Quantifying harmful algal bloom thresholds for farmed salmon in southern Chile
| Autor: | Renato A. Quiñones, Ximena Rojas, Paulina Artacho, Rodrigo M. Montes, Alfredo Tello |
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| Rok vydání: | 2018 |
| Předmět: |
0106 biological sciences
Alexandrium catenella 010504 meteorology & atmospheric sciences Harmful Algal Bloom Fish farming Population Dynamics Aquaculture Plant Science Aquatic Science 01 natural sciences Algal bloom Algae Salmon Animals Marine ecosystem Chile Salmo 0105 earth and related environmental sciences geography geography.geographical_feature_category biology 010604 marine biology & hydrobiology Estuary biology.organism_classification Fishery Trout Dinoflagellida Linear Models Stramenopiles |
| Zdroj: | Harmful Algae. 77:55-65 |
| ISSN: | 1568-9883 |
| Popis: | Harmful algal blooms (HABs) have affected salmon farms in Chile since the early 1970's, causing massive losses in fish. Two large HABs occurred in 2002 and 2009, during which Alexandrium catenella blooms killed tons of salmon over an extended geographic area in southern Chile. At the beginning of 2016, high and persistent densities of Pseudochattonella cf. verruculosa and A. catenella were detected in the estuarine and marine ecosystems of southern Chile. Mortality for this latter event reached 27 million salmon and trout (i.e. 39,000 tons). Unfortunately, the threshold concentrations of algae that could be harmful to the health of farmed salmon in southern Chile have not yet been quantified. Here, to protect fish farms from HABs, critical concentration levels, i.e. thresholds at which the behavior of farmed Salmo salar is affected by harmful algae were quantified using generalized linear mixed models (GLMM). An extensive database from southern Chile covering the period from 1989 to 2016 was analyzed. The database included salmon behavior, cell abundance of microalgae and oceanographic factors. For both species analyzed, the higher the cell abundance, the greater the probability of detecting anomalous behavior. A threshold of 397 cells/mL was estimated for A. catenella, although it can increase up to ca.975 cells/mL at a Secchi depth6 m and up to 874 cells/mL during flood tide. A threshold value1 cell/mL for Pseudochattonella cf. verruculosa was found to be associated with anomalous salmon behavior, which significantly increased at a water temperature of 11 °C. Evidence for a relationship between fish behavior and mortality is provided. |
| Databáze: | OpenAIRE |
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