Role of environmental conditions and physiology on the harmful impacts of Ostreopsis cf. ovata blooms

XIII Reunión Ibérica de Algas Tóxicas y Biotoxinas Marinas (REDIBAL 2018) - XIII Reunión Ibérica de Fitoplancton Tóxico - XIII Iberian Toxic Algae and Marine Biotoxins Meeting, VI Simposio Internacional de Ciencias del Mar - VI International Symposium of Marine Sciences (ISMS 2018), 20- 22 June 2018, Vigo.-- 2 pages

Temperature increases and man-assisted activities are favouring geographical expansion of tropical and subtropical marine species to higher latitudes. In the Mediterranean, one of the world places receiving most invasive species, the tropical genus Ostreopsis is detected, since the late 90s, in many beaches and in some of them it reaches huge abundances. Ostreopsis cf. ovata blooms have been related to different impacts on ecosystems and human health and wellbeing including massive mortalities of benthic fauna, mucilages covering benthic seaweeds, foams at surface, and respiratory irritations in people exposed to marine aerosols. However, the relationship between Ostreopsis blooms and respiratory irritations in humans is far to be direct because these symptoms are only detected in small periods of time during the proliferation. This paradox could be due to a multiple factors such as meteorological, environmental and Ostreopsis physiology. This led us to follow the blooms with an integrative approach, combining ecology, epidemiology and experiments along the bloom period. Surprisingly, first data analyses suggested that wind intensity and direction would play a minor role on the aerosol impacts. Thus, we studied how water motion could affect toxin synthesis. Ostreopsis cultures and natural communities from the hot spot were exposed during 1-3 weeks to either to calm or turbulence (generated by an orbital shaker simulating the wave motion). O. cf. ovata toxin production was four times higher in the stationary phase than in the exponential one, and populations exposed to turbulent conditions had 30% lower toxin content than the still cultures. The interplay between ecology and epidemiology has been crucial in determining this particular harmful pattern. Future citizen science activities will let us the opportunity to explore the potential respiratory symptoms in humans linked to Ostreopsis presence and/or blooms in new areas

Authors acknowledge the Spanish Government (MINECO) funded project OstreoRisk (CTM2014-53818-R) and the ERA-NET CoCliME project (CSIC Ref. OPE01531) funded by FORMAS (Sweden)

Peer Reviewed