Toxic effects of harmful benthic dinoflagellate Ostreopsis ovata on invertebrate and vertebrate marine organisms

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• 作者：Marco Faimali^a ; ^{marco.faimali@ismar.cnr.it} ; Valentina Giussani^a ; ^b ; Veronica Piazza^a ; Francesca Garaventa^a ; Christian Corrà ; ^a ; Valentina Asnaghi^b ; Davide Privitera^b ; Lorenzo Gallus^b ; Riccardo Cattaneo-Vietti^b ; Luisa Mangialajo^c ; Mariachiara Chiantore^b
• 关键词：Ostreopsis ovata ; Toxicity ; Palytoxin ; Ecotoxicity bioassays
• 刊名：Marine Environmental Research
• 出版年：2012
• 期刊代码：51_01411136
• 类别：env
• 出版时间：May, 2012
• 卷：76
• 期：Complete
• 页码：97-107
• 文件大小：1083 K

摘要

Harmful benthic microalgae blooms are an emerging phenomenon causing health and economic concern, especially in tourist areas. This is the case of the Mediterranean Sea, where Ostreopsis ovata blooms occur in summer, with increasing regularity. Ostreopsis species produce palytoxin (PTX) and analogues, and a number of deaths directly associated with the ingestion of PTX contaminated seafood have been reported. PTX is considered one of the most toxic molecules occurring in nature and can provoke severe and sometimes lethal intoxications in humans. So far in temperate areas, O.聽ovata blooms were reported to cause intoxications of humans by inhalation and irritations by contact.

In addition, invertebrate mass mortalities have been reported, possibly linked to O.聽ovata blooms, although other causes cannot be ruled out, such as oxygen depletion or high seawater temperature. In order to improve our knowledge about the direct toxicity of this species on invertebrate and vertebrate marine organisms, we performed an ecotoxicological screening to investigate the toxic effects of different concentrations of O.聽ovata (cultured in the laboratory and sampled in the field during blooms) on crustaceans and fish as model organisms. Artemia salina, Tigriopus fulvus, and Amphibalanus amphitrite larvae and juveniles of the sea bass Dicentrarchus labrax were used as model species. Toxic effects associated with cultured O.聽ovata cells were investigated using a crossed design: testing two different temperatures (20 and 25 掳C), four different cell concentrations, and four treatments (untreated O.聽ovata culture, filtered and resuspended algal cells, growth medium devoid of algal cells, and sonicated algal cells). The results indicate that the toxicity of cultured O.聽ovata is related to the presence of living O.聽ovata cells, and that this effect is amplified by temperature. Furthermore, both tests with laboratory cultured algae and field sampled cells pointed out that A.聽salina is the most sensitive species even at concentrations below the Environmental Alarm Threshold set by the Italian Ministry of Health.

Some possible explanations of such sensitivity are discussed, taking into account evidence of O.聽ovata cells ingestion and the activity of its toxins on the Na⁺/K⁺-ATPase.