Volunteers from the Guardians of Kāpiti Marine Reserve have been undertaking regular shoreline clean-ups at the northern end of Kāpiti Island as part of a nationwide beach litter monitoring programme called Litter Intelligence.
Developed and led by Auckland based charity Sustainable Coastlines, the Litter Intelligence programme provides communities with the skills, knowledge and equipment to collect scientifically rigorous beach litter data, and aims to provide insights and inspire action for a litter-free New Zealand.
Launched in May 2018, the programme is funded by the Ministry for the Environment's Waste Minimisation Fund and works in close collaboration with Statistics New Zealand and the Department of Conservation.
As New Zealand's first national litter database, Litter Intelligence is helping build a better understanding of the problem.
The Guardians were one of the first community groups in the country to get involved in the programme, and have now established a regular litter monitoring and clean-up programme, completing three clean-ups at the shoreline at the north end of Kāpiti Island over the past 12 months.
And the good news is that these efforts have led to a significant reduction in the amount of litter on the island.
"The first trip was a bit of a shock for our clean-up team, with a significant amount of litter visible along the shoreline, including lost fishing gear, rope, nets, mussel buoys, processed timber and household and food related single use plastic waste strewn along the shoreline adjacent to the reserve," Guardians chairman Ben Knight said.
"But once we had done the initial clean-up, we have seen a noticeable reduction in the amount of litter found during each of the repeat surveys that we conduct every three months.
"Of concern is the amount of plastic debris that appears to be being transported to the island by black backed seagulls, with single use food handling gloves, food wrap, cotton buds and a large amount of chicken bones found in the areas where the gulls roost and nest.
"We suspect the seagulls are scavenging this litter on the mainland and carrying it back to the island in their stomachs each night when they return to roost.
"While the seagulls are able to regurgitate this indigestible waste out of their stomachs, it is unclear what impacts this is having on the seagulls or their chicks.
"Internationally, the consumption of plastic material by seagulls is correlated with lower reproductive rates, so it is a concern to see this also occurring in our beautiful part of the world.
"Litter is not only ingested by seabirds, but items such as lost fishing nets, line and rope also present an entanglement hazard to both seabirds and marine mammals, and it is therefore important that fishers make every effort to ensure their gear s not lost into the environment or otherwise impacting on our local seabirds and marine mammals such as seals and dolphins."
Knight said a dead pied shag was found entangled in fishing line with a hook deeply embedded in its leg.
"While we can't be sure this was the cause of death, it seems highly likely and would most certainly have led to considerable suffering for this protected species.
"We can all play a part in helping to keep the local beaches and coastline that we all love beautiful.
"Buying reusable rather than single use or recyclable products, disposing of litter correctly and picking up litter off the streets and beaches before it makes its way out to Kāpiti Island are all simple things that we can do that make a big difference."
To view the data from the most recent litter surveys conducted at Kāpiti Island and to get involved in this programme check out https://litterintelligence.org