Multi-species okadaic acid contamination and human poisoning during a massive bloom of Dinophysis acuminata complex in southern Brazil

Publication date: November 2019Source: Harmful Algae, Volume 89Author(s): L.L. Mafra, P.K.W. Nolli, L.E. Mota, C. Domit, M. Soeth, L.F.G. Luz, B.F. Sobrinho, J.G. Leal, M. Di DomenicoAbstractOn June 2016, a major bloom of Dinophysis acuminata complex was noticed over the coast of Paraná State (PR), southern Brazil, an area unprotected by any official monitoring program. Here we report the results of an extensive sampling effort that ultimately led PR authorities to issue the first State shellfish-harvesting ban due to multi-species okadaic acid (OA) contamination. During its peak, the bloom covered an area of 201 km2 (∼2.0–3.5 × 54.0 km), attaining unprecedentedly high cell densities along the shallow (<15 m) continental shelf (mean 2.2 × 105, maximum 2.1 × 106 cells L−1) and adjacent sandy beaches (mean 2.8 × 105, maximum 5.2 × 106 cells L−1). Only OA was detected in suspension (max. 188 ng L−1). Toxin levels measured in bivalves were several times greater than the regulatory limit of 160 ng g−1, reaching up to 3600 ng g−1 in Crassostrea gasar, by far the highest OA concentrations ever reported in oysters worldwide, 7700 ng g−1 in brown mussels, Perna perna, and lower levels in clams, Anomalocardia brasiliana, and mangrove mussels, Mytella spp. Nine cases of human intoxication were officially reported and five people were hospitalized with typical symptoms of Diarrhetic Shellfish Poisoning linked to the consumption ...
Source: Harmful Algae - Category: Environmental Health Source Type: research