THE Fisheries ministry yesterday warned members of the public against eating mussels from Walvis Bay because they have been poisoned during production.
In a statement yesterday, permanent secretary Moses Maurihungirire said that mussels samples from the Walvis Bay Aquaculture Production Area have tested positive for biotoxins.
He said this came to light during the recent sampling and testing by the Namibian Standards Institution (NSI) on the 16 Januray.
"The latest results from mussels samples that were submitted for testing indicate the presence of diarrhetic shellfish poisoning (DSP) at a higher level than permissible in these samples and therefore it is unsafe to collect or consume mussels until further notice by the ministry," cautioned Maurihungirire.
The results from the second re-testing are expected by the end of next week, he said.
In a letter to mariculture farmers this week, the ministry warned that mussels may not be harvested in the affected area for human consumption, depuration or relaying.
There is one company at Walvis Bay that farms with mussels namely Kuiseb Marine Farming, according to the ministry.
Acting deputy director for aquaculture within the ministry Frikkie Botes told The Namibian yesterday that although the current prevalence of DSP was only detected in mussels from the Walvis Bay production area, oysters and clams can also be affected.
"Harmful algal blooms (HABs) are completely natural phenomena and occur throughout the world and it can threaten human life by making seafood toxic to consumers and by direct effects on marine life. Some of the phytoplankton species e.g. dinoflagellates like Dinophysis can produce biotoxins that causes diarrhetic shellfish poisoning (DSP)," he said.
He added that the ministry has a water quality monitoring programme in place whereby aquaculture production areas are monitored on a weekly basis.
One of the aims of this monitoring is to determine the relative abundance of toxic species present in the local waters, according to him.
"Water samples are collected on a weekly basis and phytoplankton species in the samples are then identified under a microscope," he said. "Since 2012 to date, there has been 14 positive results on mussels due to DSP in Aquapark 1 at Walvis Bay."