Biomasa, diversidad y abundancia del zooplancton en la zona de San Mateo-Manabí durante los meses de Julio de 2023 a febrero de 2024.

Abstract

Zooplankton play a vital role in the food web; located at the second level, they continue the transfer of energy that begins with primary producers. They are also directly linked to fishing activity and indicate healthy ecosystems. The objective of this research is to examine the relationship between the abundance, composition and diversity of zooplankton with different environmental parameters during a specific period of time. The study was conducted in the coastal/coastal region of San Mateo from July 2023 to February 2024 using the trawl method with 300 μm nets approximately 10 minutes at each station during the weekly day and night hours. Sea surface temperature (SST), pH and total carbonate (carbonate and bicarbonate) analysis were measured. The SST did not have as much influence on the abundance of these organisms, however, it obtained an overall average of 27.51 °C. In addition, it was observed that pH and carbonates presented a significantly negative correlation with zooplankton abundance, with an overall average of 8.37 for pH AND 0.18 in carbonates for both cycles. Zooplankton abundance during the diurnal period was 11.32 org/m³, while 11.29 org/m³ was recorded during the nocturnal period. Statistical tests showed that there were no significant differences between the daytime and nighttime periods. A total of 17 species were recorded in the study, distributed in 3 phyla: Chaetognatha, Annelida and Arthropoda, the latter being the phylum with the highest frequency of occurrence. These findings contribute to a better understanding of the dynamics of aquatic ecosystems and the influence of environmental variables on zooplankton community structure. It is concluded that the increase in temperature is not expected to have an influence on zooplankton abundance, while pH and carbonates show a negative correlation.