Marine hotels: Invertebrate lodgings provide insights into Harbour’s health
Environment Canterbury media release: 11th December 2025
Deep below the surface of Whakaraupō Lyttelton Harbour are invertebrates offering important clues about the health of the harbour.
Earth and marine scientist Dr Joyce Yager knows this better than most. She’s keen to learn more about the invertebrates that call Whakaraupō home and share this information with the wider community. It’s an often-unseen aspect of the harbour.
Marine hotels offer insight into harbour life
Joyce has constructed multi-platform ‘marine hotels’, made from ceramic tiles, stainless steel and rope.
These have been suspended into the sea at different spots around the harbour and they’ve become great hang-out spots for a wide range of invertebrates.
Joyce and a small team of volunteers have taken charge of monitoring the hotels. They pull them out of the water regularly to see what invertebrates they’ve attracted and take learnings about the health of the harbour based on what hotel guests they find.
These findings help to create a deeper understanding of the overall health of Whakaraupō and its diverse ecology.
Appreciation for invertebrates in the harbour
Joyce said she wants the harbour to be safe for both sea creatures and humans for many years to come.
"We think about how we’re impacting sea birds and marine mammals a lot in Lyttelton, but maybe not so much the smaller organisms.
“What I hope is that people start thinking about animals they’ve probably never heard of in the harbour and how what we’re doing on land impacts some of these other marine animals.
“I really hope it’s a way for people to interact with marine life in the harbour that is lesser known and think about protecting not just the larger, air-breathing animals but also, some of the smaller animals,” said Dr Joyce.
What’s been found in the marine hotels
Invertebrates and other sea creatures found on the marine hotels have included:
- polychaete worms,
- bryozoans,
- tunicates/sea squirts,
- gastropods,
- bivalves,
- fish,
- decorator crabs, and
- lots of other types of crustaceans.
How the hotels are studied
Tiles are disassembled and placed in plastic trays with seawater. The top and bottom of the tiles are photographed, making note of what ‘floor’ of the hotel they are.
Using photographs and observation sheets, each floor side is examined for dominant species. The rough percentage of each tile covered, and the presence or absence of common organisms is noted.
From there, data can be processed for diversity metrics, including what proportion of the population of the hotels is native, endemic, introduced or invasive.
Data is collected over time, including if sea creature communities in marine hotels change seasonally, what happens if the water heats up suddenly, if the same organisms dominate at each hotel site, and if the same organisms dominate all year long.
For individual organisms, photos are taken and uploaded to iNaturalist so that the observations can be viewed in publicly available datasets.
Sometimes this leads to the discovery of new animals that haven’t been observed in the harbour before.
Getting local students involved
Local schools have been encouraged to adopt their own marine hotels as part of wider learning and curriculum integration.
Students from Governors Bay school did an inquiry on conservation and habitats with a ki uta ki tai (mountains to the sea) overview of te taiao (the environment). Pupils explored local places, including Living Springs, learnt about restoration projects taking place, and carried out water quality sampling and coastal and foreshore monitoring.
During these field trips, students and whānau made several connections on how land use and current and historical practices have affected the harbour.
Schools are involved in the marine hotel initiative through the Enviroschools kaupapa.
Support and funding for marine hotels
Joyce’s marine hotel initiative is supported by Whaka-Ora Healthy Harbour - a partnership programme helping to ensure that the ecological and cultural health of Whakaraupō is protected.
Programme partners include ECan, Te Hapū o Ngāti Wheke, Te Rūnanga o Ngāi Tahu, Christchurch City Council, and the Lyttelton Port Company.
The marine hotel initiative is also supported by Christchurch City Council’s Community Waterways Partnership Fund and generous donations from members of the community.
Joyce would love to see more volunteers take charge of looking after and checking marine hotels around the harbour.
She hopes the marine hotel initiative will encourage people to think more about protecting even the smallest animals in Whakaraupō.
Adopt a marine hotel in Whakaraupō Lyttelton Harbour
Contact Joyce to adopt a marine hotel:
- on the Joyce Yager website, or
- by email (joyce@invertebrates.earth with the Subject: I want to get involved with the marine hotel initiative).
Learn more about the Whaka Ora Healthy Harbour programme.
Find out more about the Christchurch City Council Community Waterways Partnership Fund.