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
Young pāua growing well
Our work monitoring the juvenile pāua around Kaikōura has shown encouraging signs of recovery of this hardhit population. Wild pāua tagged a year ago have had excellent growth rates and survival. They’re quickly advancing through the size classes and will soon migrate to deeper waters and join the adult spawning groups, a key step in recovery. The abundance of pāua at our sites is increasing significantly through time, and we are seeing much higher numbers than we did in theearly days after the earthquake. Hatchery-raised reseed pāua planted in 2018 by the… Read More
Kelp and seaweed recovery
In the summer of 2019 NIWA and the University of Canterbury completed aerial drone surveys of many sites along the Kaikōura coast to examine the survival of vulnerable kelp species such as bull kelp (Durvillaea spp). This included testing the relative accuracy of readily available “RGB” cameras, and enhanced spectral cameras (multispectral cameras). This research revealed that both RGB and multispectral cameras can be used effectively for mapping broad scale distribution of marine vegetation (i.e., kelp), but multispectral cameras can be used to examine species biodiversity at higher taxonomic resolution. NIWA and… 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
Paua population monitoring
Monitoring of intertidal paua populations along the Kaikōura coastline has yielded some interesting findings. It looks like overall the hot summer hasn’t adversely affected the vulnerable juveniles, who seem to be growing more quickly than we expected. Recaptured seed paua, identified by the blue shell material at their apex from hatchery diet, have shown phenomenal growth rates since being seeded a year ago. Paua that grow quickly will reach predator release sooner, the size at which they are less likely to be eaten. The natural population is now dominated by larger paua… Read More
Juvenile paua research
We have had a busy past few months doing some experimental fieldwork. This included a pilot study looking at some semi-artificial reef installations to see if juvenile paua would use some rock-filled cages for cover/shelter. These were designed to provide optimal habitat for wild paua, and possibly to use as deployment structures for paua reseeding efforts. In just a couple weeks we found that all sorts of animals had voluntarily crawled into the cages, including plenty of black and yellow paua aged 1-2 years. We were pretty excited at this response, which… Read More
