Update: After concerns were raised about the die-off of fur seals, DOC officials acknowledged there were “significant environmental concerns for the Hauraki Gulf, particularly with dead seal pups washing up on beaches.” In communication with Friends of Hauraki Gulf chair Mike Lee, DOC Director of planning permissions and land operations Natasha Ryburn said this affirms the need to progress work to restore the health of these important marine areas. Shaun Lee continues to work with DOC to compile a record of dead seal sightings in the area.
Aucklanders stumbling across the bodies of baby seals washed up on beaches have raised questions about how fur seals are getting on in the Hauraki Gulf
When the first Polynesian explorers arrived in Aotearoa, only a handful of fellow mammals had beaten them to it. With an admission fee of being able to fly, swim, build a waka or catch a ride on one, this new land was shut off to all but a few species of mammal.
Among the bats, whales and dolphins was the New Zealand fur seal, or kekeno. Before the arrival of humans, they met in rookeries the length of the country to breed, hunt their fill of fish and squid and fill the air with cacophonous squawks.
Superficially closer to sea lions than the earless ‘true seals’ found in the rest of the world, there’s an inherent strange duality to these animals. While nimble and adroit hunters under the water’s surface, their waddling gait on land appears less than elegant.
But a bit of incoordination once they’d hauled out on the rocks must have posed little problem in the New Zealand of a thousand years ago. No terrestrial predators of a size to speak of meant these creatures were able to go about their business largely undisturbed for millennia.
Then humans showed up with clubs in hand and goose-bumped skin that might only be kept from the bitter cold of this new land by the fur of a seal.
Hunting by Māori reduced the range of the animals, and then sealing enterprise after the arrival of European colonists slashed their numbers apocalyptically.
At the peak of commercial sealing, the species’ population was down to a couple hundred breeding individuals – a devastating population bottleneck, down from tens of thousands before human interference.
Now defended by the Marine Mammals Protection Act, the New Zealand fur seal managed to do an about turn on the lip of the extinction precipice.
According to DoC, they are classified as not threatened, and with an increasing population.
“The last total population estimate was 200,000 approximately 20 years ago,” said DoC marine science adviser Laura Boren. “It will be higher now as the population has been increasing since their protection.”
The refugee populations of the southern islands have spread back up through the country – first up the coasts of the South Island, and now up to the northernmost discovered rookery in the Bay of Plenty.
It’s undoubtedly a success story for conservationists. But behind it hides the story of how much humanity is fumbling in the dark when it comes to our relationship with nature – whether it’s as we exploit and desecrate the natural world, or as try to put things right and safeguard the taonga that was here before us.
Lifelong conservationist and former Auckland councillor Mike Lee has lived on Waiheke Island since the 70s, and he’s never heard of so many dead baby seals washing up with the tide.
“Over the past 10 days we’ve had reports of up to 30 dead seals,” he said. “Even this morning there were five reports.”
Reports have come in Mangawhai in the north to the Coromandel – raising questions about conditions for the animals in the Hauraki Marine Park.
Although a spike in dead pup sightings may be a result of a thriving population of seals leading to more northward migration, a lack of baseline data from DoC leaves the true cause a mystery.
“Despite the national significance of the Hauraki Gulf Marine Park it’s a pretty bad state of affairs that more is known about the seals of the Ross Sea than the seals of the Hauraki Gulf,” Lee said. “What we do know is there are no rookeries in the area.”
This suggests these seal pups had a long way to go before they met their fate in the waters of the Gulf. During the winter months, seals have been known to migrate up to 100 miles away from their rookeries in search of food.
This, along with the range of habitats they inhabit during the summer, makes hard data on seals a precious commodity.
“More accurate population counts become difficult due to the range of terrain that the fur seals inhabit,” said DoC’s Boren.
“There is no single method that will work consistently across all colonies, and a blend of methods will be very costly and time consuming. Usually a particular pressure, such as tourism, earthquakes, or increasing overlap with human activities, leads to the prioritisation of a population assessment for a region.”
Despite the frequency of human activity in the Hauraki Gulf, the exact number of seals who frequent the area remains unknown.
Local conservationist Shaun Lee has been asking people to send him any sightings of dead seal pups so he can build a picture of how often it occurs.
“To my knowledge this is the first time they have been counted, the lack of previous records was one of the inspirations for the count,” he said.
He’s been surprised at how many reports have come in – with 30 confirmed and 24 unconfirmed as of Thursday afternoon.
Boren said an increase in the seal population may account for this, but a lack of population information makes it difficult to know if there is anything to worry about.
“The numbers of mortality we are seeing now may well still be within the realm of what we might expect within the Hauraki Gulf,” she said. “We currently have minimal baseline information on the population in the region, making it difficult to determine if this is normal or not.”
DoC’s next move is to look into each of the reported dead seal pups and assess their age and body condition, in order to get an idea of how and why these animals met their end.
“We are also working with colleagues at MPI to investigate any further mortalities and establish a plan for surveillance going forward,” Boren said.
The fact that people often only stumble across the carcasses some time after the animal has died makes it difficult to accurately determine the cause of death.
“Post-mortems are only possible on freshly dead specimens, so many of the dead seals reported will not be suitable for necropsy,” Boren said. “However, we can collect basic data from these specimens while keeping an eye out for suitable candidates for post-mortem.”
And situations where post-mortem analysis was an option have revealed some of the other factors that may be at play when it comes to seal health.
A fur seal pup was found in a still living but emaciated condition at Thorne Bay on the Devonport peninsula at the beginning of last month.
The pup was brought to Auckland Zoo for rescue, but was beyond saving despite intensive care from the veterinary team.
A necropsy found the seal was anaemic and suffering from a stomach parasite.
Mike Lee said it was hard to know exactly what was causing the seals to be unable to catch their own food, but believed there is a knowledge deficit around seals in the Gulf.
“They’ve suffered persecution from humans, and are starting to claw their way back – and now are they suffering a pandemic of their own?”
But according to Boren, there are many reasons people may be stumbling across the bodies of seal pups on their beach walks around this time of year.
Storm season coinciding with most pups’ first solo swims are met with more and more humans flocking to the seaside as winter comes to a close – all of which increases the chances of dead seal sightings, whether they are a pup or an adult.
Fur seals taking back their pre-human territories has also increased their chances of overlapping with human activity.
“As fur seals have been doing well recolonising much of their former range, DoC focuses interventions on either human induced situations,” Boren said. “For example – entanglements or acts of deliberate human interference or harassment.”
DoC advises anybody who comes across a seal should stay at least 20 metres away and try not to disturb them. In addition, people should keep dogs and children away from the animals, and don’t feed or attempt to touch them.
Meanwhile, reports of dead seal sightings and photographs can be sent to Shaun Lee through his blog.