Santander, February 19th-22nd 2008 - Aranzadi

Of Shell and Sand: Coastal Habitat Availability and Human Foraging Strategies at Punta Candelero (Humacao, Puerto Rico)
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2. DATA AND RESULTS
The 2006 and 2007 archaeological intervention
at Punta Candelero, preceded development
plans for the area. Shells were recovered from the
sedimentary matrix of the archaeological deposit
using 6 mm and 3 mm mesh sieves (1 mm mesh
sieves were also used in some instances). No specific
shell midden or shell lens was identified, but
the shells were recovered from within the sediment.
Species identification was performed by
technician Edmarie Pagán in Puerto Rico. No additional
measurements were taken on the individual
shells, and no direct details were recorded on the
tabulated information, but the author did some preliminary
observations on the field and the laboratory
in Puerto Rico. The results (MNI/species, strata
and sieve size) were collated and analysed by
the author at the Institute of Archaeology,
University College London. Although hundreds of
terrestrial specimens were also collected and
identified, only the aquatic mollusca from the
archaeological strata are used in this study (see
Ramos-Vélez 2007 for details on the other faunal
remains). Only 2% of the shells recovered during
excavation were used at tools. The artefacts were
generally excluded from the analysis because,
being an object of workmanship, they could have
been specifically sourced from outside the area
and may not reflect local species availability.
The sample consists of 11,201 specimens of
Bivalvia and 7,230 specimens of Gastropoda;
most were identified to species level.
2.1. Bivalvia
Despite being more numerous than
Gastropods, Bivalves were less diverse (Table 1).
A total of 25 species were identified, but the
assemblage is overwhelmingly dominated by just
one genus: Donax (98.2% of the total) including
Donax denticulatus and Donax variabilis.
Most of the habitats documented for the
Bivalvia represent unconsolidated intertidal areas,
with occasional sea grass and other habitats in
very low percentages. Donax are infaunal inhabitants
of intertidal sandy environments and can be
found today in high density on the Island’s coasts.
In modern contexts, García (2005) indicates the
presence of up to 500 individuals per square
metre at the Humacao beach just north of the site.
Donax adults can reach 35mm, individuals
smaller than 6mm are very young. In Punta
Candelero, even though most of the individuals
(96%) were recovered from the 6mm sieve, 4% of
the sample passed through the 6mm mesh and
were trapped in the 3mm sieve. Even though individual
sizes were not recorded, the presence of
extremely small (and young) individuals suggests
size variability, which in turn can reflect the collection
method used. If individuals were hand-selected,
size uniformity would be expected with a bias
towards larger individuals (Gassiot-Balbè 2005).
The presence of small, very young individuals suggests
that these molluscs were collected en
masse, probably using some sort of sieve or basket.
Similar conclusions were drawn by Gassiot-
Balbè (2005) with his Donax sample from
Nicaragua.
The other bivalve species, such as Parvilucina
costata, Strigilla sp. and Tivela mactroides, are
infrequent and might have been collected incidentally
to the gathering of Donax. Species from
Thalassia beds, such as Anadara sp., Codakia sp.
and Purberella intapurpurea might represent
opportunistic gathering associated with trap setting.
The assemblage of Punta Candelero would
still need more detailed measurements on the individual
specimens to statistically support these
conclusions.
2.2. Gastropoda
A total of 59 Gastropoda species were identified
(Table 2). Nine species are dominant throughout the
strata: Lithopoma caelatum, Cittarium pica,
Fissurella nodosa, Nerita tessellata, Neritina clenchi,
Neritina virginea, Neritina punctulata, Tectarius
(Cenchritis) muricata and Turbo castanea. Of
these species, only one artefact of C. pica and one
of N. virginea were identified in Stratum A.
Otherwise, it seems that none of these species
were collected for making tools. The large number
of opercula, both in the 6 mm and the 3 mm sieve
size (but particularly on the 3 mm size), attest to
the collection of living specimens brought back to
the site for processing (Figure 5A).
Figure 5. A. Number of opercula by stratum and sieve size. B. Number of neritids
by species, stratum and sieve size.
MUNIBE Suplemento - Gehigarria 31, 2010
S.C. Aranzadi. Z.E. Donostia/San Sebastián