DBPapers
DOI: 10.5593/sgem2017/31/S15.110

INTENSITY, AREA EXTENT AND FREQUENCY OF COCCOLITHOPHORES EMILIANIA HUXLEYI BLOOMS IN THE BLACK SEA: APPLICATION OF REMOTE SENSING APPROACH

T. Churilova, S. Moncheva, V. Suslin, O. Kryvenko
Monday 11 September 2017 by Libadmin2017

References: 17th International Multidisciplinary Scientific GeoConference SGEM 2017, www.sgem.org, SGEM2017 Conference Proceedings, ISBN 978-619-7408-04-1 / ISSN 1314-2704, 29 June - 5 July, 2017, Vol. 17, Issue 31, 871-880 pp, DOI: 10.5593/sgem2017/31/S15.110

ABSTRACT

Detecting and monitoring of coccolithophores blooms is increasingly important due to their significant role in ocean biogeochemistry and unique capacity for feedbacks to climate because of calcite carbon and DMS production and high reflectance. Application of remote sensing approach, based on dependence of water optical properties on coccolithophores/coccoliths abundance (particulate back scattering coefficient) , allows for tracing of coccolithophores dynamics at basin-wide scale enabling quantification of bloom frequency and intensity in different subregions of the sea and evaluation of bloom extent area. A long-term data set of Emiliana huxleyi abundance in the north-western Black Sea was used for validation of the algorithm. The relationship between in situ measured E. huxleyi cell concentration and particles backscattering coefficient at 555 nm was applied for assessment of spatial-temporal distribution of E. huxleyi in the surface layer of the Black Sea from 1998 to 2016. To identify peak in E. huxleyi abundance (“blooms”) and assess inter-annual variability in “bloom” intensity we used normalized monthly and annual anomalies of E. huxleyi abundance. Remote detection of E. huxleyi abundance revealed differences in bloom frequency and mechanisms of occurrence between deep-water and shelf subregions. In deep-water habitat the “bloom” occurred once a year (in May-June). The “bloom” intensity and area extent were found to be inversely related to the upper mixed layer thickness that depended on the meteorological conditions of the previous winter. In shelf waters in addition to the spring-summer “bloom” a relatively high E. huxleyi abundance was observed also in cold period of the year with marked inter-annual variability in both intensity and time that could be attributed to a different combination of habitat properties and E. huxleyi traits.

Keywords: coccolithophores, bloom, remote sensing, seasonal and interannual variability, the Black Sea