Portugal has one of the largest exclusive economic zones of the world and a coastline of approximately 950 km, making its marine resources and aquaculture vital sectors for the Portuguese economy. The green macroalga Codium tomentosum is currently produced by the company ALGAplus in a land-based integrated multi-trophic aquaculture (IMTA) system and sold for human consumption (gourmet restaurants) and production of cosmeceuticals. This IMTA system integrates fish (e.g. sea bass and gilthead sea bream) and macroalgae (e.g. Codium, Porphyra, Ulva) aquaculture, using the nutrient-rich effluent water from fishponds to boost algal production. Due to the reduction of effluent nutrient loads, this is a more environmentally sound and sustainable option when compared to conventional aquaculture. While C. tomentosum holds a high-yield potential, their production is yet to be optimized. Large-scale cultivation of macroalgal biomass in open systems benefits from the low cost of using natural sunlight, but may encounter problems such as photoinhibition. While light is a paramount parameter for photosynthesis, high irradiance leads to the formation of reactive oxygen species (ROS) that damage the photosynthetic apparatus, hampering growth and reducing productivity.
In this project, C. tomentosum will be grown under different irradiances and variable conditions of light spectra (using neutral and different wavelength selective panels). The main objective of this proposal is to understand the effects of light quantity and quality in the growth/photosynthetic performance and in pigment, lipid and protein content of C. tomentosum in a land-based IMTA. The photoprotection mechanisms of macroalgae cultivated under different light conditions will be investigated in detail using various methodological approaches, combining ecophysiological (photosynthetic measurements using conventional and imaging fluorometry), biochemical (pigment analysis, protein quantification, enzymatic activity assays), and molecular (protein immunoblotting and transcriptomics) techniques. Biological material collected in the Portuguese coast will be compared with a domesticated variety produced at ALGAplus. The ultimate goal of the project is the optimization of light-use efficiency of C. tomentosum in open culturing tanks.

Members on this project

Ana Isabel Lillebø
Researcher

Ana Isabel Sousa
Researcher

Paulo Cartaxana
Coordinator

Ricardo Calado
Researcher

Sónia Cruz
Researcher