Brazilian shellmounds are archaeological sites with a high concentration of
marine faunal remains. There are more than 2000 sites along the coast of Brazil
that range in age from 8,720 to 985 cal BP. Here, we studied the
ichthyoarchaeological remains (i.e., cranial/postcranial bones, otoliths, and
teeth, among others) at 13 shellmounds on the southern coast of the state of Rio
de Janeiro, which are located in coastal landscapes, including a sandy plain
with coastal lagoons, rocky islands, islets and rocky bays. We identified
patterns of similarity between shellmounds based on fish diversity, the ages of
the assemblages, littoral geomorphology and prehistoric fisheries. Our new
radiocarbon dating, based on otolith samples, was used for fishery
characterization over time. A taxonomical study of the ichthyoarchaeological
remains includes a diversity of 97 marine species, representing 37% of all
modern species (i.e., 265 spp.) that have been documented along the coast of Rio
de Janeiro state. This high fish diversity recovered from the shellmounds is
clear evidence of well-developed prehistoric fishery activity that targeted
sharks, rays and finfishes in a productive area influenced by coastal marine
upwelling. The presence of adult and neonate shark, especially oceanic species,
is here interpreted as evidence of prehistoric fisheries capacity for
exploitation and possibly overexploitation in nursery areas. Various tools and
strategies were used to capture finfish in seasonal fisheries, over rocky reef
bottoms and in sandy littoral environments. Massive catches of whitemouth
croaker, main target dermersal species of South Atlantic coast, show evidence of
a reduction in body size of approximately 28% compared with modern fisheries.
Fishery activity involving vulnerable species, especially in nursery areas,
could mark the beginning of fish depletion along the southeastern Brazilian
coast and the collapse of natural fish populations.