Risk factors for coastal conservation revealed by the Canterbury earthquakes

We're pleased to announce publication of the companion paper to ‘Coastal tectonics and habitat squeeze’ in the international journal Science of the Total Environment.

Risk factors for the conservation of saltmarsh vegetation and blue carbon revealed by earthquake-induced sea-level rise

dx.doi.org/10.1016/j.scitotenv.2020.141241

This paper investigates the resilience of coastal vegetation to the effects of relative sea-level change which is the subject of very few empirical studies due to the scarcity of sea-level change events of appreciable magnitude in modern times. The novel opportunity provided by the Canterbury earthquakes allowed us to design a robust impact assessment to quantify effects and identify anthropogenic factors that influenced the pattern of losses or gains. 

The findings illustrate opportunities for managing risks to coastal vegetation types such as saltmarsh which are threatened by sea-level rise. 

The conservation of these characteristic ecosystems is of global importance for the sequestration and storage of blue carbon alongside many other ecosystem services that include considerable habitat values for characteristic wildlife such as waders and shorebirds in the Christchurch case.

In summarising results from the study we derived four key principles for building the resilience of coastal ecosystems that will be of interest to coastal managers worldwide.

New methods paper - Census survey approach for īnanga spawning habitat

Waterways and MERG have recently published details of a survey methodology for locating and mapping īnanga spawning sites near coastal rivermouths. 

Read more here.

Spawning habitat maps for Ōtautahi waterways

These maps show results from two years of spawning site surveys plus two years of straw bale experiments in the waterways of Ōtautahi Christchurch. Compare them with the Whaka Inaka maps where we took all of the known sites at the end of 2015 and tested if there might be others both in the gaps and further upstream/downstream. And yes there were.

These maps are available as free downloads. There's some other maps available too ..
check them out here www.resilientshorelines.nz/p/resources.html

Resilience research on whitebait featured in UC Chronicle

The September 2016 issue of the Chronicle He Kupu Whakamahara ran a story on our research into the resilience of whitebait spawning sites in Ōtautahi Christchurch following the earthquakes.

Follow the link here to the article online

Some recent publications relating to this work:

• Earthquake effects on spawning sites - download the original report here
• Identifying īnanga spawning sites in plans - short report available here
• Census survey approach to quantifying īnanga spawning habitat New Zealand Journal of Marine and Freshwater Research, 52(2), 284-294.
• Earthquake-induced habitat migration Aquatic Conservation: Marine and Freshwater Ecosystems, 2018; 1-11.

Comparative study of coastal hydrosystems

Over the 2016 summer we are surveying eight coastal hydrosystems for a comparative study. Four study sites are in Canterbury and four on the West Coast. The study sites have been chosen to represent a range of different rivermouth and estuarine environments and a wide range of data are being collected to characterise each site in ecosystem terms. Look out for more news from these surveys in the coming months.

Earthquakes cause a shift in the location of īnanga spawning sites

One of the main objectives for our whitebait conservation study was to determine if the earthquakes had altered the location of spawning sites for īnanga (Galaxias maculatus) for spawning. They are typically found in specific locations near the freshwater-saltwater interface at rivermouths. As such, īnanga spawning sites are potentially a very good indicator of change. Conversely, they may be especially vulnerable to changes that affect the availability or condition of suitable habitat.

And the answer is - yes, there has been a major shift in the location of spawning compared to all previous records!

Read more here

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