Paper in Press
JOURNAL OF GEOPHYSICAL RESEARCH, doi:10.1029/2011JC007342
Production and fate of transparent exopolymer particles in the ocean
- Particle aggregation in sea-surface microlayer high affecting light scattering
- Accumulation of gel-like particles (TEP) in near-surface water
- Conceptual model of TEP cycling known to be important to the light propagation
The production and fate of transparent exopolymer particles (TEP) has been investigated in various oceanic regions (tropical, temperate and polar), from the sea-surface microlayer (SML) to the deep ocean. Accumulation of TEP within the mixed layer was observed even in the absence of phytoplankton blooms, indicating abiotic processes are important in TEP production. The abiotic TEP aggregation rates measured in the tropical and temperate North Pacific and the Arctic Ocean averaged between 8 and 12 μmol C L^-1 day^-1. Depth profiles from under sea ice in the Arctic revealed the highest TEP concentrations, potentially released by sympagic algal activity at the bottom of the sea ice. The aggregation rates in the sea-surface microlayer (SML), the interfacial layer between the ocean and atmosphere, were generally enhanced over those in the bulk surface waters by factors of 2 to 30. This finding further strengthens a developing consensus on the gelatinous nature of the SML, which will also affect microbial life, light penetration and surface wave properties. We present a conceptual model implying that abiotic aggregation is an important factor for TEP production in the ocean, in particular in sea-surface microlayers, while consumption by zooplankton and protists recycle TEP, providing a new pool of dissolved precursor material. Overall, TEP is recycled within the water column through heterotrophic grazing and degradation, providing a new pool of TEP precursor materials, while enhanced aggregation rates of TEP in the SML indicates the importance of this thin surface film in the marine carbon cycle.
Received 6 June 2011; accepted 17 October 2011.
Citation: (2011), Production and fate of transparent exopolymer particles in the ocean, J. Geophys. Res., doi:10.1029/2011JC007342, in press.