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.

Coastal tectonics and habitat squeeze

We're pleased to announce publication of a new paper in the international journal Natural Hazards.
This is the first chapter in the 'Resilient Shorelines' Ph.D. 

Coastal tectonics and habitat squeeze: Response of a tidal lagoon to co-seismic sea-level change

dx.doi.org/10.1007/s11069-020-04147-w

The Canterbury earthquakes provided a rare opportunity to observe the actual effects of a sea-level rise event. This study explores the impacts of hydrological changes resulting from tectonic ground movement in low-lying coastal environments, and draws analogies with future climate change.

The paper describes landscape-scale changes and assess interactions with human land-use patterns and disaster recovery responses that include a large scale managed retreat. The results illustrate mechanisms by which 'coastal squeeze' effects may occur with sea-level rise - and also ways to avoid them through innovative planning and design.  

Principles identifiable from the actual impacts in this case provide useful insights for other situations of sea-level rise.

We highlight the need for an improved focus on whole-system resilience in responding to sea-level changes, and the importance of disaster recovery processes for adaptation to climate change.

See also a companion paper that evaluates impacts on coastal vegetation and consequences for conserving important ecosystems over time.

Using artificial habitats as a natural habitat detection tool

We have a new paper published in the journal Ecological Indicators that describes the science behind using artificial habitats (such as straw bales) to as a detection tool.

We used this approach to help identify īnanga spawning habitat in degraded waterways where egg mortality can make it difficult to find the eggs directly.

Read more here

New report on earthquake effects

The Waterways Centre for Freshwater Research and the Marine Ecology Research Group are pleased to provide a new report on the distribution of īnanga spawning sites in Ōtautahi Christchurch. Thanks to the Engineering New Zealand / Water NZ Rivers Group for supporting this work.

Highlights include comprehensive information on changes in relation to the Canterbury earthquakes, and a summary of the key implications for waterways management.

Read more here

Collaboration with NIWA to develop salinity models

The Resilient Shorelines team would like to thank the Brian Mason Scientific & Technical Trust and also NIWA for bringing their support to this exciting research.

An interesting though unexpected finding of this work was the discovery of a leak in the Woolston Tidal Barrage. The model calibration was excellent in the lower estuary and in the Avon / Ōtākaro. However there was a strong  anomaly between the modelled versus observed salinity datasets for the Heathcote / Ōpāwaho that have been influenced by the tidal barrage leakage. Read more about it here in the Brian Mason Trust report on 'Development of a fine-scale salinity model for the Avon Heathcote Estuary Ihutai'.

Read more here

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