#2: EMBARGOED PRESS RELEASE
STRICTLY UNDER EMBARGO UNTIL 12:00PM NOON ET (US) ON THURSDAY, JANUARY 7,
2016
Region(s) of Interest: United Kingdom, Norway
Institution(s): Scottish Association for Marine Science; University Centre in Svalbard
In arctic winter, marine creatures migrate by the light of the moon (VIDEO)
A few months ago, researchers reported the surprising discovery that
marine creatures living in one Arctic fjord keep busy through the
permanently dark and frigid winter months
(http://www.eurekalert.org/pub_releases/2015-09/cp-itd091715.php).
Now, a report in the Cell Press journal Current Biology on Jan. 7, 2015,
extends this activity to the whole of the Arctic. They also find that, in the
absence of any sunlight, it's the moon that drives the vertical migrations of
tiny marine animals.
The behavior is most likely an attempt by zooplankton to avoid predators
hunting by moonlight, the researchers say.
"During the permanently dark and extremely cold Artic winter, [these] tiny
marine creatures, like mythical werewolves, respond to moonlight by
undergoing mass migrations," says Kim Last of the Scottish Association for Marine Science in Scotland.
No matter where the researchers looked during the Arctic winter -- in fjord, shelf, slope, or open sea -- they
observed the same behavior. Further investigation showed that the marine creatures had shifted their activities
from following the 24-hour solar day to following the 24.8-hour lunar day.
In winter, zooplankton's vertical migrations take place when the moon rises above the horizon, the researchers
report. In addition to this daily cycle, they also discovered a mass sinking of zooplankton from the surface
waters to a depth of about 50 meters every 29.5 days in the winter, coinciding with the full moon.
"The most surprising finding is that these migrations are not rare or isolated to just a few places," Last says.
"The acoustic database used for our analysis cumulatively spans 50 years of data from moorings that cover
much of the Arctic Ocean. The occurrences of lunar migrations happen every winter at all sites, even under sea
ice with snow cover on top."
The findings have implications for the carbon cycle, which is particularly important in light of climate change.
"The daily vertical migration of zooplankton contributes significantly to the carbon pump by moving fixed
carbon from the surface into the deep ocean," Last explains. "Since there is no photosynthesis during the polar
night, carbon is only moved into the deep by predators feeding on prey."
This influence of zooplanktons' winter movements will need to be quantified and incorporated into
biogeochemical models. As the climate changes and the ice melts, Last says, lunar-driven zooplankton
migrations might "become more prevalent, though as yet, we do not know the consequences of this."
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The work was funded by UK's Natural Environmental Research Council and the Research Council of Norway.
Current Biology, Last et al.: 'Moonlight Drives Ocean-Scale Mass Vertical Migration of Zooplankton during the
Arctic Winter' http://dx.doi.org/10.1016/j.cub.2015.11.038. Link to the paper at: http://www.cell.com/currentbiology/abstract/S0960-9822(15)01432-3
Related Files
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A video abstract (also embargoed) can be embedded from
YouTube: https://www.youtube.com/watch?v=eB96vUrqX1M
This Dropbox contains a PDF of the paper proof, the raw video abstract file, and the images/movies
below: https://www.dropbox.com/sh/ftlcwt4bp2pz05q/AAArNe2Q-ore2ymNMLbg-QWUa?dl=0
Image 1: Arctic moon rise. Image credit: Geir Johnson (Norges Naturvitenskapelige Universitet,
NTNU, and University Centre in Svalbard, UNIS).
Image 2: Author Kim Last on field work collecting zooplankton in Isfjorden, Svalbard at midday in
January; sun lotion not necessary. Image credit: Jorgen Berge (The Arctic University of Norway, UiT,
and University Centre in Svalbard, UNIS)
Image 3:Calanus finmarchicus, the main herbivorous zooplankton prey species in the Arctic Ocean.
Image credit: Kim S. Last (Scottish Association for Marine Science, SAMS).
Movie 4: Lunar time-lapse taken at Ny-Ålesund, Svalbard in January showing the rise and passage of
the moon now known to drive lunar vertical migrations (LVMs) of zooplankton. Credit: Johnathon
Cohen (University of Delaware).
Image 5: Moon rise over Kongsfjorden in Ny-Ålesund, Svalbard where an acoustic mooring (ADCP) is
positioned on the seabed and used to track zooplankton migrations. Image credit: Jorgen Berge (The
Arctic University of Norway, UiT, and University Centre in Svalbard, UNIS).
Image 6: Themisto libellula, an amphipod crustacean and a predatory hunter of copepods such as
Calanus—a probable werewolf of the Arctic. Image credit: Daniel Vogedes (The Arctic University of
Norway, UiT).
Author Contacts:
Kim Last
kim.last@sams.ac.uk
Landline (until Jan. 7, 2015): 00-44-0-1631-559414
Mobile (after Jan. 7, 2015): 00-44-0-7840892077
After this co-author, contact:
laura.hobbs@sams.ac.uk
Mobile: 00-44-0-7854319223
Media Contacts:
Euan Patterson
Communications and Media Officer
01631-559342 (direct dial) 01631-559000 (switchboard)
euan.paterson@sams.ac.uk (away until 4th Jan)
Anuschka Miller
anuschka.miller@sams.ac.uk