Sea lettuce clean-up along coastlines in Tauranga has been taking place over the past few weeks.

Sea lettuce is a naturally occurring green algae native to New Zealand. There are about five different species of it in Tauranga Harbour and with its shallow flats and channels, it is perfect for sea lettuce growing conditions.

'Sea lettuce varies in abundance from year to year and place to place. Its presence is most strongly influenced by uncontrollable factors such as wind, tides and coastal currents,” says Bay of Plenty Regional Council principal advisor, land and water, Jackson Efford.

'Clean-ups are therefore scheduled at short notice, based on regular monitoring throughout the summer by the Bay of Plenty Regional Council and Tauranga City Council to identify problem areas as they develop.

'Sometimes changes in tide and wind can quickly remove sea lettuce from beaches and shift it out into the harbour or ocean, avoiding the need for a clean-up.”

Jackson says once the sea lettuce is collected, it is then rinsed, dewatered, and taken to a commercial composting facility where it's washed and processed along with other green waste.

He says there is no risk to the public's health from the sea lettuce.

'In the water it can drift around the harbour and nearshore coastal waters, interfere with fishing nets and lines. The main issue with sea lettuce is when the beach cast sea lettuce builds up and starts to rot; the hydrogen sulphide that is released results in a nasty odour.”

Aside from coordinating sea lettuce clean ups, the Bay of Plenty Regional Council works with land owners, business owners, local councils and the wider community to reduce nutrients.

'Nutrient sources such as from agricultural runoff and nutrients that drain through the soil and into groundwater, eventually entering the harbour, can contribute to sea lettuce blooms.

'The council also invests in research to further understand the problem, model the likelihood of sea lettuce blooms, and identify viable management options.”

Watch the video above to find out more about the sea lettuce clean ups and how they work.