Jellyfish
1999
will undoubtably be denoted as a "good jellyfish year". These
creatures seem to drift North with the Gulf Stream and the currents,
doing little harm unless the collide in numbers at a fish or salmon
farm where they cover everything in a green slime.
However,
they have their uses. Marine turtles feed voraciously on jellyfish.
As with racing
pigeons, scientists suspect that they too may navigate over
thousands of miles utilising the earth's magnetic field. They may
also have some kind of mental map of the oceans in which they live.
Previous
research utilised numbered tags - as with fish - but these
proved unsatisfactory.
Current
research utilises tiny radio transmitters weighing just 50 grams
and linked to polar-orbiting NASA satellites.
Similarly,
the RSPB is fitting similar transmitters on to Scottish ospreys
so that their movements on their migration routes down to the West
coast of Africa can be plotted.
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