Chemical Contents of Disposed Light Sticks Affect the Physiology of Rocky Crab Pachygrapsus transversus and Gray Shrimps Litopennaeus vanammei.

Abstract

Light-sticks shine resulting from a chemiluminescent reaction between two components kept separate by a glass ampoule. Light-stick baits are discarded in the ocean after being used in longline fishing. The traditional Brazilian community of Costa dos Coqueiros, Brazil, uses the discarded light-sticks chemical contents found on beaches as medicine for rheumatism and mycoses. This study assessed the effects that light-sticks (chemical contents) have on Pachygrapsus transversus and Litopennaeus vanammei. Assays of metabolic changes involved rates of ammonia excretion and oxygen consumption. The EC50-60min to juveniles and adults P. transversus were 0.0004% and 0.0046%, respectively; and L. vanammei revealed a susceptible species: EC50-60min of 0.0006% for oxygen uptake and 0.0072% for ammonia excretion, and also was observed a hormesis effect in the ammonia excretion. Light-stick contents could promote significant metabolic changes in rocky crabs and gray shrimp. Educational actions are needed that make the population aware of and avoid the dangerous misuse of the light-sticks.