We know that global temperatures are on the rise, and even if we could stop all greenhouse gas emissions tomorrow some impacts would still be locked in. 2021 was New Zealand's warmest year on record. Could it also have been the coldest year of the rest of our lives?
Dr. Rebecca Gladstone-Gallagher at Ōmokoroa estuary Photo: RNZ / Claire Concannon
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In the week that the IPCC has checked our homework and found that global efforts to reduce emissions are coming up short, we need to prepare for a future that includes warmer temperatures, sea level rise and increased extreme weather events. This week’s episode includes two stories of researchers doing just that.
The extreme life of a cockle
Estuary intertidal regions are interesting environments uniquely impacted by warming of both the air and the sea. During daytime low tides uncovered sediment is heated by the sun. Incoming shallow water flowing over this hot sand or mud gets warmed to bathwater temperatures.
Therefore, combinations of land and ocean heatwaves, coupled with low tides in the middle of the day when the sun is at its hottest, lead to extreme temperature events in these environments. These are exactly what University of Auckland researcher Dr. Rebecca Gladstone-Gallagher wants to capture.
Rebecca is leading a project to deploy a network of temperature sensors, or loggers, in 25 locations across New Zealand’s estuaries. Long term temperature loggers will remain out for a year, capturing the general trend over 20-minute intervals. But to get details on these extreme temperature events, Rebecca is also deploying loggers that will take readings every two minutes.
For these deployments she has chosen hot weeks with low tides in the middle of the day. The loggers will be placed just above and within the sediment, in cockle bed areas, so that Rebecca can get an idea of exactly what the animals are experiencing.
Claire Concannon joins Rebecca and her collaborator Professor Conrad Pilditch of the University of Waikato to learn more about the cockles that live in these estuaries, and how Rebecca hopes that this monitoring will help them.
Professor Conrad Pilditch and Dr. Rebecca Gladstone-Gallagher Photo: RNZ / Claire Concannon
Rebecca’s work is funded by a 2020 Marsden fund.
Coastal marae and sea level rise
Sea level rise and increased coastal flooding will also be a part of our climate change future, threatening infrastructure built close to the coast. Starting as a summer student with the Resilience to Natures Challenges National Science Challenge Akuhata Bailey-Winiata wanted to understand what this meant for marae across Aotearoa.
From the Māori Maps database assembled by Te Potiki National Trust Akuhata identified those marae near the coast or estuaries that could be at risk. His work continued on into a masters in which he used a NIWA dataset to look at the potential exposure to 1 in 100 storm events that could cause flooding at these marae.
Now Akuhata has begun his PhD - having investigated the problem and the exposure of these marae he now wants to work with hapū and iwi to investigate potential solutions.
Akuhata Bailey-Winiata Photo: RNZ / Claire Concannon
Akuhata’s research is supported by the Resilience to Natures Challenge National Science Challenge, the University of Waikato, the University of Auckland, NIWA and the New Zealand Coastal Society. His work has made use of the marae dataset from Te Potiki national trust.
To learn more:
- Listen to a previous episode where Conrad speaks to Alison Ballance about estuary ‘tipping points’
- This episode discusses the consequences of sea level rise for low-lying parts of New Zealand.
