Page 346 - The Tigris Expedition

The Tigris Expedition
across the back, they stood evenly spaced, with freedom for their
outstretched breast fins, and always on port side, and always with
our bow a short distance ahead of their own front line, as if to be
sure that we led the way. No matter what speed we made, theirs
was the same. By day they were lively, swift, and even seemed
playful. In rough seas they would amuse themselves wagging their
tails at full speed to rush right up to the highest peak of a wave top,
then calmly surf-riding down the steep side.
As the month ended a note in the diary says:

We are so much part of the marine environment now that I
regard the dolphin school as domesticated; they always change
speed and direction to go with us whenever we make a change.
And at port side gunwale they swim so close that the tailfin often
cuts the surface beside us, and with a flashlight in their faces we
can see every detail. In daytime they often swim with their white
lips open as if to collect plankton; we can then see their pink
tongues. In daytime also, the breast-fins, spread out like on a
butterfly, are shining so intensely in light blue that they seem to
be illuminated and can normally be seen before the fish itself
becomes visible. While pale silver at night and when dead, this
parrot-coloured chameleon of the sea is otherwise almost brown
on its back, with grass-green head and yellow-green tail-fin, the
rest of the body in various tones of green that alters and moves
with the direction of sun and shade. A beauty to look at that none
can help admiring or tire of, even though we see it all the time.
They even leave us with an impression of being a friendly and
faithful marine herd, by following us as dogs and sheep follow a
shepherd ashore.

We sometimes sailed into an area with a side current rich in
plankton. At night the sea was phosphorescent with microscopic
organisms that gave a faint glow to anything touching them, fish or
reeds, while some less numerous, bigger plankton twinkled as
individual sparks. Sea and sky could sometimes be confused. The
dolphins then showed up without flashlight as pale, elongated
clouds drifting over a pitch-black firmament, and the phosphores­
cent micro-plankton made each fish send out a faint light even in its
wake, giving them a long extra tail as if they were giant luminescent
tadpoles. When we used a fine-meshed net to catch the star-like
sparks that danced about independently, they proved to be
copepods: tiny jumping shrimps with big black eyes.
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