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Sea Lettuce

sea lettuce

Sea lettuce is a naturally occurring green algae that is native to New Zealand.  Sea lettuce can cause problems for the community when it grows during summer months and is deposited on beach and foreshore areas in large quantities.

For more information about sea lettuce in Tauranga Harbour read our factsheet.

Sea lettuce 'blooms' can affect the way the harbour looks, and how people can use the harbour for business and pleasure. 

When it decays, sea lettuce produces an offensive sulphur odour. It can drift around the harbour and nearshore coastal waters and interfere with fishing nets and lines.  It can also affect commercial shipping at the Port of Tauranga, wrapping around ship propellers and blocking cooling water intakes.

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 which affect water temperature and natural nutrient levels.

Research by Regional Council has shown that large sea lettuce blooms in Tauranga Harbour are a natural event that is linked to the El Nino weather pattern.

Regional Council works with Tauranga City and Western Bay District Councils to remove nuisance accumulations of sea lettuce from high use public areas around the Tauranga Harbour. Watch the New Zealand Herald video to find out how the Regional Council is managing sea lettuce.

Read the report on Sea Lettuce and Nutrient Monitoring in Tauranga Harbour 1991-2010.