Relationship between Essential Fatty Acid Composition of Sediments and Species Richness of Benthic Animals in Paddy Field Ecosystems

Abstract

Essential fatty acids (EFAs) are used as an indicator of food source quality for animals. However, it is not clear whether the EFA composition of food sources is a good indicator of the abundance and richness of animals in ecosystems. In this study, field surveys of paddy fields were conducted to clarify the relationship between benthic animals and the EFA composition of sediment as a potential food source for those animals. We investigated sediment and benthic animals in several paddy fields in Miyagi prefecture from 2009 to 2011. We analyzed the EFA composition and Chl-a in sediment and identified the benthic animals present. We found a positive relationship (p < 0.05) between the concentration of 20:5ω3 in sediment and the number of families of benthic animals. It was considered that diatoms, widely known to be a producer of 20:5ω3, are diversity marker of benthic animals in paddy fields.