{'fraction_non_alphanumeric': 0.04071661237785016, 'fraction_numerical': 0.04288816503800217, 'mean_word_length': 4.888178913738019, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Heterotrophic bacterial production in the eastern South Pacific: longitudinal trends and coupling with primary production

Spatial variations of heterotrophic bacterial production and phytoplankton primary production were investigated across South East Pacific Ocean (–141° W, –8° S to –72° W, –35° S) in November–December 2004. Bacterial production (³H leucine incorporation) integrated over the euphotic zone encompassed a wide range of values, from 43 mg C m-2 d-1 in the hyper-oligotrophic South Pacific Gyre to 392 mg C m-2 d-1 in the upwelling off Chile. Within the gyre (120° W, 22° S) records of low phytoplankton biomass (7 mg TChla m-2) were obtained and in situ 14C based particulate primary production rates were as low as 153 mg C m-2 d-1, thus equal to the value considered as a limit for primary production under strong oligotrophic conditions. In the South Pacific gyre average rates of ³H leucine incorporation rates, and leucine incorporation rates per cell (5–21 pmol L-1 h-1 and 15–56×10-21 mol cell-1 h-1, respectively), were in the same range as those reported for other oligotrophic sub tropical and temperate waters. Rates of dark community respiration, determined at selected stations across the transect varied in a narrow range (42–97 mmol O2 m-2 d-1), except for one station in the upwelling off Chile (245 mmol O2 m-2 d-1). Bacterial growth efficiencies varied between 5 and 38% and bacterial carbon demand largely exceeded 14C particulate primary production across the South Pacific Ocean. Net community production also revealed negative values in the South Pacific Gyre (–13±20 to –37±40 mmol O2 m-2 d-1). Such imbalances being impossible in this area far from any external input, we discuss the techniques involved for determining the coupling between primary production and bacterial heterotrophic production.