MSc student wins best poster at oceanography conference

November 17, 2016
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Congratulations to MSc student Lian Kwong on winning Best Biological Oceanography Poster at the 2016 PICES Annual Meeting in San Diego, California.

Lian's poster entitled A Novel Approach to Estimating Active Carbon Flux Using the Biomass Size Spectra detailed her work on modelling the contribution of micronekton, the size classification of marine organisms between 2 – 10 cm, in transporting carbon vertically in the water column. Micronekton migrate to water near the ocean's surface during the day to feed on plankton, then return deeper to the mesopelagic zone at night. Natural processes including respiration, excretion, and death of the micronekton produces a net flux of carbon from the surface to the deeper ocean.

Prior attempts at modelling the contribution of various organisms' behaviour to this "active carbon pump" considered only the contribution of individual species or the flux resulting from particular processes. Lian instead quantifies the change in carbon flux of organisms in bulk by modelling metabolic processes according to organism size distribution. Depth stratified trawls from the waters off the southwest Coast of Oahu in 2004 provided Lian with a starting point of the quantity of organisms of different size fractions present. From there, Lian was able to model the quantity of carbon transported based on equations postulated within the literature dependent on organism size. The result is an all-inclusive picture of carbon transport to the deep ocean, and the surprise that previous estimates of carbon flux for may have underestimated the transport of carbon by zooplankton and micronekton by an order of magnitude. Combined with acoustic methods to more efficiently determine the regional size distribution and quantity of organisms present, Lian's model could provide enhanced predications of regional and global active carbon fluxes.

Lian is supervised by Professor Evgeny Pakhomov, who was recently appointed Director of the UBC Institute for the Oceans and Fisheries.