A first look at realism - A Fascination for Fish: Adventures of an Underwater Pioneer - page 36

to the surface, the fish can die. The gas in the swimbladder obeys the
laws of physics and expands as it encounters the lower water pressure
near the surface. Unfortunately, these fish are not able to release the
rapidly expanding gas very quickly. The result is that the swimbladder
inflates to the point where it can actually force the stomach out of the
fish's mouth. Other unpleasant and usually fatal results are popped eyes
and a terminal case of the bends.
The few species of rockfish that live in shallow water are generally
less colorful, and the deepwater species with their attractive shades of
red come up either dead or dying when collected by conventional meth-
ods. This is fine for the dinner table, because rockfish are excellent eat-
ing, but not so good for the aquarium collector. (On the positive side,
my profession is one of very few where you get to eat your failures.)
Colorful rockfishes, though common lying on ice in the fish market,
became a personal challenge for me, and I racked my brain trying to
come up with a practical method that would give us live, healthy, and
colorful rockfish for display in an aquarium.
I took on this rockfish challenge in 1962 at Marineland of the Pacific.
My first, somewhat harebrained, scheme involved the Mark I decom-
pression tank, which was intended to allow the fish to adjust slowly to
the lower pressure at the surface. Actually, it was a home pressure cooker,
which I modified so that either oxygen or air could be bubbled into it
at about the same pressure found at the depth the fish was captured.
A pressure regulator maintained the pressure and at the same time re-
leased excess gases. Over several hours the pressure was gradually re-
duced; then the cooker was opened up and, hopefully, the live, de-
compressed fishes taken out. We took the pressure cooker down with
us when we dove, and as we collected the rockfish by hand net we put
them in the pot and sealed the lid.
Logistically, the di‹culties multiplied when Marineland's curator, John
Prescott, built a large, heavy pressure tank—the Mark II decompres-
sion chamber. When it was full, a boom and winch were required to lift
and lower the tank into the water, and there was no communication
between diver and crane operator. Because the fish still had to be caught
by hand, we were also limited to diving depths that were safe for us hu-
mans, and these were rarely deep enough to find the colorful species.