The living and the dead: How do taphonomic processes modify relative abundance and skeletal completeness of freshwater fish?

This study is designed to determine the extent to which taphonomic processes alter the taxonomic composition of fish remains in lacustrine sediments. We wish to explore information loss in a bone assemblage relative to the original, living community. We examined fish bone assemblages from lacustrine sediments along the southern shore of Lake Kinneret (Sea of Galilee) and compared them to modern living communities. For this purpose we randomly selected 24 squares, each 0.5 m2 in size, and excavated them to a depth of 30–50 cm. Three lithofacies were recovered, spanning the past 1500 years (unccorected for reservoir age). The fish remains include 5037 bones and 758 scales, of which 1566 bones were identified to taxonomic group. The list of identified species was compared with the list of indigenous species known to live in Lake Kinneret in general and in a similar sandy habitat in particular. The proportion of skeletal elements found was compared with the proportion known in a complete fish. Our study indicates that differences exist between the three lithofacies in species diversity and composition, skeletal element richness, completeness, and relative abundance. In addition, the bones exhibit a clumped distribution pattern, regardless of depositional depth. From a taphonomic and paleoecological perspective, our findings demonstrate that fish remains retrieved from lacustrine sediments do not represent the composition and diversity of species as in the recent fish community.