The weird wonderful world of bioluminescence Edith Widder
so I want to take you on a trip to an
alien world and it’s not a trip that
requires light-years of travel but it’s
to a place where it’s defined by light
so it’s a little appreciated fact that
most of the animals in our ocean make
life I’ve spent most of my career
studying this phenomenon called
bioluminescence I study it because I
think understanding it is critical to
understanding life in the ocean where
most bioluminescence occurs I also use
it as a tool for visualizing and
tracking pollution but mostly I’m
entranced by it since my first dive in a
deep diving submersible when I went down
and turned out the lights and saw the
fireworks displays I’ve been a
bioluminescence junky but I would come
back from those dives and try to share
the experience with words and they were
totally inadequate to the task I needed
some way to share the experience
directly and the first time I figured
out that way was in this little single
person submersible called deep Rover
this next video clip you’re going to see
how we stimulated the bioluminescence
and the first thing you’re going to see
is a transect screen that is about a
meter across in front of the Sun a mesh
screen will come into contact with the
soft bodied creatures of the deep sea
with the subs light switched off it is
possible to see their bioluminescence
the light produced when they collide
with the mesh
this is the first time that has ever
been recorded
so I recorded that with an intensified
video camera that has about the
sensitivity of the fully dark-adapted
human eye which means that really is
what you would see if you took a dive in
a submersible but just to try to prove
that fact to you I brought along some
bioluminescent plankton in what is
undoubtedly a foolhardy attempt at a
live demonstration so if we get up the
lights down and have it as dark in here
as possible I have a flask that has
bioluminescent plankton in it and you’ll
note there’s no light coming from them
right now either because they’re dead or
because I need to stir them up in some
way for you to be able to see what
bioluminescence really looks like Oh
I spend most of my time working in the
dark I’m used to that okay so that light
was made by a bioluminescent
dinoflagellate a single-celled alga so
why would a single-celled alga need to
be able to produce light
well uses it to defend itself from its
predators the flash is like a scream for
help it’s what’s known as a
bioluminescent burglar alarm and just
like the alarm on your car or your house
it’s meant to cast unwanted attention
onto the intruder
thereby either leading to his capture or
scaring him away it’s a lot of animals
that use this trick for example this
black dragon fish it’s got a light organ
under its eye it’s got a chin barbel
it’s got a lot of other light organs you
can’t see but you’ll see them here in a
minute so we’d have to chase this and
the submersible for quite some time
because the top speed of this fish is
one not which was a top speed of the
submersible but it was worth it because
we caught in a symmetric capture device
brought it up into the lab on the ship
and then everything on this fish lights
up it’s unbelievable the light organs
under the eyes are flashing that chin
barbel is flashing it’s got light organs
on its belly that are flashing fin
lights it’s a scream for help it’s meant
to attract attention it’s phenomenal and
you normally don’t get to see this
because we’ve exhausted the luminescence
when we bring them up in nets there’s
other ways you can defend yourself with
light for example this shrimp releases
its bioluminescent chemicals into the
water just the way a squid or an octopus
would release an ink cloud this blinds
or distracts the predator this little
squid is called the fire shooter because
of its ability to do this
now it may look like a tasty morsel or a
pig’s head with wings
but if it’s attacked it puts out a
barrage of light in fact a barrage of
photon torpedoes I just barely got the
lights out in time for you be able to
see those gobs of light hitting the
transept screen and then just glowing
it’s phenomenal so there’s a lot of
animals in the open ocean most of them
that make light and we have a pretty
good idea for most of them why they use
it for finding food for attracting mates
for defending against predators but when
you get down at the bottom of the ocean
that’s where things get really strange
and some of these animals are probably
inspiration for the things you saw in
Avatar
but you don’t have to travel to pandora
to see them there are things like this
this is a golden coral a bush it grows
very slowly in fact it’s thought that
some of these are as much as 3,000 years
old which is one reason that bottom
trawling should not be allowed the other
reason is this amazing bush glows so if
you brush up against it anyplace you
brushed against it you get this
twinkling Bluegreen light it’s just
breathtaking
and you see things like this this looks
like something out of a dr. Seuss book
just all manner of creatures all over
this thing and these are flight wrapping
enemies now if you poke it it pulls in
its tentacles but if you keep poking it
it starts to produce light and it
actually ends up looking like a galaxy
it produces these strings of light
presumably as some form of defense
there are starfish that can make light
and there are brittle stars that produce
bands of light that dance along their
arms this looks like a plant but it’s
actually an animal and it angers itself
in the sand by blowing up a balloon on
the end of its stock so it can actually
hold itself in very strong currents as
you see here but if we collect it very
gently and
bring it up into the lab just squeeze it
at the base of the stock it produces
this light that propagates from the stem
to the plume change in color as it goes
from green to blue colorization and
sound effects added for your viewing
pleasure but we have no idea why it does
that
here’s another one this is also a see
pen it’s got a brittle star hitching a
ride it’s a green saber of light and
like the one you just saw it can produce
these as bands of light so if I squeeze
the bass the band’s go from base to tip
if I squeeze the tip they go from tip to
base so what do you think happens if you
squeeze it in the middle I’d be very
interested in your theories about what
that’s about so there’s a language of
light in the deep ocean and we’re just
beginning to understand it and one way
we’re going about that is we’re
imitating a lot of these displays this
is an optical lure that I’ve used we
call it the electronic jellyfish it’s
just sixteen blue LEDs that we can
program to do different types of
displays and we view it with a camera
system I developed called I in the sea
that uses far red light that’s invisible
to most animals so it’s unobtrusive so I
just want to show you some of the
responses that we’ve elicited from
animals in the deep sea so the camera is
black and white it’s not high resolution
and what you’re seeing here is a bait
box with a bunch of like the cockroaches
of the ocean they’re isopods all over it
and right in the front is the electronic
jellyfish and when it starts flashing
it’s just going to be one of the LEDs
that’s flashing very fast but as soon as
it starts to flash and it’s going to
look big because it blooms on the camera
I want you to look right here and it’s
something small there that responds
we’re talking to something it looks like
a little string of pearls basically in
fact three strings of pearls this was
very consistent this is in the Bahamas
at about 2,000 feet we basically have a
chat room going
on here because once it gets started
everybody’s talking and I think this is
actually a shrimp that’s releasing its
bioluminescent chemicals into the water
but the cool thing is we’re talking to
it we don’t know what we’re saying
personally I think it’s something sexy
and then finally I want to show you some
responses that we recorded with the
world’s first deep-sea webcam which we
had installed in Monterey Canyon last
year we’ve only just begun to analyze
all of this data this is going to be a
glowing source first which is like
bioluminescent bacteria and it is an
optical cue that there’s carrion on the
bottom of the ocean so this scavenger
comes in which is a giant sixgill shark
and I can’t claim for sure that the
optical source brought it in because
there’s bait right there but if it had
been following the odor plume it would
have come in from the other direction
and it does actually try to seem to be
trying to eat the electronic jellyfish
that’s a 12-foot long giant sixgill
shark okay so this next one is from the
webcam and it’s going to be this
pinwheel display and this is a burglar
alarm
and that was a Humboldt squid a juvenile
Humboldt squid about three feet long
this is at 3,000 feet in Monterey Canyon
but if it’s a burglar alarm you wouldn’t
expect it to attack the jellyfish
directly it’s supposed to be attacking
what’s attacking the jellyfish but we
did see a bunch of responses like this
this guy’s a little more contemplative
hey wait a minute there’s supposed to be
something else there he’s thinking about
it but he’s persistent he keeps coming
back and then he goes away for a few
seconds to think about it some more
and thinks maybe if I come in from a
different angle
nope so we are starting to get a handle
on this but only just the beginnings we
need more eyes on the process so if any
of you ever get a chance to take a dive
in a submersible by all means climb in
and take the plunge this is something
that should be on everybody’s bucket
list because we live on an ocean planet
more than 90% 99% of the living space on
our planet is ocean it’s a magical place
filled with breathtaking
light shows
and bizarre and wondrous creatures alien
life-forms that you don’t have to travel
to another planet to see but if you do
take the plunge please remember to turn
out the lights but I warn you it’s
addictive
thank you