Translator: Maria Beatriz Reviewer: Elena Montrasio
Tena koutou, tena koutou, tena koutou, katoa.
Greetings to you all.
I never thought I'd look a humpback whale in the eye.
Most geologists don't.
But that all changed ten years ago, when my dear friend, Nan Hauser,
director of Cook Islands Whale Research,
introduced me to this beautiful creature.
Now you too are looking into the eye
of one of the endangered humpback whales
that seasonally resides in the waters off Rarotonga.
When I look into that eye, I’m amazed by what I see.
Calm, confident, curious,
studying me just as much as I'm studying it.
It's that confident curiosity that draws me to whales.
But, it's also our history.
The human-whale relationship is, of course, a strained relationship.
We’ve not always treated whales, or their environment, humanely.
So that's why I’m here, a geologist who studies whales,
doing what I can to pay back a debt,
doing what I can to save whales with science.
Now I’m sure many of you are wondering,
"Why do whales need saving? I thought there was a ban on whaling."
Indeed, 2016 marks the 30th anniversary
of the International Whaling Commision's moratorium on commercial whaling.
But unfortunately, not all populations have recovered.
The southwest pacific humpback whales provide an important example.
At present, there are only 3,000 to 5,000 humpback whales
that seasonally reside in the waters of Oceania,
roughly 10% of the pre-whaling population.
Let’s take a closer look at a few of those whales.
What you’re looking at here, in this absolutely stunning footage,
shot by Nan Hauser and her team,
captures an endangered humpback whale mother
and its week-old calf, playing in the waters off Raro.
I think she's giving him some backscratch.
Such intimate behaviors are all but impossible to record from a ship.
Non-invasive techniques such as drone photography
are important new tools in our quest to save whales with science.
The footage also reinforces a key point: humpback whales deserve saving.
These are smart, beautiful, and caring creatures.
So the question really becomes, "How do we save whales with science?"
Well, when you consider the fact that the major threats to whales today
include entanglement in fishing lines, ship strikes,
marine development, pollution,
it seems the answer is relatively straightforward.
We can use science to predict when and where whales will be located,
and then modify where we fish, shift our shipping lanes,
revise our at-sea behavior,
such that adverse human-whale interactions are minimized.
So saving whales with science really starts with understanding
how whales navigate.
We need to understand their movements,
and to do that, we can use satellites to track them.
What you're looking at here are four satellite tracks of humpback whales,
tagged off Rarotonga in 2007 and in 2014.
And this plot just blows me away every time I look at it,
for many reasons.
First, those are remarkably straight lines.
Humpback whales can follow constant courses across the ocean,
and last time I checked, the ocean’s moving!
That means that these whales are compensating for drift.
Second key point: humpback whales commute between islands,
just as Pikaia, the ancestor to many New Zealand Māori, once did.
Our satellite tracking is reinforcing what Māori
and other Polynesian cultures have known for centuries:
humpback whales actively target and seek out certain islands
at certain times.
Third point: those tracks are on top of each other.
Despite migrating at distinctly different times,
humpback whales can find and follow the same migration routes.
In biology we call this "route fidelity,"
and prior to our satellite tracking,
it had been unrecognized in humpback whales.
Ultimately, you know, in 2007,
when we saw the first whale do this movement,
we thought it was a fluke! Pun definitely intended.
(Laughter)
When we saw three more whales do it in 2014,
we knew we were on to something.
So what you're looking at here is the next big breakthrough that happened.
Not only can humpback whales find and follow the same paths,
but there's a temporal pacing to these movements.
What you’re looking at in the map is three humpback whales
tagged off the coast of Brazil.
There are three whales there,
three whales following an identical 4,000-km-long migration route,
despite migrating 15 days apart.
It was the temporal cycling that led me to hypothesize
that perhaps humpback whales were navigating using gravity.
Now the idea that animals use gravity for navigational purposes
dates back to the 1970s, with the work of Larkin and Keeton.
It was then developed by Kanevski in the 1980s,
and just in the past year, an absolutely radical paper just came out,
showing that deliberate movements of plant leaves
can be correlated with the tidal gravity cycle
of the International Space Station.
Really cool research.
So, back to whales, when we replace latitude and longitude with gravity,
you get the plot on the right.
So, this plot on the right is showing you the spatial components of gravity
on the vertical axis,
and some temporal components of gravity on the horizontal axis.
The vertical axis specifically is showing you
the latitude-dependent, and the bedrock-dependent gravity;
the horizontal axis is showing you what’s called the tidal gravity,
here represented by the moon illumination cycle.
The key thing I want you to see in this plot, is the geometric pattern.
There's a systematic, reproducible, and thus predictable, pattern
in these data.
In fact, they're symmetrical.
When you reverse the axes, the tracks plot on top of each other.
It's like a double helix,
you flip it back over the other way, you get the same result.
It’s this symmetry that leads me to believe
that humpback whales navigate using gravity.
Not convinced? Let’s have another look at those Rarotonga tracks.
When we replace latitude and longitude
with the spatial and temporal components of gravity,
what we see is a very similar, systematic, reproducible,
and highly symmetrical pattern.
I don’t think predictive models are that far off.
I think we’re getting very, very close to developing these predictive models.
In fact, Nan and I are already using this information
to assist marine developers.
The data you’re looking at here is being used to inform
a decision-making process regarding a proposal
to lower a deep sea cable connecting Samoa to Rarotonga.
What these tracks allow us to say to the developers is,
“Fantastic, put that fiber line cable down at the bottom of the ocean,
but please just don’t do it during these months,
when we know humpback whales are migrating through the area.”
So in this way, our research is already helping save whales with science.
A second way we can save whales with science
is by seeing them more clearly.
We can work to minimize ship strikes
through the creation of automated detection systems,
basically an early warning system of sorts
where you can alert a ship's captain
to whales in the vicinity of his or her vessel.
Such automated detection systems would be absolutely invaluable tools
for biologists studying whales in the remote islands of Oceania.
So, what might an automated detection system look like?
How might these systems work?
Well, thermal imaging is the key.
Just a month and a half ago, in Rarotonga,
a U.S. study abroad student
from the Frontiers Abroad program and I went up to Roro
to answer the question:
"Do humpback whales appear as thermal anomalies,
with respect to relatively warm tropical water?"
And as the movie up there is showing you,
the answer is inequivocably “yes.”
The question now becomes,
"At what distance do humpback whales no longer appear as thermal anomalies?
And the answer to that question is crucially relevant
to determining the contexts in which automated detection systems
using thermal imaging can be successfully deployed.
So, many whale populations have been recovering
since the IWC enacted its moratorium on commercial whaling,
but some populations, such as the humpback whales of Oceania,
remain endangered.
I believe we are obligated to protect these whales from further harm.
I believe we can do this.
We can do this by understanding how whales navigate,
and we can do this by seeing whales more clearly.
So when that whale looks you in the eye,
don't be fooled by its confident curiosity.
Whether it knows it or not, that whale is vulnerable.
Only we can help to keep it safe,
and only we can save whales with science.
Waitaki mata.
Thank you.
(Applause)