Health Warnings Lifted at Lake Rotoiti and Lake Okaro
Recent tests conducted by Environment Bay of Plenty confirm low cell counts of cyanobacteria (blue-green algae) at Lake Rotoiti (except Okawa Bay where algal bloom continues) and Lake Okaro, so the health warnings have been lifted.
‚ÄúAlgal numbers have finally decreased to levels where any risk to the public from contact with the water is minimal,‚Äù says Medical Officer of Health Dr Phil Shoemack. ‚ÄúUnfortunately the bloom is still present in Okawa Bay and throughout much of Lake Rotoehu, so health warnings remain in place.‚Äù
Cyanobacteria have bloomed in Rotorua lakes every summer since the early 1990s.
‚ÄúThe 2004-2005 summer hasn‚Äôt been as bad as in recent years but health warnings have still been in place for several months at some sites,‚Äù he says. ‚ÄúOkawa Bay seems to behave almost as if it were a separate lake, completely cut-off from the rest of Lake Rotoiti.‚Äù
Cyanobacteria are found at low levels in fresh water around the globe, but they have the capacity to multiply to bloom levels in warm, calm, sunny weather and in water plentiful in nutrients, especially nitrogen and phosphorus. They also can produce a range of toxins, which are responsible for most of the associated health problems. There have been several reports over the past few months of people who have experienced health symptoms after contact with lake water.
‚ÄúSymptoms have included skin rashes, tummy upset, and more general malaise,‚Äù says Dr Shoemack.
Environment Bay of Plenty is consulting widely on options to improve the water quality of the Rotorua lakes and it‚Äôs hoped that these efforts will see an improvement in years to come.
For more information:
Medical Officer of Health
Dr Phil Shoemack
Toi Te Ora Public Health
07 577 3303
027 277 8670