# Assessment of the Resource Potential of Baltic Sea Macroalgae
## 3 Results
### Seasonal Dynamics of Beach-Cast Macroalgae
Figure 3: Taxonomic representation in beach-cast algae from Filinsky Bay in different seasons: 1—_Furcellaria_, 2—_Polysiphonia_, 3—_Cladophora_, 4—_Ulva_, 5—_Fucus_, 6—Others. The highest carbohydrate content in the biomass of the red algae _Furcellaria_ and _Polysiphonia_ was related to the differences in their development. These algae are perennial, while green algae are seasonal (vegetation period 3-6 months) and do not have a thick cell wall, resulting in a lower carbohydrate content in the biomass (_Ulva_ sp. 11.83% and _Cladophora_ 13.04%). Fucose, glucose, and galactose dominated among carbohydrates. Arabinoses were abundant only in the biomass of _Ulva_ sp. samples. The content of cellulose in the biomass of algae was approximately the same and varied in the range of 2.14-4.63%. The highest total lipid content was found in macroalgae samples from the genus _Furcellaria_, accounting for 4.3% of total dry biomass. The total lipid content in _Cladophora_ algae samples was 2.8% (Table 3). The lipid content of macroalgae from the genus _Ulva_ sp. was 2.4% of the total biomass. The algae of the genus _Polysiphonia_ had the lowest lipid content (2.3%). The original HPLC data are presented in Supplementary Materials. The next stage of research was focused on determining the fatty acid composition of lipids found in drifting algae in order to assess their potential for use in the nutraceuticalital, pharmaceutical, and cosmetic industries. The results of the HPLC analysis are presented in Table 5. \begin{table}
\begin{tabular}{l c c c c} \hline \hline \multirow{2}{*}{**Component**} & \multicolumn{4}{c}{**Content, \%**} \\ \cline{2-5}  & _Ulva_ & _Cladophora_ & _Polysiphonia_ & _Furcellaria_ \\ \hline Glucose & 4.51 \(\pm\) 0.13 & 1.63 \(\pm\) 0.04 & 2.31 \(\pm\) 0.07 & 1.73 \(\pm\) 0.04 \\ Xylose & 1.10 \(\pm\) 0.03 & 0.69 \(\pm\) 0.01 & 0.34 \(\pm\) 0.01 & 0.44 \(\pm\) 0.01 \\ Fucose & 2.32 \(\pm\) 0.07 & 2.71 \(\pm\) 0.10 & 4.13 \(\pm\) 0.10 & 6.49 \(\pm\) 0.10 \\ Arabinose & 1.24 \(\pm\) 0.06 & 3.38 \(\pm\) 0.08 & 0.64 \(\pm\) 0.01 & 0.43 \(\pm\) 0.02 \\ Rhamose & 0.39 \(\pm\) 0.01 & 1.22 \(\pm\) 0.03 & 0.37 \(\pm\) 0.01 & 0.32 \(\pm\) 0.01 \\ Galactose & 1.66 \(\pm\) 0.04 & 1.85 \(\pm\) 0.05 & 1.18 \(\pm\) 0.03 & 2.51 \(\pm\) 0.08 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Carbohydrate composition of macroalgae (% of the content of reducing carbohydrates). \begin{table}
\begin{tabular}{l c c c c} \hline \hline \multirow{2}{*}{**Indicator**} & \multicolumn{4}{c}{**Content, \% of Absolute Dry Matter**} \\ \cline{2-5}  & _Cladophora_ & _Polysiphonia_ & _Ulva sp._ & _Furcellaria_ \\ \hline Protein (Kjeldahl) & 20.8 \(\pm\) 0.62 & 28.2 \(\pm\) 0.84 & 17.3 \(\pm\) 0.52 & 25.4 \(\pm\) 0.76 \\ Protein (Bradford) & 3.1 \(\pm\) 0.1 & 3.1 \(\pm\) 0.1 & 2.8 \(\pm\) 0.1 & 3.5 \(\pm\) 0.1 \\ Reducing sugars & 13.04 \(\pm\) 0.39 & 17.84 \(\pm\) 0.53 & 11.83 \(\pm\) 0.35 & 21.96 \(\pm\) 0.65 \\ Cellulose & 4.63 \(\pm\) 0.12 & 2.14 \(\pm\) 0.06 & 2.14 \(\pm\) 0.08 & 3.67 \(\pm\) 0.11 \\ Carbohydrate (total) & 17.67 \(\pm\) 0.51 & 19.98 \(\pm\) 0.59 & 13.97 \(\pm\) 0.43 & 25.63 \(\pm\) 0.76 \\ Carbohydrate (total) according to the literature data & 34.7 [58] & 25.8 [59] & 31.34-45.5 & 55.4 [63, 64] \\ Lipids & 2.8 \(\pm\) 0.1 & 2.3 \(\pm\) 0.1 & 2.4 \(\pm\) 0.1 & 4.3 \(\pm\) 0.1 \\ \hline The ratio of proteins and carbohydrates & 1.18:1 & 1.41:1 & 1.24:1 & 1:1 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Content of crude protein, lipids, and carbohydrates in macroalgae samples.