The Swakop River’s rare flow into the Atlantic Ocean – a phenomenon last observed in 2022 – is said to have triggered ecological disruptions along the Swakopmund coast in Namibia.

Heavy rainfall caused the Swakop River to surge into the ocean on April 1.

A video shared with Erongo and posted on its Facebook page shows hundreds – if not thousands – of dead sea creatures, including octopuses, little sharks and other sea life – washed ashore.

“The mass die-off is believed to be linked to either a sulphur eruption currently, or the sudden influx of fresh water, sediment and debris carried into the Atlantic by the Swakop River breakthrough on April 1,” Erongo said in its Facebook post.

“The mixture of fresh water and silt may have depleted oxygen levels in the shallow marine environment, suffocating the creatures or driving them into distress. While tragic, the incident is believed to be a natural ecological response following the rare flood,” it added.

According to The Namibian, the ‘Swakop River reaching the Atlantic Ocean is a rare occurrence that significantly impacts the local marine environment’.

“The Swakop River is an ephemeral watercourse, meaning it flows only after substantial inland rainfall. Its path to the ocean is infrequent. Prior to this event, the river last reached the Atlantic in 2022.

“When the river does flow into the sea, it brings a surge of freshwater, sediments and organic materials. This influx can lead to abrupt changes in water composition, including reduced salinity and oxygen levels, which can distress marine organisms.

“Marine species such as octopuses, lobsters and various fish may become disoriented or suffocate, leading them to wash ashore.”

Watch: The river meets the sea: