Impacts of meltwater discharge from marine-terminating glaciers on the protist community in Inglefield Bredning, northwestern Greenland

• Published in: Marine ecology. Progress series (Halstenbek) 2020-05, Vol.642, p.55-65
• Main Authors: Matsuno, Kohei, Kanna, Naoya, Sugiyama, Shin, Yamaguchi, Atsushi, Yang, Eun Jin
• Format: Article
• Language: English
• Subjects: Abundance; Chlorophyll; Chlorophyll a; Ciliates; Diatoms; Dinoflagellata; Dinoflagellates; Discharge; Distribution; Fjords; Glaciers; Low temperature; Meltwater; Microorganisms; Mineral nutrients; Nutrients; Ocean circulation; Plankton; Primary production; Protists; Surface layers; Turbidity; Upwelling; Vertical distribution
• ISSN: 0171-8630; 1616-1599
• DOI: 10.3354/meps13324

To evaluate the effects of meltwater discharge from marine-terminating glaciers on a fjord protist community in northwestern Greenland during summer, we investigated the distribution, abundance and biomass of the protist community and their relationships with hydrographic parameters. In the standing stock of protists, dinoflagellates (46.4%) and oligotrich ciliates (39.5%) were dominant throughout the study region. With respect to vertical distribution, oligo - trich ciliates were abundant in the surface layer, mainly due to suitable food conditions (abundance of diatom and nanoflagellates). Near glaciers, relatively high chlorophyll a (chl a) concentrations were found in the subsurface layers associated with the low-temperature, high-turbidity and slightly high nutrient levels, indicating that the nutrient inputs from the upwelling glacialmeltwater plume increased primary production. Large-sized Protoperidium spp. were found only at stations near glaciers where nutrients were abundant, and heterotrophic dinoflagellates showed strong relationships with nanoflagellates. These findings suggest that the upwelling associated with subglacialmeltwater discharge can stimulate nanoflagellate production, resulting in increases in ciliate and heterotrophic dinoflagellate production.