DURBAN, South Africa, Dec. 30 (UPI) -- South African industrialist Carl Webb has blamed illegal chemical dumping in Umbilo Canal for the large numbers of dead fish turning up in Durban Harbor.

Since last week, dead fish have lined the walls of the canal, which Webb administers in his role as KwaZulu-Natal regional manager of Natro Freight. He has demanded an investigation, The (Durban) Independent reported Sunday.

Mike Blohan, who has been monitoring pollution levels around Durban for many years, said chemical-related fish kills are common in December as companies start the new year by cleaning out their chemical tanks, The Independent said.

The city is investigating any illegal dumping, City Manager Michael Sutcliffe said, vowing to punish any offenders.

Meanwhile, harborside business owners complained the dead fish were squeezing their profits.