Seals ‘remarkably resilient’ in coping with quake
It was once one of the most popular attractions on the Kaiko¯ ura coastline – an idyllic river pool beneath a waterfall, filled with seal pups at play. That changed on November 14, last year.
When the earthquake struck, the cliff above the pool came crashing down, while tonnes of rock and earth fell from O¯ hau Point onto the coast which a large seal colony called home.
It seemed the colony was gone, but one year on, the seals have proved ‘‘remarkably resilient’’ – though dozens have been killed in the efforts to rebuild the crucial road and rail which hugs the coastline.
About 180 bull seals have settled along the coast around O¯ hau Point, boding well for the breeding season about to begin. Formerly about 2000 seal pups were born at the site each year.
Department of Conservation (DOC) ranger Mike Morrissey, who has worked with the seals over 30 years, was one of the first at the waterfall pool after the quake. He said it was ‘‘no longer a pool, it’s just a mound of rock’’.
Northern South Island operations manager Roy Grose said further rock falls from the cliff beside the waterfall pool were possible. The area would remain closed to public access.
The waterfall pool and track leading to it are on privatelyowned land. Grose says DOC had been in discussion with the land owners but no decision on the pool’s future had been made yet.
He said seals were still being seen in large numbers around the O¯ hau Point area, though many had moved to a new territory slightly to the north.
The Kaiko¯ ura seal population seemed ‘‘remarkably resilient to the impacts of the earthquake’’ and subsequent work on the road and railway line that butted up against their habitat, said Grose.
Dozens of seals have died because of the highway rebuild following last November’s earthquake, despite the best efforts of the workers.
In the last three months, the North Canterbury Transport Infrastructure Recovery alliance (NCTIR), who are rebuilding the battered transport corridor, have recorded 41 seal deaths caused by earthworks or road rebuild activities.
A total of 294 dead seals have been found by rebuild workers over the same time period, but the cause of the remaining 253 deaths is unknown – but not thought to be related to the works.
It is common for young seals to die in the late winter and spring.
NCTIR environmental manager Manea Sweeney said they were doing ‘‘everything they can’’ to minimise seal deaths throughout the project.
More than 11,000 seals (many repeat offenders) have been moved by seal handlers who are constantly monitoring the coastline outside the ongoing roadworks.
In places, a row of 5-tonne seawall blocks have been temporarily laid on the edge of access roads to keep the rare mammals outside the work zone.
She said moving seals involved ‘‘a huge amount of work’’. Teams of seal handlers were working 24 hours a day to match the schedule of the road works.
Sweeney said NCTIR had a ‘‘robust’’ environmental management framework which helped the construction crews with how they should go about their work. The environmental team was made up of about 40 people.
‘‘With the sheer scale of it, this could be the largest environmental team on a construction project ever in New Zealand.’’
Grose said DOC was very pleased with the ‘‘care and considerable effort’’ those rebuilding the road had shown in keeping the seals safe.
The New Zealand fur seal, or kekeno, is fully protected by the Marine Mammals Protection Act. Those rebuilding the road were given permission to kill or injure seals as part of their work until March 2018, as legal protection for any incidents which saw seals accidentally killed during the works.
In May, 30-40 seal pups were found dead in one area just south of O¯ hau Point. Autopsies done at the time suggested their deaths were because of pneumonia. There have been no reports of similar group deaths since.