You know its summer when the sea lettuce collections start along the Otumoetai and Matua foreshores.

The first collection of 800 tonnes from Matua and Otumoetai was made last week, co-ordinated by the Bay of Plenty Regional and Tauranga City Councils.

But the regional council's weed man, technical Advisor Bruce Gardner says they are not expecting huge volumes of sea lettuce this summer.

'It's normal for sea lettuce accumulations to wash ashore in Tauranga Harbour, especially when contributing wind and tidal conditions align,” says Bruce.

'Despite the build-up at Matua, growth levels throughout the harbour so far are below the long term average for this time of the year and a neutral El Nino/La Nina weather pattern is forecast for this summer.

'So at this stage we've got no reason to expect any exceptionally large blooms this summer.”

Sea lettuce is a native algae that flourishes in clear, nutrient-rich water and sea temperatures of around 15-20°C, so Tauranga Harbour is a perfect place for it to grow, says Bruce.

'But it can be a nuisance to people when it washes up on the beaches.”

The councils will continue to collect nuisance accumulations from popular beaches as needed over summer. The councils have a three-pronged approach to managing sea lettuce.

'We're reducing nutrient inputs to the harbour by working with land, business and infrastructure owners to clean-up land run-off, we're funding research projects through the University of Waikato Coastal Science Chair, and we collect nuisance accumulations from busy beaches. No untreated waste discharges have been allowed into the harbour since the 1990s,” says Bruce.

Sea lettuce concerns can be reported to Bay of Plenty Regional Council's Pollution Hotline on 0800 884 883 or Tauranga City Council on 07 577 7000. Further information about sea lettuce in Tauranga Harbour is available at www.boprc.govt.nz/sealettuce.