Optimization of sampling, cell collection and counting for the monitoring of benthic harmful algal blooms: Application to Ostreopsis spp. blooms in the Mediterranean Sea

TOTTI, CECILIA; ABBOUD-ABI SAAB, MARIE; ASNAGHI, VALENTINA; JAUZEIN, CÉCILE; LEMÉE, RODOLPHE; MANGIALAJO, LUISA; HACHANI, MOHAMED AMINE; ACCORONI, STEFANO; ZAGHMOURI, IMEN; CHIANTORE, MARIACHIARA; FRICKE, ANNA; AÇAF, LAURY

ECOLOGICAL INDICATORS

ELSEVIER SCIENCE BV

Año: 2018 vol. 91 p. 116 - 127

1470-160X

Toxic blooms of Ostreopsis spp. are greatly challenging to monitor due to the complexity and variability of cellrepartition among benthic and pelagic compartments. This results in marked differences in employed methodologiesfor the survey of their dynamics and hampers the definition of the associated toxic risk. The presentstudy aims at testing and improving common methodologies used for sampling, processing and counting of fieldsamples. It contributes to the identification of the most suitable strategies for the monitoring and mitigation ofOstreopsis blooms in coastal waters. For a sampling based on the collection of macrophytes, the role of thefixative addition and of agitation steps in the efficiency of epiphytic cell collection was defined. For planktonicestimations, the influence of the volume used for concentrating water samples was characterized as a function ofOstreopsis cell abundance. The deployment of artificial substrates was tested and confirmed strong advantages ofthis new sampling methodology, including an integration of a part of the spatial and temporal variability of thecell distribution.