Research Article Phytoplankton Community Composition of Carigara Bay, Leyte and its Freshwater Tributaries Hernando Alice Geraldine S1,2,*, Susana F. Baldia1,3, Paciente A. Cordero Jr.1,4 1The Graduate School, University of Santo Tomas, Sampaloc, Manila, PHILIPPINES. 2College of Arts and Sciences, Mariano Marcos State University, City of Batac, Ilocos Norte, PHILIPPINES. 3Research Center for the Natural and Applied Sciences, University of Santo Tomas, Sampaloc, Manila, PHILIPPINES. 4Eastern Visayas State University, Burauen Campus, Burauen, Leyte, PHILIPPINES. Submission Date: 13-05-2020; Revision Date: 22-06-2020; Accepted Date: 27-06-2020 ABSTRACT Correspondence: Carigara Bay is one of the acclaimed richer fishing waters in the entire Philippines because of Prof. Alice Geraldine S. Hernando, its multi-gear fishery system. Filipinos living around the bay considered its marine life as one of Department of Biological their livelihood. However, the biodiversity of phytoplankton are still unexplored evident by the Sciences, College of Arts dearth of published data in scientific journals. Thus, this study was undertaken. Sampling was and Sciences, Mariano conducted on the five coastal towns surrounding the bay and its freshwater tributaries are Lindog Marcos State University, and Bislig River found in Brgy. Uyawan and Bislig respectively situated in Carigara, Himanglos and City of Batac, Ilocos Norte, PHILIPPINES. Canomantag River in Brgy. Hilaba and Canomantag in Barugo, stream located in Brgy, Libertad, Capoocan, Caraycaray River and Lipasan Falls in Brgy. Caraycaray and Pinarigusan in San Miguel Email: alicegeraldin_her- and Tula-an and Busay Falls in Brgy. Tula-an and Busay in Babatngon. Water samples were [email protected] collected using a 2.5-3L Plexi glass sampler, transferred in three 1L cap bottle and brought in the laboratory for phytoplankton identification. Physico-chemical parameters were also gathered in all sampling sites to correlate with the phytoplankton density. Data were subjected to statistical analyses such as two way ANOVA. Results showed that there are three phyla quantified such as Bacillariophyta, Chlorophyta and Cyanophyta which are 44, 37 and 19% of the total phytoplankton. These were correlated with the physico-chemical parameters where in there was a significant positive correlation between water pH (r = 0.499; p = 0 .001), conductivity (r=0.519; p=0.001) and amount of phosphates (r = 0.446; p = 0.003) to the total cell density of all the three groups of phytoplankton identified. Key words: Bacillariophyta, Freshwater resources, Microalgae, Physico-chemical parameters, positive correlation. INTRODUCTION total species and contribute half of the total percentage of oxygen in the atmosphere. In addition, microalgae Algae have approximately about 50,000 species and are considered to be major indicators of oceanic health more, but only half of the total species are known and water quality.[2] This is shown by the green water taxonomically. Microalgae or commonly known as technique wherein phytoplankton are introduced in the phytoplankton are the base or bottom of the aquatic food ponds of reared aquatic animals for survival, growth chain that produce food and natural nutrients for many and development.[3] This technique is necessary for the vertebrates and invertebrates living in the freshwater improvement of water quality such as pH, turbidity and and marine niches.[1] These producers cover 75% of the dissolved oxygen, immunity and other health conditions, larval metamorphosis and regulation of bacterial species SCAN QR CODE TO VIEW ONLINE and other pathogenic organisms.[4] More importantly, www.ajbls.org only 15 micro algal species are involved in the current commercial production such as feed, food and other DOI : important products in various fields and industries yet 10.5530/ajbls.2020.9.29 they are thought of as the most poorly studied group of aquatic organisms. Carigara Bay, one of the richer fishing 190 Asian Journal of Biological and Life Sciences, Vol 9, Issue 2, May-Aug, 2020 Hernando, et al.: Phytoplankton Community Composition of Carigara Bay, Leyte (Philippines) And Its Freshwater Tributaries waters in the Philippines, is located in the Province of Collection of Water Samples Leyte, Region 8 or the Eastern Visayas. Its freshwater The water samples were collected during July 2-8, tributaries such as streams and rivers emptying into the 2018 which was considered as the 1st sampling and on Pacific Ocean, keeps the marine life moist in condition November 23-26, 2018, the 2nd sampling. Collection over many months.[5] The bay itself and its freshwater of water samples from the bay was done by towing 30 resources abound with a diversity of organisms, but meters away from the shoreline. The water samples from poorly studied as shown by dearth of reports. In fact, the bay for phytoplankton qualitative and quantitative the study on the assessment of water quality and initial analyses were gathered 30 meters away from the shoreline identification of zooplankton and phytoplankton is with a depth of 1-1.5 meters only. For the freshwater solely the existing biological report about Carigara bay.[6] tributaries of the bay, the water samples were collected Thus, this study on the identification and assessment of in integrated manner, thus, from surface, middle and phytoplankton in Carigara Bay and freshwater resources approximately 0.5 meter away from the bottom. Most in its vicinity easily serves as baseline information for have depths ranging from 0.75- 2 meters. Depths were future studies. The objectives of this study included the measured using the plexi glass sampler attached to a rope following: identify and quantify phytoplankton found in with measurement in meters and/or the sec chi disk. The Carigara bay and its freshwater tributaries and correlate 3L water samples from the river/falls were apportioned the phytoplankton density to the physico-chemical for the different analyses from which 1L was taken for parameters at the different sampling stations established. phytoplankton analysis and fixed with Lugol’s solution to preserve the cell wall of phytoplankton; 1L was kept METHODOLOGY cold during the transport at University of Santo Tomas, Manila and immediately stored in freezer or placed in Sampling Sites a refrigerated condition upon arrival in the laboratory Carigara bay located in Leyte, a sister island of Samar for ex situ nutrient determination of the water samples such as nitrate and phosphates. The other 1L was used is one of the biggest land masses in the Philippines. as a live sample for plankton verification. Furthermore, Carigara bay is connected by freshwater tributaries in prior to collection, physical parameters such as surface the five (5) coastal towns surrounding the marine life. water temperature, column depth, light penetration or Fourteen (14) stations were established at the upper transparency and chemical parameters such as water coastal towns adjoining the Carigara Bay (Figure pH, conductivity and dissolved oxygen were recorded 1). Station 1 was the Carigara Bay at Brgy. Libertad in situ. All of the parameters were measured using the (Capoocan) (11°39’N 124°53’E); Station 2 was a stream Explorer GLX (PAASCO) water quality instrument at Brgy. Libertad (Capoocan) (11°37’N 124°52’E); except for the light penetration or transparency which Station 3 Carigara Bay at Brgy. Visoria (Carigara) was determined using a Secchi disc. In addition, analyses (11°30’N 124°68’E); Station 4 was the Lindog River at of nitrogen and phosphorus were measured using the Brgy. Uyawan (Carigara) (11°27’N 124°66’E); Station 5 spectrophotometer (Hach DR/2010) at the Roque was the Bislig River at Brgy Bislig (Carigara) (11°29’N Laboratory, Old Graduate School, University of Santo 124°67’E); Station 6 was the Carigara Bay at Brgy. Tomas. Duka (Barugo) (11°36’N 124°78’E); Station 7 was the Himanglos River at Brgy. Hilaba (Barugo) (11°31’N Qualitative and Quantitative Analyses of 124°73’E); Station 8 was the Canomantag River at Phytoplankton Brgy. Canomantag (Barugo) (11°30’N 124°71’E); For quantification, an appropriate amount of Station 9 was the Carigara Bay at Brgy. Mawod-pawod phytoplankton sample was loaded in a Neubauer (San Miguel) (11°19’N 124°51’E); Station 10 was the Counting Chamber for density determination as viewed Caraycaray River at Brgy. Caraycaray (San Miguel) using the Olympus CH20 compound light microscope. (11°20’N 124°52’E); Station 11 was the Lipasan Falls [7,8,9] For qualitative determination of phytoplankton, at Brgy. Pinarigusan (San Miguel) (11°21’N 124°53’E); several references on algal taxonomy and biodiversity Station 12 was the Carigara Bay at Brgy. Kalangawan were used such as the following: Taxonomy and Ecology Guti (Babatngon) (11°23’N 124°51’E); Station 13 was of Algae in Fishponds and Fishpens of Laguna and the Tula-an Falls at Brgy. Tula-an (Babatngon) (11°24’N some Physiological Studies of Navicula accomoda 124°52’E) and Station 14 was the Busay Falls at Brgy. Hust; [10] Taxonomy of the Freshwater Algae of Laguna Busay (Babatngon) (11°25’N 124°53’E). de Bay and Vicinity;[11] Illustrations of the Freshwater Asian Journal of Biological and Life Sciences, Vol 9, Issue 2, May-Aug, 2020 191 Hernando, et al.: Phytoplankton Community Composition of Carigara Bay, Leyte (Philippines) And Its Freshwater Tributaries Plankton of Japan;[12] Algae of the Western Great Lakes the sampling stations of the said bay. The Chlorophyta Area;[13] and How to Know the Freshwater Algae.[14] groups in Stations 1 and 6 dominated and gave the highest cell density compared to other phytoplankton Statistical Analyses in July 2018. Also, the Cyanophyta groups in Stations 9 Statistical analysis such as the Two-way ANOVA with and 12 had the highest cell density compared to other replication was used to compare the physico-chemical phytoplankton in November 2018.