Measuring the true scale of Northland’s litter

A project designed to prevent litter from reaching Taitokerau’s coastal environment through stormwater drains has captured a staggering 21,006 items over the past year.

Northland Regional Council Resource Scientist – Coastal, Richard Griffiths with six months’ rubbish collected in a LittaTrap from Herekino St in Whangārei. The LittaTraps, a net which fits inside stormwater grates and captures litter as it is washed into drains, were installed at 51 sites around Northland in late 2020 and monitored quarterly for a year.

Plastic accounted for 71.1% of the total waste collected in the LittaTraps with cigarette butts and filters the most common single items with a whopping 6887 collected over the year.

The project to protect our waterways is part of a multi-agency response led by Northland Regional Council and also involves the region’s three district councils, Northland District Health Board and local businesses.

Dr Manue Martinez from Maunga to Moana (M2M) Consulting says the highest volume of rubbish was at a Whangārei city centre carpark which captured a total of 2172 items in 12 months, which is the equivalent of 352 items per hectare per day.

“This amount of waste over the duration of a year would lead to a total of 128,480 items per hectare per year – that’s a lot of rubbish just being dumped on the ground,” Dr Martinez says.

NRC’s coastal scientist Richard Griffiths estimates almost six million litter items are released into the harbour from the Whangārei stormwater network every year, the vast majority being plastics.

“The best thing Northlanders can do to prevent rubbish from making its way to the sea via our stormwater systems is simply not dropping litter in the street in the first place,” Mr Griffiths says.

He is encouraging local businesses to consider installing and monitoring a LittaTrap in grates and drains near their own premises to help make a permanent difference.

Litter and plastic is one of the biggest pollutants of our oceans and can have damaging, or even lethal effects on animals that ingest it or get entangled in it. It also affects the aesthetics and amenity value of our coastal environments.