Thousands of dead squid have washed up on the Chilean shores of Santa Maria Island over the past week. The reason for a mass die-out of these large cephalopods is so far a mystery.

The mass death has prompted health concerns locally as around 10,000 decomposing squid bodies have invaded a beach on the small island, causing something of a stench, according to Latin Correspondent.

Technicians from the Chilean National Service for Fisheries and Aquaculture (Sernapesca) have collected samples of the dead squid and water for analysis in specialized centers.

Experts say the phenomenon may have been caused by higher than usual seawater temperatures, but have not ruled out pollution either.

The arrival of dead fish and mollusks on Santa Maria’s beaches at this time of year is not unusual, but this is the first time it has reached biblical proportions.

Experts and local police are working to evaluate the scale of the situation and determine whether it could cause a sanitary emergency.

Heavy machinery was brought in by the Chilean government to remove the dead squid on Wednesday, five days after they began to appear.

The delay has been blamed on the country’s poor emergency response structure.

“God help us that the children do not get sick from the smell,” said one resident in an interview with Reuters.

Deputy Police Chief Mario Grandon said that the squid have been rotting for nearly a week.

“Experts are coming here to determine whether the incident could cause sanitary emergency, which is probable, given the quantity of squid that have washed up here,” he said.

Rodrigo Valencia of the National Fishing and Agriculture Service says preliminary evidence suggests the squid died and washed up on shore due to a phenomenon called “upwelling.” This refers to a situation when dense, cooler and usually nutrient-rich water moves towards the ocean surface, replacing the warmer, usually nutrient-depleted surface water.

“It was caused by an upwelling, due to a drop in oxygen levels, which led to the death of these creatures,” Valencia said.