By Francine Black, Staff Reporter
Workers from the National Water Commission (NWC) remove dead fish from the Mona Reservoir yesterday. - Ian Allen/Staff Photographer
THE NATIONAL Water Commission (NWC) has removed over one million dead fish from the Mona Reservoir since it was alerted to the fish kill, and continues to sweep the pond daily for more.
On a tour of the facility yesterday, led by President E.G. Hunter, NWC staff advised that the dead fish are bagged and then buried on the commission's property.
The NWC, which launched a probe into the fish kill on January 27, said they were alerted after some 800 small dead fish were seen by representatives from its quality assurance and environment divisions floating on the surface of the reservoir or washed on to the sides.
Since then, the fish continue to die at a similar rate every night.
While this is only a fraction of the millions of perch estimated to be living in the reservoir, the NWC maintains that the deaths were normal, and that water quality tests continue to show that the water is safe.
The commission theorises that there are just too much fish in the water fighting for a limited supply of oxygen.
DISSOLVED OXYGEN
"We have confirmed that the die off is due entirely to the fluctuation in dissolved oxygen, which is a natural phenomenon," said Mr. Hunter.
The NWC said its test results have confirmed this initial theory.
Courtney Lawes, vice-president of the NWC's Eastern Division, and Charles Buchanan, corporate public relations manager, said extensive testing of the fish and water by its laboratory, the University of the West Indies, and the Public Health Laboratory, have confirmed that the kill was not caused by any pesticides or other chemical poisoning, but resulted from oxygen depletion.
Meanwhile, the NWC has announced plans aimed at managing the fish population, including filling it with tilapia to eat the young perch.
Mr. Hunter also said they were considering using nets to catch some of the fish, but noted that the use of nets would have to be controlled to ensure that the balance of the reservoir's eco-system was maintained.
Residents of Mona had become concerned about the public health risks from the fish kill after a terrible smell began emitting from the reservoir on a regular basis since the initial kill.
According to Mr. Hunter, the smell was caused by the NWC's tardiness in collecting and disposing of the bagged dead fish.
ODOUR EPISODES
"There was some odour episodes arising from the collection and disposal of the fish. Perhaps we weren't as proactive as we ought to have been in terms of arresting the situation very quickly," he said.
The rate of dying has decreased and so jogging is to be resumed shortly, he said.
The Mona Reservoir is the largest in the island, holding between 800 to 900 million gallons of water. The reservoir's intake comes from the Yallahs River in St. Thomas and the Hope River in St. Andrew, which wash fish and eggs daily into the reservoir, causing the population to swell.
The NWC also took The Gleaner through the treatment process, which sees numerous purification processes being employed to the water before it reaches the customer.
