Walvis: Washed-up fish not toxic
ELLANIE SMIT
WINDHOEK
Analyses of collected water samples at Walvis Bay and harbour areas have concluded that algal blooms present in the water were caused by a non-toxic species.
This after many dead or dying mullet fish and other marine species were recently observed in the Walvis Bay lagoon area.
Fisheries ministry executive director Annely Haiphene said the fish therefore poses no harm to the public, provided that they are still fresh.
The ministry previously said satellite images showed algal blooms along the central Namibian coast and water temperatures around 25 degrees Celsius.
This, Haiphene said, is usual for this time of the year, because of weakened south-westerly winds and no active upwelling taking place, leading to local warming of the water as well as the intrusion of warmer oceanic water into the coastal areas, which are favourable for algal blooms.
The ministry said algal blooms can be toxic, but even non-toxic species strip the water column of oxygen when decaying and can lead to low oxygen events that are sometimes exacerbated by sulphur eruptions.
Low oxygen conditions are presumed to have trapped the fish in the lagoon and along the coast, causing them to die and wash out when the water level drops during low tide.
Lobsters too
Haiphene added that with the inflow of the Swakop River into the ocean, the dying of lobster and other marine species has been observed.
“This are due to a combination of factors including the mud clogging the gills of fish and crustaceans, exposure to fresh water and low oxygen.”
She said although these species do not contain toxins, the ministry does not encourage consumption of washed-up organisms as they could have started decaying and are therefore unfit for human consumption.
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WINDHOEK
Analyses of collected water samples at Walvis Bay and harbour areas have concluded that algal blooms present in the water were caused by a non-toxic species.
This after many dead or dying mullet fish and other marine species were recently observed in the Walvis Bay lagoon area.
Fisheries ministry executive director Annely Haiphene said the fish therefore poses no harm to the public, provided that they are still fresh.
The ministry previously said satellite images showed algal blooms along the central Namibian coast and water temperatures around 25 degrees Celsius.
This, Haiphene said, is usual for this time of the year, because of weakened south-westerly winds and no active upwelling taking place, leading to local warming of the water as well as the intrusion of warmer oceanic water into the coastal areas, which are favourable for algal blooms.
The ministry said algal blooms can be toxic, but even non-toxic species strip the water column of oxygen when decaying and can lead to low oxygen events that are sometimes exacerbated by sulphur eruptions.
Low oxygen conditions are presumed to have trapped the fish in the lagoon and along the coast, causing them to die and wash out when the water level drops during low tide.
Lobsters too
Haiphene added that with the inflow of the Swakop River into the ocean, the dying of lobster and other marine species has been observed.
“This are due to a combination of factors including the mud clogging the gills of fish and crustaceans, exposure to fresh water and low oxygen.”
She said although these species do not contain toxins, the ministry does not encourage consumption of washed-up organisms as they could have started decaying and are therefore unfit for human consumption.
[email protected]
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