GeoHazards cover story
Our article on the impacts of sea-level change was unexpectedly chosen as the cover story for the latest issue of GeoHazards, check it out here!
Relationship between sea-level change and loss of seaweed on a rocky shore
In this paper recent published in GeoHazards we evaluated the relationship between sea-level change and the severity of impacts in the major habitat-forming seaweed beds that sustain life on rocky shores. Check out the open access paper here: Threshold effects of relative sea-level change in intertidal ecosystems The 7.8 Mw Kaikōura earthquake affected a large section of the South Island’s east coast and led to a major re-assembly of ecological communities and coastal resource use. To understand the drivers of change and recovery in nearshore ecosystems, we quantified the variation in sea-level… Read More
Remote sensing coastal recovery using drones
Over the last summer our drone survey team was busy optimising methods for measuring change in the coastal environment change. We now have a comprehensive set of 3D models and imagery from 30+ field sites. Advantages of drone technologies include the ability to cover more ground and a greater range of habitats than we can manage in ground-based surveys alone, yet the resolution of these methods is impressive. Each model covers several hundred metres of coast and the size of each pixel is < 1 cm on the ground! We are using… Read More
Whitebait spawning sites in Kaikōura’s rivers
Early in 2019 we started work to fill a knowledge gap about whitebait in streams and rivers along the Kaikōura coast. For īnanga, which makes up the bulk of the whitebait catch, the spawning grounds are usually found close to the coast near the river mouths. Knowing where they are is useful for recovery planning in the same areas post-earthquake as well as for restoration projects in local waterways. Our survey programme started with fish trapping to find out which species were living in which rivers, after which we selected waterways that… Read More
Lab studies on seaweed recovery
Following on from Recover issue 4, Dan Crossett and Robyn Dunmore from the Cawthron Institute have had some interesting results from lab experiments set up to test the effects of temperature, turbidity and light on juvenile large brown seaweed growth and survival. We found distinct differences in species’ early life stage responses. Landsburgia quercifolia was more tolerantof a wider range of conditions, with similar growth and survival across treatments. In contrast, Durvillaea antarctica (rimurapa or bull kelp) was the least tolerant and was strongly affected by increases in temperature and turbidity, with… Read More
How much of the coast was uplifted by how much?
Although Covid19 set back some of our planned fieldwork, we put the lockdown period to good use to characterise some of the core earthquake impacts on the coast. One key questions is ‘how much of the coast was uplifted and by how much?’. Knowing this helps us to extrapolate the results from small-scale field surveys to the wider coast, which in turn is the best method for gauging the extent of impacts and how the recovery is looking overall. Being able to report the results as the ‘length of coastline’ affected is… Read More
Whitebait hatching experiment with Environment Canterbury
Our discovery of whitebait spawning sites in Kaikōura streams (see Recover Issue 3) ended with a twist in Waikoau / Lyell Creek when we realised that the eggs were unlikely to hatch. Thanks to Pete Adams at Environment Canterbury we came up with an engineering experiment in the form of a temporary closure — the reverse of mechanical stream openings that are routinely used to alleviate flood waters backing up after natural river mouth closures. In this case we temporarily blocked the mouth with gravel to raise the water level around 40… Read More
Beach birds: mapping hotspots for banded dotterels
Our beach birds study got underway this year on the uplifted Marlborough and Kaikōura coast beaches. In early December we completed a baseline survey of where Banded Dotterel nesting grounds are found, all the way from Oaro in the south to Marfells Beach in the north. That was a lot of walking for our team of three! The beach birds study aims to identify the most important nesting locations and assess interactions with human activities along the earthquake-affected coast. Knowledge of these sites fills a gap for coastal planning, especially where the… Read More
Overview of earthquake impacts
Initial Impacts Soon after the earthquake MERG began re-surveying our long-term research sites that span the coast. Many of these sites have been monitored for over 20 years. These surveys gave us a good understanding of the immediate impacts on coastal habitats and species. This work also provided a great foundation for our post-earthquake research. The following sections provide a snapshot of some important changes that resulted from the Kaikōura earthquake. Coastal fishes & invertebrates By chance, the earthquake happened to coincide with a high tide. This meant increased devastation to marine… Read More
What is RECOVER?
RECOVER is collecting data on recovery of the natural environment with a focus on the short to mid-term prospects for key species and habitats along the coast. We are particularly interested in understanding the nature of earthquake impacts, detecting barriers to a full recovery, and investigating how long it might take. Why?RECOVER is aimed at helping the coastal environment return to a ‘new-normal’ following the earthquakes. As we already know the earthquakes have caused massive changes, RECOVER focuses more on what happens next. Some main themes of the project include predicting the… Read More