Marine Resources in the Mesolithic and Neolithic at the Grotta Dell’uzzo (Sicily): Evidence From Isotope Analyses of Marine Shells*

Abstract

Oxygen isotopes in shell carbonate samples from the marine rocky-shore intertidal gastropod Monodonta turbinata (Born) are investigated in both modern analogue specimens and in archaeological specimens from the Grotta dell'Uzzo (Sicily). Variations in shell edge values of δ 18 O in living specimens collected monthly over two years are closely correlated with monthly seawater temperatures measured at the time of collection, showing that the species can be used for palaeoseasonality studies. Analyses of shell edge δ 18 O values in archaeological specimens, from Mesolithic through to early Neolithic phases at the Grotta dell'Uzzo, enabled the inference of various seasons of collection of shellfish and how such seasonality varies between the different phases of occupation. Interesting similarities and differences exist between the seasons of marine shellfish exploitation and the seasons inferred from the vertebrate zooarchaeological assemblages. A major inference drawn from the analyses and discussion is that the exploitation of all marine resources (fish and shellfish) increased in the later Mesolithic and early Neolithic periods.

Mesolithic shellfish exploitation in SW Italy: seasonal evidence from the oxygen isotopic composition of Osilinus turbinatus shells

“…To ensure comparable results with other studies, sample procedures follow Mannino et al (2007Mannino et al ( , 2008 for O. turbinatus from the Sicilian coast. A single carbonate sample of the inner nacreous layer was taken from the ultimate growth increment (shell-edge) of modern specimens by using a manual microdrill with a 0.5 mm bit (Fig.…”

“…Poppe and Goto, 1991), and shell growth checks might not provide reliable markers of ontogenic age (Mannino et al, 2008). Since medium shells provide sufficient calcium carbonate relative to the last growth year to be sampled for seasonal studies (Mannino et al, 2007), medium shells of almost similar size were selected (20-24 mm width).…”

“…Schö ne et al, 2007 and references therein), shell growth rate decrease with ontogenetic age (Mannino et al, 2008). (Schifano and Censi, 1983;Mannino et al, 2008), thus emphasizing their potential suitability for the study of seasonal shellfish exploitation in prehistoric sites (Mannino et al, 2007 During each collection period, surface sea water temperature was measured. Mean monthly sea surface salinity (SSS) for this area was obtained from the European Project ''Mediterranean ocean forecasting system: toward environmental predictions (MFSTEP)'' (http://www.bo.ingv.it/mfstep).…”

“…Martini et al, 2007a), comprehensive information about their temporal exploitation patterns is scarce (Mannino et al, 2007) and emphasize the necessity of more regional data. A proven approach to investigate temporal patterns of prehistoric shellfish exploitation is the analysis of the oxygen isotopic ratio (d 18 O) of the latest growth increment of mollusc shells (e.g.…”

“…A proven approach to investigate temporal patterns of prehistoric shellfish exploitation is the analysis of the oxygen isotopic ratio (d 18 O) of the latest growth increment of mollusc shells (e.g. Kennett and Voorhies, 1996;Quitmyer et al, 1997;Mannino et al, 2003Mannino et al, , 2007Jones et al, 2008). This is based on the fact that the d…”