Shells and Humans: Molluscs and Other Coastal Resources from the Earliest Human Occupations at the Mesolithic Shell Midden of El Mazo (Asturias, Northern Spain)

Abstract

Human populations exploited coastal areas with intensity during the Mesolithic in Atlantic Europe, resulting in the accumulation of large shell middens. Northern Spain is one of the most prolific regions, and especially the so-called Asturian area. Large accumulations of shellfish led some scholars to propose the existence of intensification in the exploitation of coastal resources in the region during the Mesolithic. In this paper, shell remains (molluscs, crustaceans and echinoderms) from stratigraphic units 114 and 115 (dated to the early Mesolithic c. 9 kys cal BP) at El Mazo cave (Asturias, northern Spain) were studied in order to establish resource exploitation patterns and environmental conditions. Species representation showed that limpets, top shells and sea urchins were preferentially exploited. One-millimetre mesh screens were crucial in establishing an accurate minimum number of individuals for sea urchins and to determine their importance in exploitation patterns. Environmental conditions deduced from shell assemblages indicated that temperate conditions prevailed at the time of the occupation and the morphology of the coastline was similar to today (rocky exposed shores). Information recovered relating to species representation, collection areas and shell biometry reflected some evidence of intensification (reduced shell size, collection in lower areas of exposed shores, no size selection in some units and species) in the exploitation of coastal resources through time. However, the results suggested the existence of changes in collection strategies and resource management, and periods of intense shell collection may have alternated with times of shell stock recovery throughout the Mesolithic.

Last Interglacial Iberian Neandertals as fisher-hunter-gatherers

“…194,500 (unit 114) and 184,900 (unit 115), more than twice the 91,636 found in unit 108 (173,174). Site structure may explain the deviation, at least in part, as the samples come from a peripheral area of the site and reflect how dense shell can be in well-preserved refuse dumps; if post-depositional processes had resulted in their scattering across the 100 m² of El Mazo's sheltered area, the overall density of the remains would have been averaged out and, at any given point of sampling, much lower (and the attendant breakage would make for significantly diminished specimen counts).…”

Marine Snails of the Genus Phorcus: Biology and Ecology of Sentinel Species for Human Impacts on the Rocky Shores

“…The more abundant species adapted to cold water, such as the periwinkle Littorina littorea (Linnaeus, 1758) and the limpet Patella vulgata (Linnaeus, 1758) in the late Pleistocene, were replaced by species better suited to warmer conditions such as P. lineatus, Patella depressa Pennant, 1777, and P. ulyssiponensis in the Holocene [81,82]. A similar pattern is visible today in the Cantabrian coast, with a predominance of warmer species such as P. lineatus and the absence of L. littorea [53].…”

“…Hunter-gatherers have exploited intertidal grazers, since prehistoric times, and there are evidences that the densities and the maximum sizes of several species were reduced by the exploitation [51,52]. Studies performed in Northern Spain showed that topshells and limpets were collected, at subsistence exploitation levels, from intertidal areas of exposed shores, leading to the formation of huge shell middens [53]. In fact, intertidal resources have always been collected by humans as food supplement or used as a bargaining chip with other products worldwide [54,55].…”

Mg/Ca profiles within archaeological mollusc (Patella vulgata) shells: Laser-Induced Breakdown Spectroscopy compared to Inductively Coupled Plasma-Optical Emission Spectrometry

“…Elemental ratios in P. vulgata marine mollusc shells are typically measured in the calcite m+2 shell layer [9,36,37], because that part of the shell covers most of the mollusc's lifespan with high shell deposition rates, resulting in a long section that enables high temporal resolution measurements. The m-2 calcite layer located near the P. vulgata shell apex is now shown to preserve the same Mg/Ca record [25], but is compressed into a thickness of only a few millimetres.…”