சுற்றுச்சூழல் & பகுப்பாய்வு நச்சுயியல்

Variability and Biogeographical Distribution of Harmful Algal Blooms in Bays of High Productivity off Peruvian Coast (2012-2015)

Abstract

Sonia Sanchez, Avy Bernales, Elcira Delgado, Flor del Carmen Chang, Nelly Jacobo and Jorge Quispe

Harmful Algal Blooms are increasing worldwide problems observed in inshore ecosystems, which support a growing anthropogenic activity that impacts on resources. Results of seasonal and interannual variability of toxic phytoplankton in four bays of the Peruvian sea (Sechura 04°S, Samanco 09°S, Miraflores 12°S and Paracas 14°S), are shown during spring and summer from 2012 to 2015. Toxic species such as Pseudo- nitzschia Grupo delicatissima, Grupo P. seriata, Alexandrium peruvianum, Dinophysis caudata, D. acuminata, Gonyaulax spinifera, Azadinium sp, Karlodinium sp., Karenia sp., Protoceratium reticulatum and Prorocentrum minimum were registered, associated with the presence of toxic events, more frequently of okadaic acid (lipophilic toxin - DSP) in Sechura and Samanco for 2012, 2013 and 2014 and saxitoxin (Paralytic Toxin - PSP) in Paracas 2012. Sea surface temperature for spring fluctuated between 16.3° to 19.9°C (Sechura-Paracas), and for the summer between 19.3° to 24.1°C (Paracas - Sechura). Physical dynamics were related with seasonal variations, associated to local effects, with slow surface marine currents during austral summer and intense currents during spring, with average values of <13.91 and 25.0 cm/s, respectively, associated with clockwise gyres that influenced the harmful algal blooms. Spearman correlations (p<0.05) between the biological and physicalchemical component were found mainly with temperature (r=0.665), silicates (r=0.45), phosphates (r=0.48) and nitrates (r=0.50).