Succession and fate of the spring diatom bloom in Disko Bay, western Greenland

Marine Ecology Progress Series

Morten Hjorth¹  Kristine Engel Arendt¹  Michael D#xfcnweber¹  Torkel Gissel Nielsen¹  Sanne Kjellerup¹  Kajsa T#xf6nnesson¹  Eva Friis M#xf8ller¹  Rasmus Swalethorp¹ 

关键词: Spring bloom;    Calanus spp.;    Grazing;    Faecal pellets;    Sedimentation;    Arctic;    Greenland;   

DOI  :  10.3354/meps08813

学科分类：海洋学与技术

来源: Inter-Research

【 摘 要 】

ABSTRACT: Phytoplankton and copepod succession was investigated in Disko Bay, western Greenland from February to July 2008. The spring phytoplankton bloom developed immediately after the breakup of sea ice and reached a peak concentration of 24 mg chl a m^–3 2 wk later. The bloom was analyzed during 3 phases: the developing, the decaying, and the post-bloom phases. Grazing impact by the copepod community was assessed by 4 methods; gut fluorescence, in situ faecal pellet production, and egg and faecal pellet production from bottle incubations. Calanus spp. dominated the mesozooplankton community. They were present from the initiation of the bloom but only had a small grazing impact on the phytoplankton. Consequently, there was a close coupling between the spring phytoplankton bloom and sedimentation of particulate organic carbon (POC). Out of 1836 ± 180 mg C m^–2 d^–1 leaving the upper 50 m, 60% was phytoplankton based carbon (PPC). The composition and quality of the sedimenting material changed throughout the bloom succession from PPC dominance in the initial phase with a POC/PON ratio close to 6.6 to a dominance of amorphous detritus with a higher POC/PON ratio (>10) in the post-bloom phase. The succession and fate of the phytoplankton spring bloom was controlled by nitrogen limitation and subsequent sedimentation, while grazing-mediated flux by the Calanus-dominated copepod community played a minor role in the termination of the spring bloom of Disko Bay.

【 授权许可】

Unknown