Seaweeds have been consumed in Asia for centuries, and their value as healthy foods and sources of bioactive compounds is increasingly being rediscovered, particularly in Western countries. This growing interest is driving demand for biomass, fueled by emerging markets such as food and feed supplements, nutraceuticals, cosmeceuticals, and biomaterials. However, the risk of overexploitation of these natural resources, combined with the decline of wild populations due to climate change and anthropogenic pressures, highlights the urgent need for sustainable cultivation and effective conservation strategies.
Natural populations serve as reservoirs of genetic diversity, which is essential for both conservation efforts and the long-term sustainability of seaweed aquaculture. In particular, kelp species from the genera Laminaria and Saccharina are of high ecological importance, as they function as habitat-forming species, creating extensive marine forests that provide shelter and food for numerous organisms. Portugal lies within a biogeographical transition zone where many seaweed species, including cold-water kelps, reach their southern distribution limits.
This project aims to investigate how genetic diversity within kelp populations influences their adaptation to local environmental conditions and climate change. It is hypothesized that populations located at the edges of their distribution range may be locally adapted and potentially more resilient to increasing temperatures. The project will identify strains that are more adapted to local conditions for conservation aquaculture (e.g., higher reproductive output) and strains with desirable traits for commercial production (e.g., enhanced growth rates).
The study will focus on Saccharina latissima, which reaches its southern distribution limit in northern Portugal, and Laminaria ochroleuca, a more abundant but less-studied species located near the center of its distribution range. By studying their responses to environmental variables such as temperature and light, the project will assess their adaptive capacity and identify strains that perform well under unfavourable conditions. Key phenotypic traits related to growth, reproduction, and survival thresholds will be quantified to better understand adaptation strategies.
Given the heteromorphic life cycle of kelps, with alternation of microscopic haploid gametophytes and macroscopic diploid sporophytes, both life stages will be examined. This approach will provide a comprehensive assessment of population fitness and adaptation, particularly important for edge populations that may experience suboptimal conditions. Based on these findings, strains exhibiting superior adaptation and stress tolerance, while maintaining representative genetic diversity, will be selected for conservation and restoration efforts. For commercial aquaculture, priority will be given to strains with high growth rates and desirable biochemical composition, ensuring consistent yields and high-quality biomass.
These activities will be supported by the implementation of a biobank containing existing and newly collected wild strains of both species, along with associated genotypic and phenotypic data. This will involve extensive, non-destructive sampling of reproductive material. Strains will be maintained as gametophytes and made available to support future research, conservation initiatives, and aquaculture development.
Finally, selected high-performing strains will be tested under field conditions using restoration techniques based on different life cycle stages, including spores, laboratory-cultured gametophytes, and small sporophytes attached to culture substrates. Strains with strong commercial potential will be further evaluated in field cultivation trials.