Macroalgae uses

Curonian Lagoon, Lithuania

Two species of red algae and over 13 species of green algae were found at 14 coastline stations of the Curonian Lagoon. Cladophora glomerata and Enteromorpha prolifera showed the widest distribution and the highest biomass (up to 1.69 and 2.22 kg DW/m², respectively) overgrowing stones, bunders, macrophytes, wooden or iron constructions. Low water transparency and limited suitable substrates for algae to attach determined their relatively low biomass.

Potential uses of macroalgae

The calorific value of C. glomerata and E. prolifera (10.1±4.0 and 12.4±2.0 MJ/kg accordingly) is similar to wood, but due to low biomass, macroalgae should be combined with other energy sources like reed. C. glomerata and E. prolifera accumulate 35.6±16.5 and 37.6±9.2 g/kg DW of nitrogen as well as 2.8±1.4 and 2.0±0.7 g/kg DW of phosphorus, thus are suitable to grow and harvest them seeking to reduce eutrophication of the Lagoon. Accumulation of heavy metals (Hg, Pb, Cd, Zn, Ni, Co, Cu, Cr) by the species do not exceed the permissible limits, so macroalgae may be used as fertilisers. For instance, macroalgae solutions of 0.1–0.3 mg/l increased L. sativum seeds germination up to 15%. The importance of macroalgae for the ecosystem functioning, their growth in the areas of nature protection and difficulty to access shore zone may limit the sustainable cultivation in the Lagoon. However, screening of macroalgae for high-value products and a smaller scale cultivation of particular species may be considered as well.