Shifting Diatom-Dinoflagellate Dominance During Spring Bloom in the Baltic Sea and its Potential Effects on Biogeochemical Cycling
Laen...
Kuupäev
2018
Kättesaadav alates
Ajakirja pealkiri
Ajakirja ISSN
Köite pealkiri
Kirjastaja
Frontiers
Abstrakt
The Baltic Sea is affected by a range of human induced environmental pressures such
as eutrophication. Here we synthesize the ongoing shift from diatom dominance toward
more dinoflagellates in parts of the Baltic Sea during the spring bloom and its potential
effects on biogeochemical cycling of key elements (e.g., C, N, and P). The spring bloom
is the period with the highest annual primary production and sinking of organic matter to
the sediment. The fate of this organic matter is a key driver for material fluxes, affecting
ecosystem functioning and eutrophication feedback loops. The dominant diatoms and
dinoflagellates appear to be functionally surrogates as both groups are able to effectively
exhaust the wintertime accumulation of inorganic nutrients and produce bloom level
biomass that contribute to vertical export of organic matter. However, the groups have
very different sedimentation patterns, and the seafloor has variable potential to mineralize
the settled biomass in the different sub-basins. While diatoms sink quickly out of the
euphotic zone, dinoflagellates sink as inert resting cysts, or lyse in the water column
contributing to slowly settling phyto-detritus. The dominance by either phytoplankton
group thus directly affects both the summertime nutrient pools of the water column
and the input of organic matter to the sediment but to contrasting directions. The
proliferation of dinoflagellates with high encystment efficiency could increase sediment
retention and burial of organic matter, alleviating the eutrophication problem and improve
the environmental status of the Baltic Sea.
This study was supported by the Academy of Finland (decisions no 259164 and 263376) and Estonian Research Council (no 1575P, KO). Further funding came from Walter and Andrée de Nottbeck Foundation (KS and ToT) and the Swedish Cultural Heritage (ToT). LT acknowledges support also from COCOA— Nutrient cocktail in coastal zones of the Baltic Sea—EU BONUS project.
This study was supported by the Academy of Finland (decisions no 259164 and 263376) and Estonian Research Council (no 1575P, KO). Further funding came from Walter and Andrée de Nottbeck Foundation (KS and ToT) and the Swedish Cultural Heritage (ToT). LT acknowledges support also from COCOA— Nutrient cocktail in coastal zones of the Baltic Sea—EU BONUS project.
Kirjeldus
Märksõnad
eutrophication, pelagic-benthic coupling, ecosystem functioning, community composition, plankton sedimentation, carbon sink, articles