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

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 Pseudonitzschia 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). *Corresponding author: Sonia Sanchez, Instituto del Mar del Peru (IMARPE), Esquina Gamarra y General Valle s/n Chucuito, La Punta, Callao Casilla Postal 22. Callao, Peru, Tel: +5116250800; E-mail: soniasan@imarpe.gob.pe (or) sosarami@hotmail.com Received November 21, 2017; Accepted November 25, 2017; Published November 29, 2017 Citation: Sanchez S, Bernales A, Delgado E, Chang FC, Jacobo N, et al. (2017) Variability and Biogeographical Distribution of Harmful Algal Blooms in Bays of High Productivity off Peruvian Coast (2012-2015). J Environ Anal Toxicol 7: 530. doi: 10.4172/2161-0525.1000530 Copyright: © 2017 Sanchez S, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Citation: Sanchez S, Bernales A, Delgado E, Chang FC, Jacobo N, et al. (2017) Variability and Biogeographical Distribution of Harmful Algal Blooms in Bays of High Productivity off Peruvian Coast (2012-2015). J Environ Anal Toxicol 7: 530. doi: 10.4172/2161-0525.1000530


Introduction
Algal blooms or ´red tides´ are natural monospecific proliferations of certain species of phytoplankton belonging to different taxonomical groups and some photosynthesizer ciliates that cause changes in the color of the sea turning it reddish, brownish, dark brown or even without color; forming irregular spots or patches that can reach some kilometers [1]. Harmful Algal Blooms are increasing worldwide problems observed in peruvian coastal ecosystem, which supports a growing anthropogenic activity that impacts on resources. For the Northern Humboldt Current Ecosystem (Peruvian Sea), red tides records are available since 1980 with information from coastal laboratories of IMARPE, and a monitoring program was established since 2003. Harmless and harmful (potentially toxic) phytoplankton species have been recorded. Among harmless dinoflagellates, Akashiwo sanguinea, Prorocentrum micans, P. gracile, Ceratium fusus v. fusus, C. dens were reported with much frequency. Harmless diatoms such as Pleurosigma sp., Amphiprora sp, Skeletonema costatum, Leptocylindrus danicus, Entomoneis alata v. alata and silicoflagellates such as Dictyocha fibula were reported as well. The first reports of potentially toxic phytoplankton were realized by Pisco-Paracas Coastal Laboratory at IMARPE from 2005-2007, three new species were registered belonging to Prorocentrales, Order: Prorocentrum minimum, P. cf. balticum, and P. lima considered as potentially toxic Cabello et al. [2], concluded that the intense industrial activity of the fishing factories at the inner part of the bay favored the development of a harmful algal bloom caused by Prorocentrum micans exerting a negative synergic effect on the quality of the water column and sediments, which caused the mortality of the scallops. Here, we assess seasonal and interannual variability of toxic phytoplankton in four bays of the Peruvian sea from 2012 to 2015 looking for relationship between biological and physical-chemical components.

Materials and Methods
The sampling was carried out during summer and spring from 2012 to 2015 in four bays of the Peruvian sea (Sechura 04°S, Samanco 09°S, Miraflores 12°S and Paracas 14°S). Water samples were collected with Niskin bottles at surface and bottom depths for phytoplankton, salinity, nutrients, oxygen, chlorophyll and pH. Temperature was measured with surface thermometer, and water column currents with ADCP. Integrated-depth samples were obtained by using a detachable hose in sections [3]. The quantitative analysis was done by Utermöhl methodology [4], giving the results in cell L -1 (Figures 1 and 2).

Results and Discussion
The composition of phytoplankton communities reflects life-forms selections modulated by species-specific features [5]. Therefore, species assemblages registered, tend to share characteristics in response to the ecological history of the body of water in which they are found in the different bays studied. 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 <3.91 and 25.0 cm/s, respectively, with clockwise gyres that influenced harmful algal blooms ( Figure 3).

Statistical analysis
To explore data dispersion and distribution, boxplots were graphed using MINITAB 16. Spearman's correlation coefficients between potentially toxic phytoplankton abundances (diatoms and dinoflagellates) and physical-chemical parameters were obtained with     R program (R studio).
The highest variability in number of potentially toxic species was recorded off Miraflores and Paracas bays during summer 2013, related to sea surface temperatures between 16.4°and 24.1 °C; however, potentially toxic dinoflagellates abundances were favored with fewer species in summer 2014. Miraflores and Samanco bays showed high number of potentially toxic species associated with great abundances (cell. L -1 ) during spring (Figures 4 and 5).
A multivariate analysis of ecological data was done for potentially toxic diatoms and dinoflagellates by performing Canonical Correspondence Analysis (CCA) in order to detect patterns or gradients of these species distribution related with environmental parameters. CCA axis 1 and 2 explained 50% of the variance in the species. Three environmental preferences was found. Species such as Karlodinium sp. (Karl) and Gonyaulax spinifera (G spi) were favoured in low phosphates and silicates waters during summer 2013, while blooms of Group P. delicatissima (P del) and G. P. seriata (P ser) were positively correlated with high oxygen and pH values during springs 2013 and 2014. Finally, Prorocentrum minimum (P min) occured mainly in high nitrates waters during summer 2014 ( Figure 6).