Undergraduate Special Problem
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Item Influence of tidal levels on meiofaunal communities in a rocky shore area in Taklong Island National Marine Reserve, GuimarasBarbasa, Maria Carla A. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2013-04)Rocky shores present an exuberant richness of life, which can be attributed to the hard substrate provided by rocks, necessary for the attachment of sessile organisms. There are many factors affecting community structure in rocky shores, including tidal levels. Tidal levels affect communities by periodically exposing them to air, causing drying up and dessication. Among those affected are meiofauna. Meiofauna in rocky shores are the least studied of all habitats, thus this study serves as baseline information regarding meiofauna in rocky shores, particularly in TINMAR, and how tidal levels affect them. Sorting and identification of meiofauna from 18 samples (5 TST, 5 TLT, 4 TMT, 4 THT) yielded 17 identified taxa, with Harpacticoids being numerically dominant followed by Tanaids (Copepods) and Polychaetes. Mean meiofaunal abundance was found to higher in lower tides (low and sub-tide), but differences were not statistically significant. A similar lack of significant differences between transects was shown for abundances of all and common taxa in edge or mid-section quadrats, although abundances appeared to be higher in low and sub-tidal transects. Cluster analyses based on similarities in abundance of taxa in the transect quadrats showed which asemblages are characteristic of mid- and high tide levels (Insect larvae and Sipunculids). Nematodes, which are typically dominant in soft-bottom substrates, were also most abundant in the upper intertidal in the present study. Other taxa like Tanaids, on the other hand, were more abundant in the low intertidal and subtidal transects. Harpacticoids were observed to be dominant in higher tides.Item Acute toxicity of polysolve oil dispersant to Nile tilapia (Oreochromis niloticus Linn.) fryAtas, Bryan B. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2011-03)Forty eight hour (48h) static bioassays were conducted to determine the toxicity of Polysolve oil dispersant to Nile tilapia (Oreochromis niloticus) fry. Median lethal concentrations (LC50) were 1.03, 0.79, 0.70, 0.45, and 0.39% for 24, 30, 42, and 48h, respectively. Polysolve is highly toxic to Nile tilapia fry at low concentrations. Results showed increasing toxicity over increasing length of exposure. It is therefore recommended that Polysolve must not be used in oil spill response. Sublethal effects of the dispersant on the fry include decreased activity and impaired responsesItem Spatial variations of Benthic meiofauna communities from Palompon Bay, Northern LeyteBalasa, Melvy June (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2013-04)Meiofauna play a significant role in maintaining ecological balance in marine ecosystems especially in the dynamics of the seagrass meadows. The meiofauna links the upper trophic level with detritus-feeding organisms. Only few studies have been conducted in the Philippines, while no studies have been. This study was conducted in Palompon, northern Leyte in November 2011, to determine the spatial distribution of meiobenthic fauna in the area and to compare community structure in terms of species composition, species density, and species diversity among five stations included in the survey. Twenty taxa were identified with nematodes being numerically dominant, followed by harpacticoid copepods. It also showed the highest mean abundance for the entire habitat type. The overall mean density was 194585.1528 ind. m2, with the highest population at station 4. And the lowest population was recorded at station 2. Soft bottom habitat showed the highest recorded mean density among the 5 stations, Harpacticoids mostly dominated sandy substrate while nematodes were widely distributed.Item Growth and nutritional content of red seaweed Gracilaria bailinae (Zhang et. al., 1995) grown under different fertilization schemeAlmojuela, Kristine Marie T. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2012-04)The accelerated development of fish aquaculture has caused many environmental problems. The most evident effects resulting from this activity is the increase in organic material, the reduction in dissolved oxygen and the excessive rise in inorganic nutrients such as nitrogen, phosphorous and carbon dioxide. The integration of seaweeds to fed cultured species has long been recognized as promising approach to reduce the excess nutrients released by aquaculture activity. The nitrogen and phosphate uptake kinetics, growth and nutritional content of the seaweed Gracilaria bailinae were studied in a series of outdoor tanks, fertilized with commercial fertilizer (NH4CI, NaNO3, and Na2HPO4) and shrimp culture waste water. The nutritional content of G. bailinae before and after fertilization was also determined through proximate analysis. Results showed a significant removal of dissolved nutrients by G. bailinae, although definite uptake rate could not be determined since the data were erratic and Michaelis-Menten model could not be applied. Seaweeds fertilized with shrimp waste water showed best specific growth rate (1.37±0.2 % d-1) over other fertilization scheme. This suggests that shrimp pond effluents could promote good growth on G. bailinae. Local G. bailinae had high protein content per se (14%) but became more enhanced when fertilized with commercial or shrimp waste water (23-32%). In contrast, its carbohydrate content dropped when heavily fertilized from 39% to 19%.