He has further directed farmers to limit stocking densities to the carrying capacity appropriate for the respective strata of the lake or lower Volta system to be able to cope with periodic low oxygen tension or deploy air blowers and aerators to improve dissolved oxygen.

In the medium term, government agencies and would work together to ensure that from March 2019, only approved and certified hatcheries would supply fingerlings and broodstocks to farmers.

Speaking at a meeting with fish farmers on Wednesday in Accra, Prof Frimpong-Boateng asked farmers to observe improved sanitation in the cropping environment and comply with regulatory requirements to ensure water quality.

The meeting was to share with the farmers the findings on investigations into the problem of recent high fish mortality at fish farms on the Volta Lake and the Lower Volta.

The Minister disclosed that laboratory observations by the Environmental Protection Agency, alongside tests carried out by the Fisheries Commission and the Ghana Standards Authority, did not find evidence to support the initial suspicion by farmers of poisoning from the discharge of deleterious materials into the lake or the Lower Volta.

“We observed that a combination of factors including the proliferation of bacteria have contributed to the deaths of fish so far recorded. The situation is compounded by the illegal introduction and proliferation of the Asian GIFT strain of tilapia on several farms within the Volta River system,” he said.

Reports by Independent genetic analysis to the Ministry, he stated indicated that the illegal introduction of the Asian GIFT strain had occurred alongside the emergence of a new strain of Streptococcus bacteria with genetic signatures similar to the Chinese strain of Streptococcus agalactiae.

This strain of bacteria Prof. Frimpong-Boateng said was resistant to the vaccines used against the locally occurring strain of streptococcus agalactiae and that the resilience of the Akosombo strain to bacterial infection was compromised by the illegal crossing of the local strain with foreign ones.

“We note that this is the most critical factor accounting for the massive death of fish on the farms in recent months,” he added.

The Minister announced that the Environmental Protection Agency has initiated investigations to identify all farms that have the Asian GIFT or the Akosombo strain introgressed with Asian strains in their custody or offering it for sale to farms.

“We are determined to weed out those farms that have flouted our laws and are culturing and distributing unapproved strains of tilapia, in order to safeguard the aquaculture industry,” he noted.

Prof. Frimpong-Boateng urged all farmers to support the governments’ efforts by volunteering leads to those farms that were keeping the Asian GIFT or the Akosombo Strain with introgressed GIFT genes.

Farmers at the meeting applauded the steps being taken by the government to address the situation due to the harm the situation was causing at the various farms.

They asked the government to strengthen its enforcement role and take punitive measures against any farmer who flout the regulation especially the farm that introduced that strain into the lake.

Farmers wondered why authorities were silent although the farms with that illegal strain were known.