Amino acids and hexosamines in water and pore water samples from different oceanic areas sampled between 2013 and 2016

These water and pore water samples were collected in different oceanic areas between 2013 and 2016. The samples were compiled from previous studies and used for statistical analyses in order to better understand particle dynamics and organic matter cycling in the ocean and to test and refine amino acid (AA) and hexosamine (HA) based biogeochemical indicators. Dissolved organic carbon (DOC) concentrations and total dissolved nitrogen (TDN) concentrations were determined with a POC-VCSH analyzer (Shimadzu) after removal of inorganic carbon by 2M HCl. Stable nitrogen and oxygen isotopes of nitrate (δ15N-NO3, δ18O-NO3) were analysed by the denitrifier method with a Delta Plus XP mass spectrometer. AA and HA contents and their individual monomers were analysed by liquid chromatography using a Biochrom 30 amino acid analyser after acid hydrolysis of filtered sea or pore water. Contents of AA and HA are presented in µmol/L and µg/L. AAC, AAN, HAC, HAN are presented in µg/L and as percentages of DOC (AAC/C, HAC/C) or TDN (AAN/N, HAN/N). AA and HA monomers are presented in Mol% and comprise aspartic acid (ASP), glutamic acid (Glu), threonine (Thr), serine (Ser), glycine (Gly), alanine (Ala), valine (Val), methionine (Met), isoleucine (Ile), leucine (Leu), tyrosine (Tyr), phenylalanine (Phe), β-Alanine (β-Ala), γ-aminobutyric acid (γ-Aba), histidine (His), ornithine (Orn), lysine (Lys) and arginine (Arg), glucosamine (GlcN) and galactosamine (GalN). Cysteic acid (CYA), taurine (TAU), methionine sulfoximine (MSO) and tryptophane (TRP) were determined only in the more recent samples. Data gaps indicate that measurements were not carried out or that they were not stored in the older data sets. The RI was calculated according to Jennerjahn and Ittekkot (1997; https://archimer.ifremer.fr/doc/00093/20403/) and the DI after Dauwe et al. (1999; doi:10.4319/lo.1999.44.7.1809). Definitions of biogeochemical indicators SDI, RTI, ox/anox and a detailed description of the methods can be found in Gaye et al. (2022; doi:org/10.5194/bg-19-807-2022).