Using bivalve chronologies for quantifying environmental drivers in a semi-enclosed temperate sea

Area of Science:

• Marine Paleoecology
• Paleoceanography
• Bivalve Shell Growth Analysis

Background:

• Bivalve shells offer valuable proxies for marine environmental variability, particularly at higher latitudes.
• Their utility in temperate, semi-enclosed seas like the Mediterranean is less explored.

Purpose of the Study:

• To develop and validate a bivalve shell chronology for tracking oceanographic processes in the Mediterranean.
• To investigate the relationship between Glycymeris pilosa growth and environmental factors in the Adriatic Sea.

Main Methods:

• Construction of a precisely dated chronology from Glycymeris pilosa shells (1979-2016).
• Statistical correlation analysis between the bivalve chronology and sea surface temperatures, and the Adriatic-Ionian Bimodal Oscillating System (BiOS) index.

Main Results:

• The chronology positively correlates with winter sea surface temperatures and negatively with summer temperatures.
• Strongest relationships observed were negative correlations with the BiOS index, indicating reduced growth during inflows of Eastern Mediterranean waters.
• No significant correlation found with freshwater discharge, highlighting the influence of remote oceanographic drivers.

Conclusions:

• Bivalve shell chronologies are effective tools for reconstructing oceanographic variability in temperate, semi-enclosed seas.
• Growth in Glycymeris pilosa is influenced by regional climate patterns (BiOS) and temperature extremes, rather than local freshwater inputs.
• This study demonstrates the potential of bivalve proxies for understanding past ocean circulation in mid-latitude systems.