Microalgae dynamics and its relation with Las Peñitas Coast, Poneloya, Nicaragua

Abstract

This is a descriptive investigation that has studied the dynamics of microalgae (Cyanophytas, Chlorophytas, Bacillariophyceae and Dinoflagellata) and their relationship with the physical-chemical parameters of the Peñitas, Poneloya coasts in the period of June-October 2017. It was taken into account samples of 3 different points between the area included in the coordinates 12 ° 20´10.63¨N 87 ° 01´59.58¨O and 12 ° 21´59.68¨N 87 ° 04´13.27¨O. These samples were carried out once a month to analyze water samples and physical-chemical parameters (pH, salinity, temperature, turbidity and oxygen). Cell counts were done with the help of the Neubauer chamber and the identification of microalgae with the help of the Sedgewick-Rafter chamber. Microalgae of the four main groups were found, having more representation of the Bacillariophyceae class with 16 species, followed by Cyanophytas with 7 species, Chlorophytas with 6 species and Dinoflagellata with 5 species. The salinity parameter oscillated between 30 ppm as the minimum value presented in point 1 and 34 ppm as the maximum value presented in point 3, the temperature fluctuated between 27 ° C and 29.7 ° C, having the minimum value in the month of August in the second point and the maximum in the month of June in the third point, the turbidity maintained a stable value of 100 cm in its 3 points throughout the investigation period. The dissolved oxygen varied between 7.3 mg / l and 8.3 mg / l, having its minimum value in the month of June at the first point and the maximum in September at its first point. The pH ranged from 8.6 its minimum, found in the month of June in the second point and its maximum of 10.4 in the month of July in the second point. The Diversity of Shannon and Dominance of Simpson statistical indexes were applied to all the species found, to inquire if the area has abundant biodiversity or there was dominance of a specific species, and according to the results obtained it can be ensured that the area has a diversity and abundance of homogeneous microalgae species.