Biochemical composition and the contributions of hydrolysable particulate organic matter in the Ross Sea, Antarctic Ocean

Abstract

Water (<100 m) samples were collected from the Ross Sea (Antarctica) in late February to early March 2018, with the aim of investigating the spatial distribution of biochemical composition (proteins; PRT, carbohydrates; CHO, and lipids; LIP) and bioavailability of particulate organic matter (POM). Overall, the biochemical composition of POM was dominated by CHO, which accounted for 58.8% (SD = ± 12.8%) of total POM concentration, followed by PRT(21.0 ± 11.3%) and LIP (20.2 ± 9.7%). The particulated hydrolysable PRT (HPRT) ranged from below the detection limit 0 to 56.7 μg/L, hydrolysable CHO (HCHO) from 7.6 to 121.0 μg/L, and hydrolysable LIP (HLIP) from 7.0 to 86.6 μg/L, respectively. As a result, HPRT, HLIP, and HCHO accounted for 67.9%, 37.8%, and 64.6% of each compound, respectively. These results showed that PRT and CHO were largely used as sources of energy for higher trophic levels in the Ross Sea. .