Ambergris washes up worldwide,
including in East Africa, India,
Australia, New Zealand, the
Bahamas, parts of northern
Europe, the east coast of the
US and the south coast of Chile.
But before you go beachcombing,
check local laws as some countries
prohibit the export, sale or even
possession of ambergris.
After that, it is down to luck
and scouring the shoreline or, if
you are so inclined, training a dog
to help sniff it out. Ambergris is
rare – produced in the gut of only
a few sperm whales – and easy to
confuse with more common items
of jetsam, such as congealed
cooking oil. It is lumpy and uneven
in shape, feels waxy and hard,
but can be scratched. Its colour
and smell (and value) vary by how
long it has been at sea. The least
valuable kind is black and foul
smelling. White ambergris (the
most valuable) and brown are
older. They have a sweet aroma
with musky, earthy and marine
notes, plus hints of forest floor.
There are ways to test a find,
but this is better left to experts.
Last year, a woman who tested
a possible piece of ambergris by
poking it with a hot needle, ended
up with a fireball in her kitchen.
Firefighters told her the lump was
probably an unexploded grenade
from the second world war.
In search of
floating gold
Claire Ainsworth is having
a whale of a timeBut ambergris doesn’t just contain
DNA from sperm whales. Macleod and his
colleagues found patchy sequences from a
multitude of other organisms, too, ranging
from bacteria and other microbes to intestinal
worms and armhook squid, the whales’ usual
prey. Exploring the microbial sequences in
more detail could allow researchers to get a
handle on the gut microbiomes of past sperm
whale populations, which in turn could reveal
how the pressure of whaling affected their
foraging strategies and microbiome diversity,
says Macleod. Sequences from the worms
and squid could reveal knock-on effects on
prey animals. “It shows the kind of ecological
ripples resulting from killing lots and lots
of whales on all these other species,” he says.
Studying whale digestion and the role
of their gut microbiomes can even help us
understand our planet’s biogeochemistry
and climate. “Whales are consuming a large
amount of carbon every day,” says Amy Apprill
at Woods Hole Oceanographic Institution
in Massachusetts. She and her colleagues
have been working with Indigenous Alaskan
subsistence hunters to see how microbes
in the guts of bowhead whales influence the
digestion of wax esters, a carbon-rich chemical
found in species the whales eat. Others have
shown that whale excrement creates plumes
of nutrients, such as nitrogen, in the water
column, nurturing the growth of plankton
that consume carbon as they photosynthesise.
As well as storing carbon in their bodies while
living, whales often take it with them in death,
sinking to the deep ocean where their carbon
can remain in sediments for centuries.
Understanding more about whale gut
microbiomes will also help scientists keep
track of how modern populations are coping
with climate change and other stresses.
“The microbiome might be a really useful
metric for health in these animals,” says
Apprill. Ambergris would provide “an amazing
baseline” to better understand and add context
to data from today’s animals, she adds.
Sadly, we are unlikely to see a return of
the pristine oceans of the pre-whaling era.
But ambergris could help us understand how
these charismatic beasts might survive a future
in the noisy, warming world we have created.
For that reason, at least, it would be priceless. ❚18/25 December 2021 | New Scientist | 57