Pelagic primary production in the coastal Mediterranean Sea: variability, trends, and contribution to basin-scale budgets

Abstract. We estimated pelagic primary production (PP) in the coastal (<200 m depth) Mediterranean Sea from satellite-borne data, its contribution to basin-scale carbon fixation, variability, and long-term trends during period 2002–2016. Annual PP was at 0.041 Gt C, which approximately represents 12 % of total fixation Sea. About 51 this occurs eastern basin, whereas western Adriatic shelves contribute with ?25 each production. Strong regional variability is revealed PP, high-production areas (>300 g C m?2) associated major river discharges less productive provinces (<50 located southeastern Mediterranean. dominated by interannual variations, but a notable decline (17 %) has been observed since 2012 concurring increasing sea surface temperatures positive North Atlantic Oscillation climate indices. Long-term reveal slight declines most (?0.05 ?0.1 m?2 per decade) except where increases +0.1 decade. Regionalization waters based on seasonal patterns reveals importance effluents determining that can regionally increase up 5-fold. Our study provides insight into balances while highlighting different temporal spatial scales variability.