Survey and Estimates of Commercially Viable Populations of the Sea Cucumber Actinopyga mauritiana (Echinodermata: Holothuroidea), on Tinian Island, Commonwealth of the Northern Mariana Islands

Abstract

A survey was conducted in 1997 to assess commercially viable populations of the surf redfish, Actinopyga mauritiana, and establish a harvest quota for those populations on the island of Tinian. A simple random sampling approach was employed using circular plots as samples. Outer reef flat and reef slope habitats were sampled, producing a total of 333 samples over a 2-month period, with a preharvest population estimate of 71,034. A harvest quota of 17,893 surf redfish was established due to stock depletions on both Rota and Saipan, uncertainty of the density required to ensure successful reproduction of the species, and high degree of uncertainty in the population estimates. It was determined that a stratified sampling approach utilizing either simple proportional or optimal allocation would have resulted in more precise estimates, and these approaches are favored for any future survey work. Population estimates should be revised when more accurate estimates of A. mauritiana habitats become available.