In a reason not known so far, at least 137 sea lions were found dead on a beach in Mexico.

Mexican environmental protection officials have said that the deceased lions have not shown any injuries of having stuck in fishing nets or lines, reported Sky News. 

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Marks that are present after they get collide with boats were also not found. 

The above-mentioned causes are the common ones behind the death of sea lions. 

The dead lions were found along an 80 mile (130km) stretch of Comondu coast in Baja California Sur state.

Due to a threat of extinction, California sea lions are granted protection in Mexico.