Changes in marine resource consumption over the past 5000 years in southwestern Taiwan revealed by fish otoliths

Abstract

Coastal prehistoric settlement is a prominent topic in archaeology and is often associated with marine food supply for subsistence. In Taiwan and the tropical West Pacific area, early humans have relied on marine resources since the Palaeolithic period. However, in general, understanding past marine subsistence in Taiwan is impeded by scarce data on animal remains. This study investigated the change in fish consumption of prehistoric humans in southwest Taiwan over time using 1300 fish otoliths collected at archaeological sites in the Tainan Science Park. The investigated period was 5000 to 300 years ago, and two of the earliest currently-known Austronesian settlements in Taiwan, the Nankuanli and Nankuanli East sites, were included. In general, the abundance of otoliths declined over time. Our findings indicate that people of the Early and Late Neolithic preferred coastal fish, whereas people in the Iron Age preferred brackish and lagoonal fish. Fish assemblage was dominated by Larimichthys crocea (Richardson, 1846), and we use this species to compare the otolith size distribution through distinct periods. The comparison revealed an increase in fish size through time. We suggest that the changes in abundance and composition of the fish consumed by the prehistoric people were driven by the gradual seaward distancing of the shoreline, and the hypothesis that overfishing occurred in prehistoric southwestern Taiwan was rejected. Finally, the pronounced preference for the large yellow croaker may corroborate the theory of mainland-Chinese origins of the Austronesian speaking peoples.