Bloom dynamics of the newly described toxic benthic dinoflagellate Ostreopsis fattorussoi along the Lebanese coast (Eastern Mediterranean)

• Published in: Regional studies in marine science 2020-07, Vol.38, p.101338, Article 101338
• Main Authors: Açaf, Laury, Abboud-Abi Saab, Marie, Khoury-Hanna, Mirella, Lemée, Rodolphe
• Format: Article
• Language: English
• Subjects: Benthic HABs; Dinoflagellates; Eastern Mediterranean; Environmental Sciences; Lebanese coast; Microphytobenthos; Ostreopsis fattorussoi
• ISSN: 2352-4855; 2352-4855
• DOI: 10.1016/j.rsma.2020.101338

This study involves monitoring both benthic and planktonic abundances of the toxic dinoflagellate Ostreopsis fattorussoi in 5 stations along the Lebanese coast (Eastern Mediterranean); it extended from June 2014 to July 2016 and aims to study the dynamics of its development. Results revealed its presence year round along the coast, presenting seasonal blooms, both epiphytic and planktonic. A major bloom (maximum of 880 694 cells/g FW and 18 000 cells/L) occurred early in the summer (June–July), followed by a minor one in the fall (October–November) (≤ 50 000 cell/g FW). Its development seemed influenced by a combination of multiple environmental parameters. Water temperature seemed to play a major role in its development, as it appeared to be a thermophilic species, with maximum abundances per site reached between 27 °C and 30.5 °C. Its development could be facilitated by some agitation resulting from winds. Results concerning the role of nutrients and other environmental parameters remain inconclusive. •Seasonal blooms of Ostreopsis fattorussoi are observed along the Lebanese coast.•Its maximum abundance reached 880 694 cells/g FW and 18 000 cells/L.•Some degree of water turbulence and nitrate availability could facilitate blooms.•Water temperature plays a key role as O. fattorussoi appears to be thermophilic.