On Mon, May 16, 2011 at 7:55 PM, Carolyn Ehle <[log in to unmask]> wrote:
> We were recording spiny lobster behavior sounds in a freestanding salt
> water tank on a hilltop......
>
I think that a freestanding tank does not apply to Randy's question, since
he is talking about long distance transmission for whale communication. All
electromagnetic frequencies are transmitted by salt water to some extent,
but the extent varies. So, for example, certain wavelengths in the visible
spectrum (colours) are differentially absorbed so that some colours are lost
first as you go deeper. The time I took Allen and Aaron diving off Prince
Edward Island we did not go so deep, so I could still see Allen turning
green (he had just started diving).
I personally think sound communication is much more important to whales than
EMF. And the sound pollution in the oceans is horrendous. Salt water is an
excellent transmitter of sound frequencies. It is postulated that whales
may do much of their sound making around the thermocline depth. At that
depth the differential density of water above (from temperature) and below
(from pressure) tends to focus the signal along that depth so that the
signal dissipates only as a square root, instead of the cube root one would
expect from three dimensions. With powerful sounds, like from humpbacks,
they may have been in contact over large distances before sound pollution.
By the way Carolyn, I once helped record the rasps of spiny lobsters
(panulirus versicolor) in West Australia (not in a tank). Do you have any
idea what they are communicating? They also have magnetoreception.
To get back to bees: I really wish people could get past the unfortunate
reference to CCD and look at the more interesting aspects of the study.
Unless I have missed something, nobody has really challenged the results of
the study, that bees are able to pick up those cell phone frequencies. Bill
says, sure the cell phone was right under the hive..... Ok, forget CCD and
lets move the cell phone farther now to see just what their sensitivity is.
Not because we think it is causing CCD, but because it is an interesting
feature of bees that we don't know about.
Do you know how bees do their magnetoreception? I certainly don't, and my
reading doesn't really lead me to believe anyone really completely knows
much about the process.
From Hsu (Magnetoreption in Honeybees) in Science, 1994:
Magnetoreception by honeybees (*Apis mellifera*) is demonstrated by such
activities as comb building and homing orientation, which are affected by
the geomagnetic field. In other magnetoreceptive species, iron oxide
crystals in the form of magnetite have been shown to be necessary for
primary detection of magnetic fields. Here it is shown that trophocytes,
which are apparently the only iron granule—containing cells in honeybees,
contain super-paramagnetic magnetite. These cells are innervated by the
nervous system, which suggests that trophocytes might be primarily
responsible for magnetoreception. Electron microscopy also shows
cytoskeletal attachments to the iron granule membrane.
From Wikipedia:
In bees <http://en.wikipedia.org/wiki/Bees>, it has been observed that
magnetite is embedded across the cellular
membrane<http://en.wikipedia.org/wiki/Cellular_membrane>of a small
group of
neurons <http://en.wikipedia.org/wiki/Neurons>; it is thought that when the
magnetite aligns with the Earth's magnetic field,
induction<http://en.wikipedia.org/wiki/Electromagnetic_induction>causes
a current to cross the membrane which
depolarizes <http://en.wikipedia.org/wiki/Depolarization> the cell.
Here's another, might be interesting for Peter or anyone else who can access
or has paid their subscription:
Honeybees and Magnetoreception
- Nichol, et al.
Science 29 September 1995: 1888-1889.DOI:10.1126/science.269.5232.1888
I haven't looked through apidologie yet, but I have the feeling that we
still have much to learn about the mechanism of magnetoreception, and I wish
we could look at this study as just another facet of that. I wonder if
Jerry has ever noticed any effects from all the sensors he puts in hives. I
know I have sure noticed them attacking spark plug wires on blowers,
trimmers, lawn mowers when they are they are in the mood.
Stan
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