New Zealand's native marine species are under threat, land activities are polluting the country's marine environment and climate change could have a serious impact on oceans and coasts, a new report has found.
It states there had been a decline in native marine species and habitat due to human activity, with 90 per cent of seabirds, 80 per cent of shore birds and 22 per cent of marine mammals threatened with or at risk of extinction.
Litter and plastic was found "everywhere" in the marine environment - with plastic the most common litter, making up 61 per cent, while cigarettes made up 11 per cent.
A survey of 44 areas in New Zealand by Sustainable Coastlines found the dirtiest areas were Hamilton's Gap Beach near Auckland, Wellington's Petone Beach and Northland's Hatea River.
Volunteer Des Watson of Kiwis Clean Aotearoa, a group attempting to rid New Zealand's coastlines of rubbish, told 1 NEWS that the most common type of rubbish was hard plastic fragments.
"There’s a lot of rubbish heading up the West Coast from Fox Glacier, I started noticing micro-plastics, little beads again and hard plastic fragments.
"I've seen some beautiful coastline, I've seen lots of plastic, I think in the South Island I collected roughly about 15 tonne of rubbish."
The report warned of the increased rate of sea-level rise, ocean acidity and temperature caused by a lift of global concentrations of atmospheric greenhouse gases resulting in "unprecedented change in our oceans".
"Warmer seas affect the growth of even the smallest things in the ocean like plankton which can impact the whole food web," the report stated.
"Some temperature-related changes in individual species and fish communities have been observed. Roads, bridges, coastal communities, and habitats are at risk from flooding and sea-level rise."
The report, 'Our marine environment 2019' was written by the Ministry for the Environment and Stats NZ. It said in 2017, the marine economy brought in $7 billion and employed more than 30,000 people.
Secretary for the Environment Vicky Robertson described the oceans in New Zealand as a "a giant sponge against the effects of climate change".
"The warmer the water gets, the less able it is to absorb gases like carbon dioxide. The growth of species in the oceans is affected, and coastal communities and habitats are at risk from flooding and sea-level rise."
Government statistician Liz MacPherson and Ms Robertson wrote in the report that "the data shows some of the effects are worsening, and faster than first thought".
"This is especially true of the impacts of climate change and pollution on our marine environment.
"We trade on a reputation of pristine beaches and clean sparkling water, and visitors from other countries revere them, but we have seen in this report that this is not always the case," Ms MacPherson said.
"By taking action now, collectively and even in small ways, we can hold on to that pride and protect our coasts and oceans for our mokopuna – our children and grandchildren."