Marine hotels provide insights into Lyttelton Harbour health

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 and is keen to learn more about the invertebrates that call Whakaraupō home and share this information with the wider community.

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.

She 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.

Dr Yager 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 Yager.

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.

Local schools have also 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.

Schools are involved in the marine hotel initiative through the Enviroschools kaupapa.

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 us, 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.