Several bacteria that are associated with macroalgae can use phycocolloids as a carbon source. Strain INACH002, isolated from decomposing Porphyra (Rhodophyta), in King George Island, Antarctica, was screened and characterized for the ability to produce agarase and alginate-lyase enzymatic activities. Our strain INACH002 was identified as a member of the genus Flavobacterium, closely related to Flavobacterium faecale, using 16S rRNA gene analysis. The INACH002 strain was characterized as psychrotrophic due to its optimal temperature (17°C) and maximum temperature (20°C) of growth. Agarase and alginate-lyase displayed enzymatic activities within a range of 10°C to 50°C, with differences in the optimal temperature to hydrolyze agar (50°C), agarose (50°C) and alginate (30°C) during the first 30 min of activity. Strain Flavobacterium INACH002 is a promising Antarctic biotechnological resource; however, further research is required to illustrate the structural and functional bases of the enzymatic performance observed during the degradation of different substrates at different temperatures.