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Are we interrupting the kinky sex lives of fish?

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    Right now,
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    beneath a shimmering blue sea,
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    millions of fish are having sex.
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    (Cheers)
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    And the way they're doing it
    and strategies they're using
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    looks nothing like what we see on land.
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    Take parrotfish.
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    In this species, all fish are born female,
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    and they look like this.
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    Then later in life,
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    she can transition into a male
    and she'll look like this.
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    But it's not just
    a spectacular wardrobe change.
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    Her body can reabsorb her ovaries
    and grow testes in their place.
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    In just a few weeks,
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    she'll go from making eggs
    to producing sperm.
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    It's pretty impressive,
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    and in the ocean it's also pretty common.
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    In fact, I bet nearly all of you
    have at some point had a seafood dish
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    made up of an individual
    that started life as one sex
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    and transitioned to another.
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    Oysters?
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    Grouper?
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    Shrimp?
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    Seeing some heads nodding, yeah.
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    But not all fish that change sex
    start as females.
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    Those clown fish we know
    from "Finding Nemo"?
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    They're all born male.
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    So in the real world,
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    when Nemo's mother died,
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    Nemo's dad Marlin
    would have transitioned into Marlene --
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    (Laughter)
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    and Nemo would have likely mated
    with his father turned mother.
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    (Laughter)
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    You can see --
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    (Laughter)
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    Yeah.
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    You can see why Pixar
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    took a little creative license
    with the plotline, right?
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    (Laughter)
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    So sex change in the ocean
    can happen in either direction
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    and sometimes even back and forth,
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    and that's just one of the many
    amazing strategies animals use
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    to reproduce in the ocean.
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    And trust me when I say
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    it's one of the least surprising.
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    Sex in the sea is fascinating,
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    and it's also really important,
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    and not just to nerdy
    marine biologists like me
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    who are obsessed with understanding
    these salty affairs.
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    It matters for all of us.
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    Today, we depend on wild caught fish
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    to help feed over two billion people
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    on the planet.
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    We need millions of oysters and corals
    to build the giant reefs
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    that protect our shorelines
    from rising seas and storms.
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    We depend on medicines that are found
    in marine animals to fight cancer
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    and other diseases.
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    And for many of us,
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    the diversity and beauty of the oceans
    is where we turn for recreation
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    and relaxation and our cultural heritage.
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    In order for us to continue
    to benefit from the abundance
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    that ocean life provides,
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    the fish and coral and shrimp of today
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    have to be able to make fish
    and shrimp and coral for tomorrow.
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    To do that, they have to have
    lots and lots of sex.
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    And until recently,
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    we really didn't know
    how sex happened in the sea.
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    It's pretty hard to study.
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    But thanks to new science and technology,
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    we now know so much more
    than even just a few years ago,
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    and these new discoveries
    are showing two things.
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    First, sex in the sea is really funky.
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    Second, our actions are wreaking havoc
    on the sex lives of everything
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    from shrimp to salmon.
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    I know. It can be hard to believe.
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    So today, I'm going to share a few details
    about how animals do it in the deep,
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    how we may be interrupting
    these intimate affairs,
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    and what we can do to change that.
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    So, remember those sex-changing fish?
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    In many places in the world,
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    we have fishing rules
    that set a minimum catch size.
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    Fishers are not allowed
    to target tiny fish.
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    This allows baby fish to grow
    and reproduce before they're caught.
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    That's a good thing.
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    So fishers go after the biggest fish.
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    But in parrotfish, for example,
    or any sex changer,
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    targeting the biggest fish means
    that they're taking out all the males.
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    That makes it hard for a female fish
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    to find a mate
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    or it forces her to change sex sooner
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    at a smaller size.
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    Both of these things can result
    in fewer fish babies in the future.
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    In order for us to properly care
    for these species,
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    we have to know if they change sex,
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    how, and when.
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    Only then can we create rules
    that can support these sexual strategies,
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    such as setting a maximum size limit
    in addition to a minimum one.
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    The challenge isn't that we can't think
    of these sex-friendly solutions.
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    The challenge is knowing
    which solutions to apply to which species,
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    because even animals we know really well
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    surprise us when it comes
    to their sex lives.
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    Take Maine lobster.
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    They don't look that romantic,
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    or that kinky.
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    They are both.
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    (Laughter)
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    During mating season,
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    female lobsters want to mate
    with the biggest, baddest males,
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    but these guys are really aggressive,
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    and they'll attack any lobster
    that approaches, male or female.
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    Meanwhile, the best time
    for her to mate with the male
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    is right after she's molted,
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    when she's lost her hard shell.
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    So she has to approach this aggressive guy
    in her most vulnerable state.
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    What's a girl to do?
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    Her answer?
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    Spray him in the face
    repeatedly with her urine.
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    (Laughter)
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    Under the sea, pee
    is a very powerful love potion.
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    Conveniently, lobsters' bladders
    sit just above their brains,
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    and they have two nozzles
    under their eye stalks
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    with which they can shoot
    their urine forward.
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    So the female approaches the male's den
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    and as he charges out
    she lets loose a stream of urine
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    and then gets the hell out of there.
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    Only a few days of this daily dosing
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    is all it takes for her scent
    to have a transformative effect.
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    The male turns from an aggressive
    to a gentle lover.
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    By the week's end,
    he invites her into his den.
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    After that, the sex is easy.
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    So how are we interrupting
    this kind of kinky courtship?
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    Well, the female's urine
    carries a critical chemical signal
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    that works because
    it can pass through seawater
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    and lobsters have a smell receptor
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    that can detect and receive the message.
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    Climate change is making
    our oceans more acidic.
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    It's the result of too much
    carbon dioxide entering seawater.
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    This changing chemistry
    could scramble that message,
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    or it could damage
    the lobsters' smell receptors.
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    Pollution from land
    can have similar impacts.
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    Just imagine the consequence
    for that female
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    if her love potion should fail.
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    These are the kinds of subtle
    but significant impacts we're having
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    on the love lives of these marine life.
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    And this is a species we know well:
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    lobsters live near shore in the shallows.
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    Dive deeper, and sex gets even stranger.
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    Fanfin anglerfish live at about
    3,000 feet below the surface
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    in the pitch-black waters,
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    and the males are born
    without the ability to feed themselves.
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    To survive, he has to find a female fast.
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    Meanwhile, the female,
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    who is 10 times bigger than the male,
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    10 times,
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    she lets out a very strong pheromone
    with which to attract mates to her.
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    So this tiny male is swimming
    through the black waters
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    smelling his way to a female,
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    and when he finds her,
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    he gives her a love bite.
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    And this is when things get really weird.
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    That love bite triggers
    a chemical reaction
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    whereby his jawbone
    starts to disintegrate.
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    His face melts into her flesh,
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    and their two bodies start to fuse.
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    Their circulatory systems intwine,
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    and all his internal organs
    start to dissolve
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    except for his testes.
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    (Laughter)
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    His testes mature just fine
    and start producing sperm.
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    In the end, he's basically
    a permanently attached
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    on-demand sperm factory for the female.
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    (Laughter)
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    It's a very efficient system,
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    but this is not the kind
    of mating strategy
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    that we see on a farm, right?
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    I mean, this is weird.
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    It's really strange.
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    But if we don't know
    that these kinds of strategies exist
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    or how they work,
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    we can't know what kind of impacts
    we may be having, even in the deep sea.
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    Just three years ago,
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    we discovered a new species
    of deep sea octopus
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    where the females lay their eggs
    on sponges attached to rocks
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    that are over two and a half miles deep.
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    These rocks contain rare earth minerals,
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    and right now there are companies
    that are building bulldozers
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    that would be capable of mining
    the deep sea floor for those rocks.
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    But the bulldozers
    would scrape up all the sponges
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    and all the eggs with them.
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    Knowingly, and in many cases unknowingly,
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    we are preventing successful sex
    and reproduction in the deep.
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    And let's be honest,
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    dating and mating is hard enough
    without somebody coming in
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    and interrupting all the time, right?
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    I mean, we know this.
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    So today, while I hope you will leave here
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    with some excellent bar trivia
    on fish sex --
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    (Laughter)
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    I also ask that you remember this:
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    we are all far more intimately connected
    with the oceans than we realize,
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    no matter where we live.
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    And this level of intimacy
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    requires a new kind
    of relationship with the ocean,
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    one that recognizes and respects
    the enormous diversity of life
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    and its limitations.
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    We can no longer think of the oceans
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    as just something out there,
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    because every day we depend on them
    for our food security,
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    our own health and wellness,
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    and every other breath we take.
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    But it is a two-way relationship,
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    and the oceans can only continue
    to provide for us
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    if we in turn safeguard
    that fundamental force of life in the sea:
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    sex and reproduction.
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    So, like any relationship,
    we have to embrace some change
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    for the partnership to work.
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    The next time you're thinking
    about having seafood,
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    look for sustainably caught
    or farmed species
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    that are local and low on the food chain.
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    These are animals
    like oysters, clams, mussels,
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    small fish like mackerel.
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    These all reproduce like crazy,
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    and with good management
    they can handle a bit of fishing pressure.
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    We can also rethink
    what we use to wash our bodies,
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    clean our homes,
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    and care for our lawns.
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    All of those chemicals
    eventually wash out to sea
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    and disrupt the natural chemistry
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    of the ocean.
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    Industry also has to play its part
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    and take a precautionary approach,
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    protecting sexual activity
    where we know it exists
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    and preventing harm in the cases
    where we just don't yet know enough,
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    like the deep sea.
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    And in the communities where we live,
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    the places we work,
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    and the country in which we vote,
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    we must take bold action
    on climate change now.
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    (Applause)
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    Thank you.
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    (Applause)
标题:
Are we interrupting the kinky sex lives of fish?
演讲者:
Marah J. Hardt
描述:

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Video Language:
English
Team:
TED
项目:
TEDTalks
Duration:
12:22

English subtitles

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