MICROORGANISM INFECTION OF OLIVE RIDLEY EGGS

Abstract

Nest success among olive ridley turtles nesting in arribadas in Costa Rica is extremely low, ranging from 4-8%. OneofTEe presumed causes of egg loss is fungal and bacterial infection in the beach. We undertook an extensive study of the role of microorganism infection in natural and artificial nests of olive ridleys to determine if bacteria and fungi are primary or secondary agents in embryo death. We found no correlation between level of bacteria or specific fungi in sand and hatching success in Playa Nancite, Santa Rosa National Park, Costa Rica. Experimental infection of eggs in controlled environment in the laboratory showed no difference in hatching rates between infected eggs and controls. The rates varied from 0 to 100% success, with an average of 52.5%. Our results show that when eggs are well hydrated and in optimum temperatures, they can hatch despite the presence of bacteria and fungi. Therefore these should be considered opportunistic agents in egg death caused by other environmental causes.