Hitting the sweet spot: why regular beach litter surveys matter

Hitting the sweet spot: why regular beach litter surveys matter

In 2023, citizen scientists put on their pink vests and surveyed the litter on 216 beaches around the country for our national litter database, Litter Intelligence. Every survey contributes meaningful data, but more frequent surveys give us superior insights into the litter problem as it presents on the local coastline.

Beaches vary in their physical characteristics, such as shape, substrate, and wind exposure, which means litter acts differently on different beaches. On some, it gets washed or blown away quickly, while on others, litter can end up in sheltered spots and stay there for a very long time.

Every survey, the beach is essentially ‘reset’ — the monitoring group removes all the litter, providing a clean slate for the litter to accumulate for the following survey. This is why the data from the very first survey at a given site isn’t representative of things to come: we don’t know how long the litter there took to accumulate. A beach with very little litter arriving may appear very ‘dirty’ because its characteristics mean it is good at retaining litter. Likewise, a beach that appears relatively clean may in fact receive a decent amount of litter, but the wind or tides take it away.

Citizen scientists conducting a litter survey at Tāmaki Makaurau Auckland’s Little Shoal Bay, July 2023.

Citizen scientists measure the litter problem in order to show how litter affects our coastlines long-term. We need this data to be able to observe variability and change over time according to seasons or weather patterns. 

Doing a survey every three months allows us to capture the ‘litter accumulation rate’ for the monitoring site. Each survey is a reflection of the long-term balance between arrival and departure of litter. This frequency also allows us to calculate litter ‘flux’, which is a measure of the rate of accumulation of litter over a set period of time, taking into account the period between surveys.

Citizen scientists auditing the litter. Little Shoal Bay, Tāmaki Makaurau Auckland, July 2023.

Citizen scientists who have been at it for a while will know it’s not always possible to do a survey at the three-month mark — some sites aren’t accessible all year round, the weather gets in the way, and sometimes people just aren’t available to do them. The good news is that less frequent surveys still provide useful data if we adjust it for the relevant time period.

However, three months is the sweet spot between solid data collection and manageability. This frequency aligns with the United Nations Environment Programme and Intergovernmental Oceanographic Commission guidelines on monitoring marine litter. More frequent surveys would obviously give us richer data, but we designed the Litter Intelligence methodology to be manageable by volunteers who are generously donating their time to tackle the litter problem.

Media release: 7 July 2022

With more than 15,000 kilometres of coast, Aotearoa has one of the longest and most stunning stretches of coastline of any country. On a three monthly basis, Litter Intelligence groups across the country visit their local stretch of coastline to record waste findings. This Plastic Free July, award-winning charity Sustainable Coastlines is celebrating the power of this data, and the trailblazing heroes who help collect it: citizen scientists. Now, the efforts of these dedicated individuals are contributing to a Wellbeing Indicator for Stats NZ.

“Plastic Free July is a great time to motivate the masses to be part of solutions to plastic pollution”, says Sustainable Coastlines Co-Founder Camden Howitt. “We created Litter Intelligence to inspire and inform better decisions for a world without litter, and we’re proud that our work with Stats NZ takes us another step forward for better solutions to the plastic crisis.”

Launched in 2018, Litter Intelligence is New Zealand’s first and only national beach litter database. The data collection methodology is based on United Nations Environment Program guidelines and was co-designed alongside the Ministry for the Environment, Stats NZ and the Department of Conservation. The detailed training, combined with user-friendly technology, allows environmental data to be submitted by communities at the highest standard, so it can be used by government reporting, which now include the Wellbeing Indicators for Ngā Tūtohu Aotearoa – Indicators Aotearoa New Zealand.

Litter Intelligence data collection in action.

“Stats NZ has partnered with Sustainable Coastlines over the past few years on Litter Intelligence, supporting good data management practice, and open data access,” says Stats NZ Environmental and Agricultural Statistics Senior Manager, Michele Lloyd.

“This data was first used as a case study in the Our Marine Environment 2019 report. I am pleased to see that this data will continue to be used to add value to Ngā Tūtohu Aotearoa – Indicators Aotearoa NZ. This is a great example of how working together with external partners can provide additional data to reduce data gaps for New Zealand.”

Indicators Aotearoa New Zealand was developed by Stats NZ as a source of measures for New Zealand’s wellbeing and aims to help monitor progress around social, economic, cultural and environmental wellbeing. The wellbeing indicators are built on international best practice, and are  tailored to New Zealand. Litter Intelligence‘s citizen science data is now informing Wellbeing Indicators, in particular the ‘Waste flows in waterways and coastal marine environments’ indicator which demonstrates the amount of waste discharged into waterways and coastal areas around NZ each year.

‘Citizen science’ refers to the public participation in scientific research — it is a non-traditional form of data collection and is already contributing significantly to the scientific community. Thanks to the citizen scientists involved in the Litter Intelligence programme, government agencies, businesses and communities now have better insights into the health of our coasts and therefore, the power to find appropriate solutions.

Marilyn Scott’s Litter Intelligence citizen science group, monitoring the Waitangi Estuary in Hawke’s Bay.

“This announcement shows the true power of citizen science. We’re incredibly proud that members of our community can contribute towards environmental reporting that informs better decision making,” says Howitt. “Thanks to the continued dedication and hard work of our citizen scientists, we’re now able to contribute to the wellbeing indicators of our own home, right here in Aotearoa”.  

Long-time citizen scientist Marilyn Scott says people often feel disempowered, when it comes to the health of the environment, but since taking the role of a citizen scientist she feels like she’s part of the solution. 

“Our citizen science group started in June 2019 and is made up of 20 dedicated individuals who look after the Waitangi Estuary in Hawke’s Bay. The beauty of this work is in seeing the efforts coming together throughout Aotearoa and the direct action that comes from it. Sure, you see disappointing things of course, like the countless pieces of single-use plastic, or the horrid oesophagus clips on our coasts but the great thing about this involvement, is the fact that there is a further layer here which is ironclad data that can be used for government reporting and policy change. It’s great to think we’re helping restore Papatūānuku and therefore part of a bigger picture, and I for one, am delighted to be involved”.

“We’re proud to celebrate Plastic Free July by acknowledging the mahi of our fellow Kiwis,” adds Howitt. Their dedication, commitment, and volunteering of their time – over 16,000 hours to date – is an epic contribution to the health of our moana”. 

Visit https://statisticsnz.shinyapps.io/wellbeingindicators/ for more information 

To learn more about Litter Intelligence please visit:
https://litterintelligence.org

This month, June 2022, the team at Sustainable Coastlines is thrilled to welcome Jennifer McKnight, our first international volunteer after a two-year hiatus due to border closures.

To celebrate the re-establishment of our IVHQ (International Volunteer Headquarters) programme, and to recognise National Volunteer Week, 19–25 June, we chatted to Jennifer about her motivations for supporting Sustainable Coastlines, what she loves about Aotearoa, and her recommendations for Plastic Free July.

Jennifer at the Sustainable Coastlines education and events space, The Flagship in Tāmaki Makaurau’s Wynyard Quarter.

Hey Jennifer, can you tell us a bit about yourself?

“I’m from California, where I work as a tax accountant. I love travelling and spending time outdoors or at concerts when I can. In the past year I’ve been spending a lot of time at the climbing gym and taking kickboxing classes. A lot of my work time is spent sitting down, so any time off the clock I like to get out and move!”

What made you want to come to New Zealand?

“This is actually my third time here! I first came to New Zealand in 2015 when I was in my early twenties. That first trip really helped me to step out of my comfort zone — I got into all the outdoor activities on offer: rafting, ziplining, rappelling down waterfalls. I loved spending time in nature, and that carried through to my other travels and my life back home. But because this was where it all began, I keep wanting to return to New Zealand — the environment really resonated with me. It gave so much to me.”

What about the environment here resonates with you so much?

“It’s beautiful. It reminds me a bit of home, where there’s a bit of everything relatively close. I especially love the waterfalls and forests. I love it any time you can respectfully treat nature as your playground, and that’s very easy to do here.”

Where’s your favourite place in New Zealand?

“That’s so hard to say, it’s all so nice. On my first trip here, I went rafting in Rotorua down the Kaituna River. It was my first time white-water rafting; it was so fun, and the scenery was so beautiful. It sticks in my mind as one of the most pure experiences in my life. So yeah, I’d have to say the Kaituna River.”

A rapid on the Kaituna River.

What made you want to volunteer with Sustainable Coastlines?

“Because I’ve gotten so much from New Zealand’s natural environment, I really wanted to give back to it. I wanted to put some love back into a place that has already given me so much love, and the work SC is doing really falls in line with that.”

What kind of impact do you see Sustainable Coastlines as having?

“The other day we were laying out plants for a tree-planting day run alongside Auckland Council. There were 10,000 of them, which looked like a lot, and it was hard to imagine them all planted. We were at the planting the next day, and with all the volunteers, the trees were planted, no problem. So Sustainable Coastlines is obviously really good at bringing people together and making a collaborative impact. It’s really great for people to have the chance to work together as a community with a shared goal like that.”

“I know I’ll be back in New Zealand one day, and I’m looking forward to seeing those trees we planted all grown up. Which is also something that’s probably really satisfying for the locals.”

Te Hira Mayall-Nahi, Sustainable Coastlines’ IVHQ Coordinator, and Jennifer McKnight, at Puhinui Reserve in June 2022.

Plastic Free July is coming up — have you got any tips to share?

“It can be super hard to travel and be sustainable at the same time. You don’t have the convenience of your own dishes etcetera when you’re on a plane or other transport. The first thing I’d recommend to people is the simplest one: get a reusable drink bottle. It doesn’t take much work and can make a huge impact.

I would also say, vote with your dollars. Not everyone has the money to make sustainable choices, but if you have the ability to do it, the market will respond. It’s kind of like the vegan and vegetarian options that are in our supermarkets now compared with 10 or 11 years ago. Because companies saw the demand, we now have a great range. I think the same thing is happening with genuinely eco-friendly alternatives. If we vote with our dollars and tell the companies what we want, we’re making a difference.”