An etching from 1577 shows three beached Sperm Whales,
highlighting the long history of whales beaching themselves
Early in the morning of Friday February 9,
2017, a group arrived at the isolated Farewell Spit on
the coast of New Zealand. Traveling to capture one of
the world's most beautiful coastlines at sunrise, the
team, including a photographer and a writer from
This NZ Life, discovered the devastating sight of
over 400 beached pilot whales.
New Zealand's Department of Conservation had
spotted the large pod moving towards the coast
overnight, but by the time anyone arrived on site Friday
morning over 300 of the whales were already dead. The
community sprung into action and over 500 volunteers
turned out to assist with the rescue effort, but the
drama wasn't over.
On Saturday afternoon a second pod of over
200 pilot whales hit the shore, turning this into the
second largest mass stranding of whales in New Zealand's
history. Volunteers left the site Saturday night
dreading the scene they would face come Sunday morning.
But in a remarkable reversal of fortune, all but 17 of
the newly stranded whales had managed to self-rescue
with the tide by the next day.
The tragic mass stranding of these majestic
creatures in New Zealand has rekindled debate as to the
mystery behind what causes mass cetacean beachings. From
a new study into the effect of solar storms on the
navigational abilities of whales to the potential damage
that our military sonar systems cause, there are
numerous theories looking to explain this long-standing
conundrum.
Solar Storms
Just a few days before the historic mass
whale stranding in New Zealand, NASA heliophysicist
Antti Pulkkinen
announced a new study was being launched to
investigate whether solar storms could be a major factor
behind these baffling natural tragedies. Pulkkinen
suspects that magnetic anomalies caused by coronal mass
ejections from the Sun could have a disorienting effect
on animals that rely on magnetic-field sensing for
navigation.
Pulkkinen, an expert with a comprehensive
understanding of how space weather affects our planet,
will undertake a rigorous data-mining operation
analyzing NASA's space weather databases and animal
stranding data gathered by the federal Bureau of Ocean
Energy Management and the International Fund for Animal
Welfare.
"What we're going to do is throw cold, hard
data at this," explains Pulkkinen. "It's a long-standing
mystery and it's important that we figure out what's
going on."
The human influence
Environmental groups have long argued that
noise pollution in the ocean, in particular the
military's use of sonar, has been responsible for a
number of whale stranding incidents. After numerous
beaching incidents that correlated with significant
military sonar exercises, the US Navy
did conclude in late 2001 that a small number of
stranding incidents were related to the use of sonar.
Over the following decade, several court
battles resulted in a moderate amount of regulation
surrounding how and where the military could conduct
sonar exercises. Most recently,
a 2015 settlement between the US Navy and the
National Marine Fisheries Service agreed that certain
marine areas be protected from training exercises that
would result in significant undersea noise pollution.
While the connection between some stranding
incidents and human influence has been comfortably
proven, this still only accounts for a small amount of
specific, and often small, beachings. The explanation
behind the larger-scale mass strandings that have been
reported for hundreds of years still proves more of a
mystery.
Nature's whale-traps
After it was identified that there were
numerous spots in the world where mass whale beachings
seemed to continually reoccur, several studies began to
hypothesize a link between the topography of the coast
and these stranding locations. A team at the University
of Western Australia
concluded that a gently sloping beach can present a
major problem for echo-navigation systems in cetaceans.
The team studied the topography of Ocean
Beach in Tasmania, a known hot-spot for recurring
cetacean beachings, and discovered the ocean slope to be
nearly flat, but not quite. They found the slope to be
an almost imperceptible half of one degree, resulting in
a depth change of 20 meters (66 ft) over three
kilometers (1.9 mi) leading to the shore.
This type of gentle-sloping in a coastline
was suspected to be a major factor in causing pods of
whales to unwittingly end up in unexpectedly shallow
waters. The animal's echo-location processes tend to be
unable to pick up this subtle gradient, resulting in
them straying into waters that are difficult to
navigate.
Many recurring mass stranding locations,
including Farewell Spit in New Zealand, have been found
to exhibit this topographical gentle-slope, leading to
researchers dubbing certain geographical spots on the
globe as "whale-traps."
A complex combination
We may be getting closer to understanding
why the phenomenon of cetacean beaching occurs in some
specific instances, but it is becoming clearer that
there isn't one singular answer to this long-standing
mystery. Some researchers insist social factors are
important in explaining why mass beachings occur. Many
species of whales exhibit incredibly social tendencies
and when a member of their pod becomes trapped or in
peril their cries for help could draw more to the
coastline.
Other stranding incidents are thought to be
a result of changing feeding patterns. A series of
sperm whale strandings in recent years was suspected
as related to starvation, with the animals straying into
unfamiliar shallow water in search of food.
Be it solar flares, odd coastal topography,
human-influenced undersea noise pollution, or a variety
of social factors, the complexity of this phenomenon
means that, unfortunately, it's likely to continue for
many years to come. As scientists gain a greater
understanding of the factors that trigger these
devastating events, hopefully we will be able to predict
them in advance, and therefore be better prepared to
help, or even find a way to prevent them altogether.