological variables (water and sediment temperature, grain size distribution, turbidity, currents, MPB and phytoplankton biomass, etc.) using a multiparametric buoy, drones (water and air) surveys and remote sensing; and
4) the development of a coupled physical-biological model, able to integrate at multiple scales the above mentioned variables and their interactions to forecast the impact of climate change on the BoC whole system productivity, with focus on MPB and phytoplankton.
By comprehensively studying the intertidal-subtidal continuum, this research will enhance our understanding, modelling capabilities, and predictions regarding the effects of physical forcing under normal and extreme climate conditions in the BoC. In addition to the scientific output, the resulting information and the physical-biological model will be valuable for the BoC Protected Natural Park and the Cadiz Port Authority. Besides, knowledge transfer will directly benefit two small-medium size enterprises. Finally, the international collaboration environment will be ideal to train a young researcher in coastal biogeochemistry and specifically in AEC.
Participants
National
Dr. S. Papaspyrou
Dra. I. Laiz
Dr. A. Corzo
Dr. M. Bethencourt
Dra. S. Haro (UMA)
Dr. CJ Gonzalez (HIM)
International
Dr. Ronnie Glud (Southern Denmark Univ., DK)
Dr. Karl Attard (Southern Denmark Univ., DK),
Dr. Vicente Le Fouest (Univ. la Rochelle, FRA)
Relevant previous results:
Haro, Sara; Bruno Jesus; S. Oiry; Sokratis Papaspyrou; Miguel Lara; Carlos José González; Alfonso Corzo. Microphytobenthos Spatio-Temporal Dynamics across an Intertidal Gradient Using Random Forest Classification and Sentinel-2 Imagery. Science of The Total Environment: 149983. 10.1016/j.scitotenv.2021.149983.
Carrasco Navas-Parejo, Juan Carlos; Alfonso Corzo, Sokratis Paspapyrou. Seasonal cycles of phytoplankton biomass and primary production in a tropical temporarily open-closed estuarine lagoon—The effect of an extreme climatic event. Science of the Total Environment. 723. 138014 10.1016/j.scitotenv.2020.138014
Haro, Sara; Miguel Lara, Carlos José González, Irene Laiz, Julio Bohórquez, Emilio García-Robledo, Alfonso Corzo and Sokratis Papaspyrou. (2020) Microbenthic metabolism and sediment biogeochemistry along the intertidal in the Cádiz Bay. Frontiers in Marine Science 7: 39, 3389/fmars.2020.00039v
