Articles scientifiques
X.A. Alvarez-Salgado, U. Labarta, M.J. Fernández-Reiriz, F.G. Figueiras, G. Rosón, S. Piedracoba, R. Filgueira, and J.M. Cabanas (2008)
Renewal time and the impact of harmful algal blooms on the extensive mussel raft culture of the Iberian coastal upwelling system (SW Europe)
Harmful Algae, 7(6):849-855.
The extension and intensity of the upwelling season in the NW Iberian Peninsula (42°N-43°N) have decreased by 30 and 45\% over the last 40 years, respectively. Accordingly, the renewal time ([tau]) of the Rías Baixas, four large coastal inlets where 15\% of the World extraction of blue mussels occurs, has increased by 240\%. We indirectly demonstrate here that the growing [tau] has caused the increasing occurrence of harmful microalgae in these embayments, dramatically affecting mussel raft cultivation. The equation D = 365(1 - exp(-[tau]/c1)) explains 80\% of the variability of the number of days per year that mussels cannot be extracted from the hanging ropes because of the occurrence of harmful microalgae (D). The coefficient c1 = 37 ± 2 days indicates that an average [tau] over the upwelling season of 25 ± 1 or 50 ± 3 days reduce mussel extraction to only 50 or 25\% of the year, respectively.
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