Relative abundance and percent bottom cover of benthic lifeforms in the marine protected area of barangay poblacion, Kauswagan Lanao del Norte, Philippines

This study was conducted to establish baseline informations on the relative abundance and the percent bottom cover of existing lifeforms of scleractinian corals in the Marine Protected Area of sitio Kauswagan, Brgy. Poblacion, Lanao del Norte., Philippines. The coral reef was assessed using digital photo-transect technique. Acropora lifeforms include branching with relative abundance (RA) of 20%, submassive 10% and digitate 70%. Montipora digitata (Acroporidae)was the most abundant digitate coral in the MPA. Non-Acropora lifeforms include branching with abundance of 38.7%, submassive 24.3%, massive 23.7%, encrusting 6.13%, foliose 0.8%, Millepora 0.8%, mushroom 5.33% and Heliopora 0.27%.The RA of branching lifeforms are 20% and 38.7% in Acropora and Non-Acropora categories respectively while RA of non-branching massive and submassive lifeforms are higher and account for 80% and 41.33% in Acropora and non-Acropora categories respectively. Massive and submassive lifeforms are slow growing, however they withstand strong wave action during storms. The low RA of algae associated with dead corals of 4.79% maybe due to the grazing activities of herbivorous fishes in the reef. Sponges, the most abundant fauna can possibly limit growth and cause death to corals due to poor nutrient and oxygen supply secondary to obstructed water flow and limited sunlight to the coral colony. The high abundance of dead coral and rubble indicated that the reef was exposed to man-made damaging threats as well as to the effects of natural calamities. Non-Acropora lifeforms constitute the highest percentage bottom cover of 32.7%. This is followed by dead corals 22.11% and abiotic lifeforms 13.51%. Acropora has a significantly low bottom cover of 17.21%.