Scientists Discover Potentially New Algae Species in the Kuril Islands

Seaweed communities on Kunashir Island are undergoing a structural shift driven by rising ocean temperatures. During an expedition from September 6 to 15, phycologists from Vladivostok surveyed the littoral and upper sublittoral zones—down to a depth of two meters—finding that shifting thermal regimes are altering the region's floral composition. The transformation is propelled by the Tsushima Current and its Soya branch, which transport warm waters and southern species toward the Okhotsk coasts of Kunashir and Iturup. This process operates through two simultaneous vectors: the expansion of thermophilic southern algae and the degradation of cold-water species. The decline of cold-adapted flora is already evident in the reduced biomass of brown laminarians on Moneron and the Commander Islands. The loss of laminarian forests, such as the Japanese Saccharina, removes the primary physical architecture of the seabed. These forests serve as critical shelters and feeding grounds for hundreds of marine organisms; their disappearance threatens the overall biological productivity of the Sea of Okhotsk.