Seasonal dynamics of sinking organic matter in the Pacific Arctic Ocean revealed by nitrogen isotope ratios of amino acids
Choi, Hyuntae et al. (2022), Seasonal dynamics of sinking organic matter in the Pacific Arctic Ocean revealed by nitrogen isotope ratios of amino acids, Dryad, Dataset, https://doi.org/10.5061/dryad.cvdncjt54
Biological sources of organic matter in sinking particles were investigated using nitrogen isotope analysis of amino acids in the Pacific Arctic Ocean, which has experienced a rapidly changing climate, sea-ice retreat, and enhanced primary production over the past few decades. The average trophic position based on differences in the nitrogen isotope ratios of glutamic acid and phenylalanine indicates the relative proportions of photoautotrophs and heterotrophs in sinking particles. Decreasing values (close to 1.0) in summer suggest that primary producers are responsible for most of the downward flux of sinking particles. However, the average trophic position increased to greater than 1.5 in September and was maintained at approximately 1.8 during ice-covered winter periods, likely due to greater contributions from heterotrophic organisms in microbial communities. The average trophic position in sinking particles should reflect the seasonal dynamics of microbial community structure in the Pacific Arctic Ocean.
Ministry of Oceans and Fisheries, Award: 1525011760