The resilience of crayfish in Tauranga Harbour

PhD student Kiamaia Ellis describes crayfish as a vulnerable taonga species. Local iwi in Tauranga believe the crayfish population is decreasing because of urban, industrial and harvesting pressures. But Kiamaia is keen to be a part of the solution, so she's studying the resilience of pēpi kōura / baby crayfish. She wants to understand how these tiny species that take eight years to become an adult are able to thrive based on a kaitiakitanga or guardianship approach.

Inside the lab space at the Coastal Marine Field station Kiamaia Ellis checks in on the pēpi kōura, one is not much more than two centimetres in length.

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In another tank one is darker in shell colour and the other is more translucent, Ellis says it's because of how much light the kōura expose themselves to while in their tanks.

One pēpi is shy and only comes out when it's feeding time, the observation notes refer to it as the 'pipe cray'.

"I'm actually quite attached to the pēpi kōura...they're such characters there's one there that comes out and dances around and plays and we have a little kōrero" Ellis says.

Ellis' Phd research project 'Pēpi Kōura: A transdisciplinary mātauranga Māori and science approach to enhancement and resilience of puerulus kōura in a changing climate" stems from the aspirations of local tangata whenua who according to Ellis have 'observed the degradation of tāonga species over many generations'. Local iwi put this down to urban, industrial and harvesting pressures.

Te Kehu Butler has witnessed first-hand the impact commercial fishing has had at Mōtiti Island located sixteen kilometres north east of Tauranga. According to Butler the once abundant crayfish pataka kai (food resource) areas have all but disappeared. Butler is a seafood diver and argues that commercial fishing was another problem.

"Commercial fishermen would get a license and they would bombard the whole island...and they'd take all the crayfish it made It harder for us to feed the manuhiri at the marae at different occasions...so when they bombed the island like that the old people used to have to go out deeper to dive for crayfish" he says.

In 2013 Ellis spent some time interviewing her Kaumatua to understand the stories and customary knowledge about pataka kai. She's also drawing on the maramataka (Māori lunar calendar) to correlate the times of recruiting kōura from the harbour…

Go to this episode on rnz.co.nz for more details