Dozens of ducks have been found sick and dead around some of the city's wetlands due to botulism and people feeding them bread are only making the situation worse.
Auckland Council has been made aware of a number of dead ducks at Awaruku Wetlands in Long Bay and Stredwick Reserve in Torbay that were most likely killed by avian botulism.
Auckland Council general manager Healthy Waters Craig Mcilroy said the hot, dry weather causes the botulism toxin-producing bacteria naturally present in the ponds to grow and when the water levels are low it makes it easier for the ducks to come in contact with the sediment or bugs containing the botulinum toxin.
The ducks slowly become paralysed and die.
The situation was made even worse when ducks were fed bread because it rotted in ponds and helped the botulism bacteria grow, Mcilroy said.
Torbay resident Jeanine Oxenius first came across two sick ducks in the Long Bay Reserve on her morning walk last Monday and has since taken 20 ducks 40km away to the bird rescue centre in Green Bay where they were given medication and nursed back to health.
She also fished out 30 dead ducks from the pond.
Oxenius had resorted to dumping the dead ducks by council signs or on the footpath after becoming frustrated council was doing nothing about it.
Along with the ducks, Oxenius had also retrieved dead eels which she believed were dying the same way.
"You wouldn't believe what I've seen last week. It's just heartbreaking..."
She believed council should be doing more to clean up the water.
The council had also been alerted to dead ducks at Te Koiwi Park in Papakura, Hayman Park in Manukau, Chelsea Estate Heritage Park in Birkenhead, Wetlands Reserve in New Lynn, Western Springs Lakeside Park in Grey Lynn and Stonefields Wetlands in Stonefields.
The council had now increased the number of inspections it made to the most high-risk reserves to every second morning and was visiting others where there had also been reports of dead ducks to three times a week.
"We are closely monitoring the situation and have increased our inspections of the area, so that we can remove any dead birds to help stop the spread of botulism," McIlroy said
People were also being urged not to feed bread to the ducks because sick or dead ducks could have a detrimental effect on overall water quality.
"It is better to encourage ducks to forage naturally."
Anyone who visits the reserves and sees a dead duck should report it to council on 09 301 0101.