NEAR-DAILY RECONSTRUCTION OF TROPICAL INTERTIDAL SEA-SURFACE TEMPERATURE FROM LIMPET SHELLS TO INFER THEIR GROWTH RATES

Measurements of life-history traits can reflect an organism's response to environmental factors.

In  wave-dominated rocky intertidal ecosystems, measurements of key grazing invertebrates are constrained by extreme conditions. Recent research demonstrates mollusc shells to be high-resolution oceanographic climate proxies for SST as well as archival records of growth; however, no prior molluscan climate proxy has been demonstrated for the tropical rocky intertidal environment - a zone influenced by warmer waters, mixed tides, trade-wind patterns, and wave-action.

Here, we show the first near-daily, spatiotemporal climate proxy for SST in the tropical rocky intertidal environment by coupling secondary ion mass spectrometry analysis of oxygen isotopes with the sclerochronology of Cellana sandwicensis , an endemic Hawaiian intertidal limpet, that is a significant biocultural resource harvested for consumption. We also develop a method for reliable interpretation of seasonal growth patterns and longevity in limpets.

This study provides a robust approach to explore tropical intertidal temperature climatology and molluscan life-history.