Thesis (BS Environmental Science) – Mariano Marcos State University-College of Agriculture, Food and Sustainable Development, Batac City

Bibliography:leaves 46-47.

ABSTRACT LACRO, MARK CURT WENZLEY S. and PANTE, JUDY ANNE A. 2021. Zooplankton Assessment in the Mangrove Area of Nagabungan, Pasuquin, Ilocos Norte. Undergraduate Thesis. Department of Environmental Science. College of Agriculture, Food and Sustainable Development. Mariano Marcos State University, City of Batac, Ilocos Norte. 67 pp. Adviser: Prof. Estrelita O. Domingo The study on the zooplankton assessment in the mangrove area of Nagabungan, Pasuquin, Ilocos Norte was conducted from February to March 2021. Specifically, the study aimed to determine the different species, population density and distribution of zooplankton in the mangrove area; determine the physico- chemical characteristics of the water that influence the zooplankton diversity of the mangrove area and relate the physico-chemical characteristics of the water and the zooplankton diversity in the mangrove area. A total of 13 species of zooplankton were found and were broken down as follows: nine orders; ten families and 13 genera and three unidentified species. It was observed that there was a low diversity index of zooplankton (2.25). Furthermore, it is more diverse during full moon phase in both natural stand and planted stand. In terms of population density, zooplankton was highest during full moon in both natural and planted stand. In addition, the mean of evenness obtained in the different sampling periods was 0.72. This indicates that there is uneven distribution of individuals per species 1 and 1.0 indicates an even distribution of individuals. The similarity index is 82% for both the natural and planted stand during the new moon phase, while in the full moon phase it was 100%. Results revealed that during full moon phase whether in natural stand and planted stand, the same species of zooplankton were observed. In contrast, some species of zooplankton were present and some were not observed during new moon, hence a lower similarity index. The physico-chemical characteristics of the mangrove area that were subjected for assessment are temperature, depth, salinity, pH, dissolved oxygen. During full moon phase in the natural stand, the highest temperature was 28.58'C and the coolest is 24.31'C. For the depth, the deepest average was 85 cm during full moon phase in the planted stand. For the salinity, the highest salinity levels were 28.29 parts per thousand (ppt) during new moon phase in the planted stand. The highest pH levels of the water in the mangrove area was 8.34 during new moon phase. In terms of dissolved oxygen, the highest was 5.90 mg/l during new moon phase. Dissolved oxygen is an important parameter in assessing water quality because of its influence on the organisms living within a body of water. Based from DAO 2016-08, the standard for dissolved oxygen is 5.0 mg/l. The higher the dissolved oxygen, the better for the organisms to grow. For the correlation analyses, almost all the correlated water parameters showed a negative relationship with diversity index, population density, evenness and similarity index of the zooplankton. On the other hand, temperature is positively correlated with diversity index, population density, evenness and similarity index.