Bivalvos como indicadores de variabilidad interanual de la temperatura en el Transecto de Kola (Mar de Barents)

The Barents Sea, a hotspot for rapid Arctic warming, requires reliable bioindicators to monitor ecological variability. This study investigated the potential of bivalve mollusks as indicators of short-term warming by analyzing their communities along the Kola Transect in the southern Barents Sea in 2015 and 2019, years preceded by differing intensities of warming. We identified clear latitudinal gradients, with diversity, abundance, and biomass decreasing northward, correlated with increasing depth. The warmer pre-2019 period triggered a significant community reassembly, marked by increased abundance of boreal-Arctic deposit feeders (Mendicula ferruginosa, Yoldiella nana, Thyasira gouldi) and declines in the colder-water species Parathyasira equalis and the suspension feeder Bathyarca pectunculoides. Redundancy analysis showed that community structure was primarily driven by depth (explaining 32% of abundance and 28% of biomass variation) and the preceding sea surface temperature trend (explaining 20% of abundance variation). The observed shifts indicate a move toward a depauperate, dominance-driven community under warming, favoring detritivory. We propose a specific bioindicator framework, including sentinel species and a "bivalve borealization index" for monitoring climate-driven variability.