The Environmental Protection Agency (EPA) has also ruled out poisoning as the cause of death in the varying species of fish that were washed ashore a few weeks ago.
Speaking to Citi News, the Executive Director of EPA, Henry Kokofu, also backed the earlier reports that stress factors caused the death of the aquatic animals.
"We've ruled out the incidences of chemical spillage or poisoning because if that had been the case, it would have never been selective. It would have killed all the animals that were washed ashore," Mr. Kokofu said.
The EPA assessment is in line with the Fisheries Commission's preliminary investigations which indicated that stress factors caused the deaths.
The fish were found along the shores of the Osu Castle beach in Accra and ashore at the Axim-Bewire beach in the Nzema East Municipality.
There were some concerns about the state of the fish since some residents in the affected areas took some of the fish for consumption, in spite of cautions from experts.
Shedding more light on the stress factors, Mr. Kokofu noted that oxygen deficiency, heat and fatigue contributed to the fish deaths.
"We do suspect greatly that there have been variations in oxygen content in the body of the sea that the animals found themselves in."
"These animals, particularly the dolphins, are known to be deep-dwelling [animals], so they will come up at times for fresh oxygen and other things when there are deficiencies at the bottom of the sea," he explained.
"March is the warmest month in Ghana and once the temperature changes, so does the water temperature, and it is believed that at the particular point in time, there was some oxygen deficiency under the waters."
Mr. Kokofu further noted that the fish were not native to Ghana's waters and had been affected by migration exertions.
"You can imagine fatigue will also set in and if they are experiencing oxygen shortage, they then get into stressful conditions."