Trends in Ostreopsis proliferation along the Northern Mediterranean coasts

Abstract

Harmful benthic microalgae blooms represent an emergent phenomenon in temperate zones, causing health, ecological and economic concern. The main goal of this work was to compile records of Ostreopsis at large temporal and spatial scales, in order to study the relationship between cell abundances, the periodicity and intensity of the blooms and the role of sea water temperature in 14 Spanish, French, Monegasque and Italian sites located along the northern limits of the Mediterranean Sea. General trends were observed in the two considered basins: the north-western Mediterranean Sea, in which higher cell abundances were mostly recorded in mid-summer (end of July), and the northern Adriatic Sea where they occur in early fall (end of September). The sea-water temperature does not seem to be a primary driver, and the maximal abundance periods were site and year specific. Such results represent an important step in the understanding of harmful benthic microalgae blooms in temperate areas, and provide a good base for policy makers and managers in the attempt to monitor and forecast benthic harmful microalgae blooms.

Establishing the link between <em>Ostreopsis</em> cf.<em>ovata</em> blooms and human health impacts using ecology and epidemiology

“…In 2013, the Ostreopsis bloom exhibited the typical seasonal pattern described earlier in Sant Andreu de Llavaneres (Mangialajo et al 2011, Vila et al 2012a. The meteorology conditions during the summer-autumn season fitted within the general climatology described in the area.…”

“…Overall, cell abundances were in the range reported elsewhere in the area (e.g. Mangialajo et al 2011, Vila et al 2012a. The epiphytic Ostreopsis cf.…”

“…10 m distance), there is an indoor-outdoor restaurant whose entire staff was selected as the human cohort for our study. The ecological and epidemiological study period extended from 1 June to 1 December 2013, because our former studies in this area (Vila et al 2008, Vila et al 2012b, Mangialajo et al 2011 had shown the seasonality of the Ostreopsis bloom during the summer-autumn period.…”

“…This microalga of tropical origin that produces palytoxin (PLTX; Rossi et al 2010) and associated analogues has been blooming recurrently at some locations in the Mediterranean during the last 20 years (e.g. Vila et al 2001, Aligizaki and Nikolaidis 2006, Mangialajo et al 2011. Its presence was previously detected in tropical and temperate coasts of Australia, the Indian Ocean, eastern Asian, the Caribbean sea, Brazil and, in the last decade, in colder waters of the northern Sea of Japan, New Zealand, Portugal, the Atlantic coasts of France and Spain (e.g.…”

“…In the NW Mediterranean, various studies have been conducted on Sant Andreu de Llavaneres beach (41°33.13′N; 2°29.54′E), which is an Ostreopsis hot spot where annual blooms have been occurring in the last few decades (Mangialajo et al 2011, Vila et al 2012a. At this station, O. cf.…”