Results from UK and France laboratories released by the government Monday “indicated negative for any poisonous materials” in the ponds in which the fish were killed.
A third result is however yet to be received from the Norwegian Veterinary Institute.
Large quantities of the fish, said to be about 18,000 tonnes, were in October destroyed by the Chinese-owned company, Fujian Farms at a site outside the farm premises in the Shai Osudoku District of the Greater Accra Region.
The cause of death of the tilapia, allegedly imported into the country, was not immediately established as officials of the Ministry of Fisheries and Aquaculture on October 19, 2018 said that they were yet to conduct laboratory tests.
The situation caused panic among the tilapia consuming public at the time, despite assurances by the Ghana Aquaculture Association which said the situation was contained.
Some claimed the tilapia fish were genetically modified while others suspected they might have been killed by poison; something that even heightened the fears of the public especially when it emerged some of the dead fish bound for destruction had found its way onto the market.
“Our fears of poisonous substances have been ruled out from the diagnostic reports received so far,” a statement issued by the Ministry of Fisheries and Aquaculture on November 19 assured.
According to the government, results it received from the Ghana Standards Authority Laboratory and the Ridgeways Laboratory in the UK showed no poisonous substances in the dead fish or the water.
So what cause the deaths?
Government said investigations revealed that the Kpong Dam was spilled the day before the fish kill incident, and that clinical observations of the dead fishes showed “clouded gills with high hyperemia of the gills and excessive mucus exudation”
These signs, it explained, suggest that there was a problem with the environment of the fishes the farm and that “the cause of the kill could either be a foreign matter in the environment or low dissolved oxygen”
It said this was corroborated by the results received from M/S Aquavet Solutions representing ICYTO Pharma, a lab in France.
The laboratory, according to the Ministry, identified the presence of “streptococcus agalactiae” as possible cause of deaths of the fish at the farm.
This virus, it noted, was not new in the industry as it has since 2005 been affecting the industry, adding an “autogenous vaccine” has always been used to address mortalities arising out of the virus.
Based on these reports, the Ministry said it has caused the Fujian Farm and other nearby farms which were closed down after the fish kill, to reopen for business.
It said the results have put the Ministry in a position to declare products from the Fujian Farm and nearby farms healthy for consumption because they “pose no public health risk to the consuming public.
“Considering that the continuous closure of the farms could lead to high production cost and its attendant high prices for the consumer, the farms have therefore been opened”.