Videographic methods in assessing benthic community patterns of reefs in Talin Bay, Calatagan, Batangas: Minimum frame subsamples to determine lifeform diversity and cover

Date

10-2001

Degree

Bachelor of Science in Biology

College

College of Arts and Sciences (CAS)

Adviser/Committee Chair

Vincent V. Hilomen

Abstract

MALAYANG, MIHARU JAY RIO. University of the Philippines Los Banos. October 2001. Videographic methods in assessing benthic community patterns of reefs in Talin Bay, Calatagan, Batangas: minimum frame subsamples to determine lifeform diversity and cover. Adviser: Prof. Vincent V. Hilomen Eleven video transects were recorded at three study sites in Talin Bay, Calatagan, Batangas to determine the minimum number of frames required to provide a reliable assessment of lifeform diversity and abundance of sessile benthic coral communities. Lifeform richness and percentage cover data were obtained by identifying lifeforms under five fixed points on frames automatically extracted from video footage at regular 5-second intervals. Analysis was done to determine decreases in efficiency with increases in subsampling effort (i.e., number of frames analyzed). Results indicate that 35 to 40 frames were sufficient to resolve an average of 88.9% t 10.0 of the lifeforms present on the 50-m transects. Minimum number of frames for lifeform richness did not vary significantly between sites. About 40 frames per 50-m transect appear to give at least 70% of the total estimated percent cover of the more abundant lifeforms (in this study, turf algae, algal assemblages, and encrusting and massive coral) and benthic categories. More frames (up to 50 or more independent frames per 50-m transect) will be required to get similar estimates of percent cover of the rarer lifeforms (in this study, all forms of Acropora and other biota). Individual site characteristics such as dominance of any particular lifeform or substratum type were also seen to influence the minimum number of frames required for reliable estimates of percent cover more than estimates of lifeform richness. The most exposed site, Talin Point, had the highest live hard coral cover (44.56%) while the most sheltered site, Bahura Reef, had the lowest live hard coral cover (29.02%). This may have been due partly to more wave action at the exposed site helping keep corals free of smothering sediments. Information generated by this study has large implications on large-scale reef surveys using videographic methods.

Language

English

Location

UPLB Main Library Special Collections Section (USCS)

Call Number

Thesis

Document Type

Thesis

This document is currently not available here.

Share

COinS