Dead fish washing up at umdloti

WHEN dead fish began washing up on umdloti beach, on the Kwazulunatal North Coast, residents and fishermen feared the worst.

And while blame was at first laid at the door of the United Phosphorus Limited (UPL) chemical factory which was burnt down during the July looting, a report by the Marine & Estuarine Research (MER) ecological consultancy has provided a simpler explanation.

According to the MER – which specialises in providing expert monitoring, assessments and advice in coastal aquatic habitats – the mass fish kill was the result of “osmotic shock” when the nearby estuary was breached.

According to the report, written by Professor Anthony Forbes and Nicolette Forbes, on September 11 MER received multiple calls about dead fish washing up at umdloti.

The MER team identified that the species came from a river and estuary, not a marine habitat.

An inspection was started in the north as later reports and observations indicated that there was a concentration of fish on the northern and umdloti beaches and these were carried southward by sea conditions.

The report found that the mouth of the estuary was breached on the night of September 10 or early the next morning.

When the estuary was breached, the tilapia were washed out to sea.

While the fish species can survive in saline water under certain conditions, the report found the rapid surge in salinity coupled with the sudden temperature change caused significant osmotic shock.