UPV Digital RepositoryUPV-DRUniversity of the Philippines Visayas
 

UPV Theses and Dissertations

Permanent URI for this communityhttps://hdl.handle.net/20.500.14583/10

Browse

Filters

Settings

AGROVOC Keyword: search.filters.agrovoc.phytoplanktonHas files: Yes

Search Results

Now showing 1 - 5 of 5
  • Thumbnail Image
    Item
    Abundance, composition and distribution of phytoplankton in Mindoro Strait
    Bayona, Riena Rose M. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2008-04)
    Phytoplankton in Mindoro Strait, north of Palawan, were investigated from the samples taken last April-May 2007. Twenty stations were selected from over 40 stations surveyed. Samples were collected by filtering 50L of surface waters through 20 micrometer mesh plankton net using a 10L bucket. Phytoplankton assemblage was grouped into four major taxa. Diatoms dominated the area. It recorded the highest mean density of 314.9indivL-1. It was followed by blue green algae that noted a mean density of 165.69indivL-1. The next most abundant was dinoflagellates that recorded a mean density of 51.59indivL-1 and then the group of silicoflagellates. It recoded 35.69indivL-1 mean density. The top three species were Trichodesmium, Thalasiothrix and Isthmia. Protoperidinium represented the dinoflagellates among the top genera while Eutintinnus recorded the highest silicoflagellate. Higher concentrations were found in the midst of the oceanic region where water currents mainly pass. Overall abundance is lower than other nearby waters. This is maybe due to the effect of water currents.
  • Thumbnail Image
    Item
    Abundance, composition and distribution of phytoplankton in West Central Sulu Sea
    Bria, Jed B. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2008-11)
    A total of 28 stations were sampled for abundance, composition and distribution of phytoplankton in the West Central Sulu Sea. The samples were taken from 15-30 April 2007. Samples were collected by filtering 50L of surface water through a 20 pm mesh plankton net. A total of 96 phytoplankton genera were identified and were grouped into four major taxa. The overall mean density was 444.6 cells/L. Diatoms were the most abundant, with the mean density of 213.5 cells/L. The most abundant diatom genus was Chaetoceros. Blue-green algae showed the second-highest mean density of 127.6 cells/L. Trichodesmium was the most abundant genus among the two blue-green algae identified. Trichodesmium was also the most abundant genus, comprising 28.1% of all phytoplankton identified. Dinoflagellates and silicoflagellates were ranked third and fourth among the four major taxa with 77.5 cells/L and 28 cells/L, respectively. Protoperidinium was the most abundant dinoflagellate, while Amphorella was the most abundant silicoflagellate. They made up 6.2% and 1.2 % of all phytoplankton identified, respectively. The stations located along the coast of Palawan and near the Tubattaha Reef Marine National Park showed the highest phytoplankton concentrations.
  • Thumbnail Image
    Item
    Diel feeding patterns of angelwing clam Pholas (Monothyra) orientales (Gmelin, 1970)
    Alojepan, Marbe Joy L. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 1999-04)
    Filtration rate of Pholas orientalis measured using the indirect suspension deletion method and monitored by direct algal cell counts. Phytoplankton Isochrysis galbana was used as food at an algal cell concentration of 2.5 x 103 cells ml ”'. Biological rhythms have been demonstrated in all animals and plants except bacteria. They control rhythmic patterns in behavior and physiology of a living organism. Biological rhythms, or oscillations, have a “period” that is measured from one arbitrary point or phase of the rhythm to the next occurrence of that phase. They are best demonstrated in a 24 h cycle or circadian cycle. There is a widely varying feeding activity in the 24h cycle of P. orientalis observed at a constant temperature of 27$C and hydrogen ion concentration of 35%o Like any other bivalves, P. orientalis has defined feeding periods equivalent to food uptake at 2400h-0300h. Such observation could be supported by a previous study by Corda stating that optimal feeding was obtained at total darkness. Periods of digestion occur shortly after the periods of feeding. P. orientalis when actively feeding were observed to have extended siphons, larger valve openings, and an inclination of 45. One primary external stimulus that affected filtration rate was the amount of light present. Biorhythms provide temporal information, such as the time of day or season of the year, which facilitates adaptation of the organism to internal or external environments.
  • Thumbnail Image
    Item
    Phytoplankton assemblages in contrasting seasons in the area of Banate Bay, Iloilo, Philippines
    Alvarez, Rose Ann T. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2019-06)
    Banate Bay in Iloilo is one of the major food and occupation contributors in the Panay Island because of its rich biodiversity. This study investigated the phytoplankton assemblage and their diversity with respect to the contrasting seasons namely; December 2012 and June 2013 on the pre-selected nine (9) stations of the Coastal Ecosystem Conservation and Adaptive Management (CECAM) Project. Physicochemical parameters such as salinity, turbidity, DO, and pH did not display seasonality but total suspended solids (TSS) did, with increased values resulting from run-off from the surrounding watershed and rivers. Principal Component Analysis divided the stations during the two months into groups. Station B3 during June 2013 possessed low salinity level, low turbidity level, low pH level and a very high DO level. While the other stations during June 2013 and all the stations during December 2012 possessed higher salinity levels, higher turbidity levels, higher pH levels and lower DO levels. While the PC2 of PCA divided the stations according to the TSS levels and the temperature. All stations during December 2012 showed characteristics of higher TSS levels and lower temperatures while stations during June 2013 were observed to have low TSS levels and higher temperatures. A total of 86 genera falling under six families were identified from the samples, namely: bacillariophyceae (49 genera), dinophyceae (24 genera), cyanophyceae (6 genera), silicoflagellate (4 genera), chlorophyceae (1 genus), euglenophyceae (1 genus) and Miscellaneous (2 genera). In December 2012, a total of 84 genera were identified and 86 genera in June 2013. The top 10 genera with the highest mean densities were Bacteriastrum, Chaetoceros, Eutintinnus, Guinardia, Leptocylindricus, Lioloma, Protoperidinium, Thallasiothrix and Trichodesmium. Pearson’s correlation analysis revealed that water temperature and TSS were the most significant parameters influencing the distribution and seasonal shift in phytoplankton families and genera such as Bacillariophyceae, Others (composed of Euglenophyceae, Chlorophyceae, Myrionecta, and Globigerina), Protoperidinium, and Guinardia. pH and DO had minor influence on phytoplankton distribution. Shannon- Wiener diversity index as a pollution index suggested that the study area was incipiently polluted at stations Bl, B2, and B3 and marginally polluted at Stations B4, B5, GN1, GN2, GS1, and GS2. Despite potential effects of various human activities, the water quality and phytoplankton assemblage of this area has not reached an alarming situation. The current study provides valuable baseline data.
  • Thumbnail Image
    Item
    Semiparametric and parametric modelling of vibro species abundance production system
    Dequito, Angel Queenee D. (College of Fisheries and Ocean Sciences, University of the Philippines Visayas, 2017-09)
    Vibrio species that cause white spot disease and vibriosis are known to be influenced by environmental factors. In this study, the changes in the abundance of presumptive Vibrio species from a biofloc shrimp production system with respect to physicochemical and biological parameters were evaluated. Parametric and nonparametric modelling techniques were used to identify and predict changes in Vibrio abundance in relation to alkalinity, ammonia, dissolved oxygen, nitrite, pH, salinity, temperature, transparency, and phytoplankton and zooplankton densities. Abundance was found to be highly correlated with alkalinity, pH, and phytoplankton density as revealed by both parametric and semiparametric models. Generalized additive model (GAM, a semiparametric model) is the best model based on Aikaike’s Information Criterion (AIC) values in which 41.2% of the variability in the dependent variable can be explained by the predictors compared to ordinary linear regression and negative binomial models (parametric models) with 16.04% and 14.5% respectively. Prediction on the abundance can help prevent bacterial diseases in shrimp as this will provide an insight to the farmer about when to and which water parameters or predictors can be controlled. Thus, it is important to consider the use of semiparametric modelling approach as a tool for fish health management and to prevent losses in aquaculture.