Variación espacial y temporal del fitoplancton con énfasis en las floraciones algales frente a la playa de pescadores artesanales de Chorrillos / Lima / Perú

This study examined the spatial and temporal variability of the phytoplankton communities and
their physicochemical variables in three stations at Pescadores Artesanales beach, located in
Chorrillos (Lima, Peru). In situ measurements of temperature and pH were made every month for a
year, while salinity and dissolved oxygen for half a year. Surface water samples were collected to
determine the phytoplankton composition. A total of 120 phytoplanktonic taxa were identified,
belonging to 46 families and 66 genera. Phytoplankton species were dominated by diatoms (59.2%)
and dinoflagellates (35.6%). Phytoplankton abundance was dominated by the Raphidophyceae
(73.72%) followed by dinoflagellates (11.75%), and nanoflagellates (11.53%). Algal blooms were
formed by Thalassionema nitzschioides, Skeletonema costatum, Akashiwo sanguinea, Heterosigma
akashiwo, Prorocentrum gracile, P. balticum, P. minimum, Scrippsiella acuminata, Dictyocha
fibula, Leucocryptos marina and some nanoflagellates (< 20 µm). The highest phytoplankton
abundance was observed in summer and autumn. Significant correlations were found between
phytoplankton communities and physicochemical variables. Abiotic factors such as dissolved
oxygen, temperature, salinity and pH favored the presence of algal blooms. Existence of potentially
toxic / harmful phytoplankton species suggests a higher monitoring frequency of harmful algal
blooms (FAN) at Pescadores Artesanales beach