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    A Neon Sign Of Climate Change
    By Danna Staaf | December 14th 2011 08:52 PM | 1 comment | Print | E-mail | Track Comments
    About Danna

    Cephalopods have been rocking my world since I was in grade school. I pursued them through a BA in marine biology at the University of California...

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    Squids are mercurial, unpredictable creatures of extremes.

    Call them abundant, call them quite rare
    It depends on the climate--the sea and the air
    One species expands, another contracts
    These are the data, these are the facts
    Sometimes it feels like they're growing too fast
    But it helps them respond and it's why they can last
    Through environmental change . . . 

    I've been talking a lot about Humboldt squid recently, and their ability to respond to poor conditions by simply staying small. If they spawn when they're little, they can't make as many babies, but at least they can keep the population going, until the going gets good again.

    Well, Humboldt squid aren't the only ones responding to environmental variability in the Pacific Ocean. Their close cousins, the neon flying squid (Ommastrephes bartramii), have their own set of tricks.

    Date 1870 Source Report on the Invertebrata of Massachusetts Augustus A. Gould, W. G. Binney Author Mary Peart
    Both the neon flying squid, pictured here, and the Humboldt squid (sometimes also called a flying squid) are in the family Ommastrephidae.

    In fact, scientists have a better grasp of neon flying squid biology than of Humboldt squid biology. Some scientists think that neon flyers might serve as a kind of indicator, their abundance illustrating general conditions in the northern Pacific--conditions that affect all kinds of other creatures, too, from monk seals to sea turtles.

    We're still figuring out exactly when and where Humboldt squid spawn and migrate, but these details are pretty well understood for neon flyers. They spawn in the subtropics and feed in the subarctic, following one of two migration patterns. Those that spawn in the autumn get lots of food and grow quite large, while those that spawn in the winter-spring get less to eat and don't grow as big.

     1-11. Image Use This media file is licensed under the Creative Commons Attribution License - Version 3.0. Copyright © Richard E. Young


    What's curious is that the "autumn cohort" is actually defined by size: mantle length greater than 34 cm. So individuals born in autumn can still end up in the winter/spring cohort--if they don't get enough food as babies, they won't make the migration up to the farther-north feeding ground, and they'll never get big enough to join the autumn cohort.

    A group of Japanese researchers has just figured out that that's exactly what happened in 1999-2002, when climatic conditions in the Pacific went topsy-turvy. 

    The spawning ground of the autumn cohort exists in a particular region called the Transition Zone Chlorophyll Front. You may recognize chlorophyll as the green stuff that plants use to photosynthesize, and if you're a whiz with oceanography, you may also know that oceanographers use chlorophyll as a proxy for productivity. Water containing more chlorophyll is more productive--full of nutrients that will trickle up the food chain, from plants to grazers to predators.

    But high-productivity water is often pretty cold water, and baby neon flyers, just like baby Humboldts, like it warm. So spawning grounds for neon flyers need to have both warm water for spawning, and high-chlorophyll water for nutrition.

    Now, check out the red dotted boxes in the two images below:



    Those boxes are the spawning grounds for the autumn cohort of neon flyers. In the image on the left, you can see that the spawning ground contains both warm spawning water (yellow) and cool nutritious water (green). But in the spawning ground on the right, there's very little green nutritious water.

    When the ocean matches the image on the right, as happened in 1999-2002, neon flyer babies don't get much to eat, don't grow as big, and--you guessed it--don't end up in the autumn cohort. Indeed, in these years, the researchers found a much lower stock of adult autumn-cohort squid--hence the titles of the two images.

    What's really interesting is the immediacy of the response. Squid grow so quickly that you can see the effect on adults in the same year that babies were affected. In the words of Ichii et al.,
    The bottom-up effect of the climate shift showed that neon flying squid respond quickly to large-scale environmental changes. . . . Thus, neon flying squid can act as real time ecosystem indicators and productivityintegrators.
    Or, to continue my homage to Billy Joel:

    Darling, we do know why squid go to extremes
    If chlorophyll's low, then they won't grow, that's what I mean,
    And if they spawn in the fall
    They will still be very small
    Darling, we do know why squid go to extremes



    ResearchBlogging.orgIchii, T., Mahapatra, K., Sakai, M., Wakabayashi, T., Okamura, H., Igarashi, H., Inagake, D.,&Okada, Y. (2011). Changes in abundance of the neon flying squid Ommastrephes bartramii in relation to climate change in the central North Pacific Ocean Marine Ecology Progress Series, 441, 151-164 DOI: 10.3354/meps09365

    Comments

    Poems!

    For our sons and daughters too

    when all of what we are today
    is dim dim distant past
    a racial memory mostly myth
    known to the shaman caste

    i wonder what they'll think of us
    when sitting by the fire
    and hearing of the things we did
    like gods but so much higher

    "the great great gods of long ago
    they walked upon the moon
    they drank the very blood of earth
    from death they were immune"

    "they did not walk upon the ground
    but through the air they flew
    and everything there is to know
    the ancient gods they knew"

    i guess the stories that they tell
    the children will devour
    they'll dream that they were just like us
    and had enormous power

    i doubt they could imagine though
    the real truth to tell
    of how we raped their planet
    and we made our lives a hell

    they'll never know the polar bear
    the tiger or the crane
    and countless other creatures
    to which we were the bane

    they'll also never know the stars
    because we stole their chance
    because we'd rather party on
    and live upon advance

    oh what a sad sad species
    we "gods" of planet earth
    we stupid kings of overshoot
    what really are we worth?

    just look around at what you see
    and ask yourself "where now?"
    and if you have an answer
    it better tell you how

    'cause i can't see a future
    that is anything but grim
    and even bare survival chances
    often seem so slim

    i hope that future stories
    are told around the fire
    that kids enjoy just living
    and old folk just retire

    i hope we're not the last of us
    i really really do
    i hope that there's a future
    for our sons and daughters too

    pop

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