Declining spring production in the Barents Sea ice zone under climate forcing

Under anthropogenic forcing, Barents Sea greening and increased annual production are well-documented, yet seasonal differences in production trends are less clear. Here, using satellite ocean color data, we report a 45% decline in spring (April-May) primary production in the nitrate-limited Barents Sea ice zone between 1998 and 2023, corresponding to a reduction of 90.43 mg C m−2 day−1 per decade (p < 0.05). This decline is driven by reduced spring nitrate availability, resulting from slower winter nitrate replenishment rates, increased upstream consumption, and net nitrate export linked to Atlantification. Moreover, a North Atlantic-Arctic atmospheric wave train and reduced freshwater input have deepened the mixed layer, lowering light availability and further limiting production. These findings indicate that continued warming will likely suppress spring production in the Barents Sea ice zone, triggering nutrient-driven cascading effects on Arctic food webs and biodiversity. Barents Sea spring primary production has markedly declined over recent decades, driven by reduced nutrient and light availability, with potential implications for the stability of Arctic food webs and biodiversity.