The association of test diameter and gonad weight with some toxic trace metals level in black sea urchin (Stomopneustes variolaris)

Abstract

Background: Quantification of toxic trace metals in biota is very important to monitor both ecosystem health and public health. Stomopneustes variolaris is a widespread species of sea urchin in the world that have edible gonads that are in high demand. This study attempted to examine the levels of accumulated toxic trace metals and their relationship between the test diameter and the gonad weight of the black sea urchin (S. variolaris) in Sri Lanka. Results: As S. variolaris is highly abundant in southwest coast of Sri Lanka, three sampling sites were selected in this region (Mount-Lavinia, Beruwala and Tangalle). The concentration of toxic trace metals (Hg, Cd, Pb and As) in the gonads of S. variolaris was determined in randomly selected subset from the above samples. The levels of above metals in gonads did not exceed the permitted standard levels of the EU and Sri Lanka. The mean size and weight of S. variolaris collected from Mount-Lavinia was 5.55±1.04cm and 101.40±57.76g, respectively; for Beruwala it was 6.54±0.86cm and 147.90±50.40g, respectively, and for Tangalle it was 6.41±1.05cm and 150.50±59.45g respectively. There was a significant relationship between all the analysed trace metals and the test diameter and gonad weight of S. variolaris in Sri Lanka. Conclusions: This study revealed that the trace metal levels in gonads of S. variolaris did not exceed the harmful level for human consumption.