As soon as TRM posted the warning of an algae bloom from Taupo Council (below) a reader commented:
“Farmers and the high fertiliser levels they use have no doubt contributed to lake algaes.”
This was also indicated on DOC facebook as follows:
“Taupo fishery scientist Michel Dedual has begun analysis of the data collected from a recent echo-sounding survey, and early indications suggest productivity (smelt and zooplankton) is high this year, especially at the southern end of the lake.
Smelt are the main source of food for Lake Taupo trout, so it follows that high numbers of smelt will help trout achieve good growth rates and recover well from spawning.”
Meanwhile DOC’s analysis from their main trout measuring device – the Waipa Trap in the upper Tongariro River – confirms:
“… fish trap data confirms that the average size of trout this year is the highest we’ve seen since 2006”
Taupo anglers are so perceptive and immediately started joining the dots re the food chain… i.e.
Considering the evidence of a bloom of lake algae or excessive marine weed growth following high water temperatures (high for December around 26 degrees), whilst at the same time DOC are reporting the best season for trout condition (average 3.6 pounds) for many years, following their report of higher than usual productivity of smelt and zooplankton, then the coincidence is almost too obvious to ignore…
Previously some brash fishy commentators, who know how the food chain works, had suggested top dressing the lake to promote the food chain to improve trout size (?) but that was unacceptable when the Government had spent $Millions trying to keep Lake Taupo 100% pure by trying to limit stock numbers on large farms around the western shores. But now the increase in nutrients may have been achieved from nutrients run-off from farms.
Watch this space…
Dense mats of potentially toxic algal species have been found at five sites around Lake Taupō. That’s prompted a warning for the public to avoid swimming in affected areas and any contact with algae blooms that may be on shore.
Testing of samples collected by our scientists has confirmed the presence of potentially toxic algal species, including Phormidium, at areas within Five Mile Bay, Acacia Bay, the main lake front in Taupō, Whakaipo Bay and Kinloch Beach.
People are advised not to paddle, wade, swim, or participate in any recreational activity that might involve any direct contact with the algal mats or swallowing of affected lake water. Parents should ensure young children do not come into contact with algal mats in the water or on the shoreline.
Dogs are especially vulnerable, so people should keep their pets and livestock out of the water and off the shoreline in the known affected areas or where the algae is visible.
Contact with algal mats can cause symptoms such as skin rashes, stomach upsets and respiratory symptoms such as triggering of asthmatic attacks. If material from algal mats is swallowed it can cause neurological symptoms such as numbness and weakness, visual symptoms and, in severe case, affect the ability to breathe.