Echinometra Viridis Essay

POPULATION ESTIMATION OF TROPICAL URCHIN, Echinometra viridis, IN BARANGAY KANYUKO, DUMANJUG, CEBU
Genesis Caparida1, Abigail Lastimosa1, and Marjorie Villareal1
1BS Biology Students, Department of Science and Mathematics, University of San Jose- Recoletos

Introduction The mark-recapture method is a powerful method for conservation managers, and can be used in any situation where animals can be marked and detected later by capture or sighting (Lettink and Armstrong 2003). It is also a powerful method for estimating abundance as long as underlying assumptions are met. Echinometra viridis , a small (0.5-4.1 cm diameter) long spined, tropical sea urchin (Griffin et al. 2003), is considered to be one of those sea urchins reported to regulate

viridis in the neritic zone along the shores in Barangay Kanyuko, Dumanjug, Cebu while considering several assumptions (i.e. a) there is no birth, death or immigration during the study b) all animals have the same probability of being caught c) marks are not lost). The simplest case involves two capture sessions. In the first capture session, group of E. viridis was caught, marked and released. The population is then re-sampled on one subsequent occasion. The method was developed independently by Peterson in the 1890s to estimate the size of fish populations and by Lincoln in the 1920s to estimate wildlife populations. It is therefore called Lincoln-Petersen estimate (Sebar 1982).
Objectives
This study aims to administer the Lincoln-Petersen method of population estimation in the field. Several assumptions used in the mark-and-recapture technique must be determined and enumerated. Consequently, a comparisons and contrasting should be made between the results of the Lincoln-Petersen method to the Chapman estimator. Calculations for the estimated population size of the subject of E. viridis must be made. And lastly, ecological implications must be identified after the analysis and interpretations of the value gathered.
Significance of the