Food Chain in Motion
-- Kevin Sullivan's Tale
In my 27 years as
a special agent with the National Marine Fisheries Service Office ofLaw
Enforcement, I've spent a lot of time on the ocean. But the single most
spectacular event I witnessed took place over twenty years ago in what
is now the Stellwagen Bank National Marine Sanctuary.
I can't quite recall
the date. I believe it was 1978, perhaps 1979. I vividly remember the
day. It was a crisp autumn afternoon. With little wind the water was
like a mirror reflecting the west heading sun. Long, dark shadows followed
the Massachusetts Environmental Police patrol boat. I had joined a day-long
mission with two environmental police officers. We were on the lookout
for fishing vessels taking more than their legal share of giant bluefin
tuna.
Stellwagen Bank,
which had not yet been designated as a National Marine Sanctuary, was,
and still is, a popular fishing spot for the giant fish. You have to
understand a bit about giant bluefin tuna to see why a fishermen would
break the law to catch them. True to their name, giant bluefin tuna
are enormous creatures, weighing as much as 1200 pounds. They can swim
at speeds of up to fifty miles per hour. These fish are called "highly
migratory species" due to their lengthy journeys from sea to shining
sea. Even back then, fisherman make a pretty penny selling these fish
in Japanese markets. They'd place the fish individually into large wooden
coffins, load them onto a 747, then ship them straight to Tokyo, where
dealers would pay up to 25 dollars a pound for them.
If you do the math
you'll understand why catching just one giant bluefin tuna makes for
a profitable day at sea. For obvious reasons, some fisherman would like
to catch more than one. But by federal law, a fishing vessel can take
only one giant bluefin tuna per day. Tuna stocks had become unstable
in the mid-70's due to overexploitation around the world, especially
by distant water longliners. Scientists feared that populations would
collapse if fishing pressure kept up. The state officers and I wanted
to see to it that this didn't happen. We weren't just enforcing the
law out there; we were ensuring the survival of the majestic giant bluefin
tuna. At the same time, we had a genuine concern for maintaining "a
level playingfield" for the fishers who expend significant time and
money in the hunt for their valuable prize. Those who fail to achieve
their catch are said to have been "tuna wishing".
Well, the two officers
and I were merrily making our way along the southwest corner of the
bank, not too far from Provincetown. As always, we tried to be aware
of breaking water to avoid collisions with marine mammals such as the
highly endangered right whale that frequents the Bank. One of us spied
white water splashing about a three iron from our boat. It was a school
of very scared sand eels leaping for their lives above the surface of
the water as hungry bluefish cunningly circled underneath awaiting their
appetizers. The jumping sand eels were a familiar sight, typical of
bluefish feeding frenzies. Pound for pound bluefish are probably the
fiercest fighters in the sea. But they were no match for what we then
saw: a school of bluefin tunas bursting though the water just behind
the bluefish. The table had turned. The predators became the prey. The
bluefish leapt from the water, frantically seeking escape from the powerful
jaws of the encroaching tunas.
Back on the ship
we'd fallen silent as the spectacle of the food-chain in action unfolded
with the shocking appearance of the oceans÷ ultimate force. The tell-tale
traits of bright white on black and the high triangle fins instantly
announced the presence of killer whales in hot pursuit of the marauding
bluefins. Killer whales aren't so common on the bank, but when they're
there, they like nothing more than a bluefin tuna dinner.
My best guess is
that the scene lasted about thirty seconds. I lost track of the time,
though. To me, time stood still, as if the whole event was a snapshot
of a natural process. We could see every level of the food chain at
work, except for the microscopic plant plankton and the somewhat larger
animal plankton that serves as the sand eels' food. Looking back, I
realize that if I'd had a good camera handy, I could have taken a picture
that would have enabled me to retire twenty years early!
