Fencing for stock exclusion and riparian planting has started at Whakakī Lake, north of Wairoa, one of six areas identified as an environmental hotspot in the Hawke's Bay Regional Council's annual plan last year.
The council allocated $1 million for freshwater improvement work across the six areas, with work at Whakakī Lake focused on reducing the amount of sediment coming into the shallow, coastal water body from the surrounding hill country.
With a maximum depth of one metre, this had led to a decline in water quality over past decades and in March this year, cyanobacteria growth was said to be 50 times higher than the limit considered safe for contact recreation.
The potential for the toxins from this algae to accumulate in fish tissue, including that of a thriving tuna population, was also being explored.
Alongside local farmers, including Hereheretau Station farm manager Dick Finney, efforts to reduce this sediment loss and keep stock out are now under way, including a 1km stock exclusion fence being built along the Rahui Channel, which connects the lake to the sea.