AN environmental disaster occurred in Karoi last week after scores of different fish species died when suspected mongers applied poison in dam water in a bid to increase fish catches.
Fears abound that rogue dealers could sell the dead contaminated fish to unsuspecting nearby communities, thereby posing a health hazard.
Although the extent of the ecological damage and long-term effects wrought by the application of the unidentified noxious substance could not be immediately ascertained, the action had devastating effects.
The Environmental Management Agency (EMA) Mashonaland West provincial environment education and publicity officer, Munyaradzi Nhariswa confirmed the incident that occurred at Watson Farm, Hurungwe district in Karoi.
"EMA received a report of suspected fish poisoning in Watson Dam at Watson Farm, Hurungwe District. The incident was reported to have occurred on the eve of September 12, 2023 and a police report was made on September 14, 2023.
"The agency together with the Veterinary Services Department (VET) visited the place for assessment and collection of samples on September 14, 2023," said Nhariswa.
The impact of the suspected poisoning was dire.
"During inspection, the team noted dead pale fish along dam shores, and some fingerlings with clamped fins, and gasping at the surface," he added.
He noted the floating fingerlings were first spotted on the morning of September 13, 2023.
Community elders, who later visited the dam site, confirmed an unpleasant chemical smell they suspected to be maize-treating pills.
Water samples were taken to the EMA laboratory for analysis and results are pending. Also, the veterinary department extracted samples of dead fish for postmortem and further analysis. By time of publishing, results were also still pending.
Meanwhile, the local community was directed to desist from using the water for any purpose pending the outcome of lab results.
NewZimbabwe.com visited the site where villagers revealed that two discreet men suspected to be fishmongers were spotted around the dam on the eve of September 12, 2023, and were chief suspects.
"The two unidentified men are the ones who did this hideous thing of polluting our water body used by an entire community just for the love of money and at the expense of the breeding fish," lamented Shorai Kamuhonde, a recreational fisherman at the affected dam.
Nhariswa warned members of the community that it is a punishable offence to pollute an aquatic habitat.
"As EMA, we continuously remind communities that the discharge or application of any poison or toxic, noxious or obstructing matter, radioactive waste or other pollutants into the aquatic environment in contravention of water pollution control standards is prohibited.
"Any person who violates these regulations shall be guilty of an offence and liable to a fine not exceeding level fourteen, whichever is the greater, or to imprisonment for a period not exceeding five years, or to both such fine and such imprisonment.
"Polluted water is the world's biggest health risk and continues to threaten both quality of life and public health in the country and requires our collective effort to address it," said Nhariswa.
A 2015 study showed that when fish larvae are exposed to pesticides through water contamination from runoff, they can develop swimming abnormalities as they grow, making them easy targets for prey and impacting their survival rate.
Fish can be directly or indirectly impacted by pesticides while some long-term exposures trigger mutations in developing fish larvae, while acute exposure can result in instant death.
Sign up for free AllAfrica Newsletters
Get the latest in African news delivered straight to your inbox
The liver, kidney, brain and gills of exposed fish are extremely vulnerable to chemical exposure.
Fish species are also sensitive to endocrine disruptors. In 2005, researchers in British Columbia, Canada, demonstrated that biological changes induced by sublethal exposure to pesticides include inhibition of important enzymes and growth delay.
In the event that one unsuspectingly consumes poisoned fish, they exhibit signs of an allergic reaction that occurs within minutes to hours.
Symptoms usually occur within one to 24 hours of eating a toxic fish and include, rashes, vomiting, diarrhoea, abdominal or stomach cramps, headaches, fatigue and fainting.
Fish provide food services for humans and other wildlife and they also avail benefits for citizens through direct financial gain or recreational enjoyment.
