When the larger fish of a species
get killed off, the gene pool changes,
the average size of the fish shrinks,
and the species become threatened.
So it was alarming news when we
learned that the mighty whale shark,
is suffering from a severe decline in
size. Australian scientist Dr. Mark
Meekan says that observation logs
of whale sharks in Ningaloo Reef,
Western Australia, suggest that the
average size of the fish had shrunk
from 23 feet in 1995 to 18 feet today,
only 10 years later. In search of the
ingredients for shark fin soup for
Asian banquets, fishermen shoot,
harpoon, or do whatever is necessary
to slow the fish, then remove the fins,
leaving the carcass for other sharks.
"Any fish population that is
undergoing unsustainable mortality
usually shows a drop in average
size of individual fish, and a drop
in abundance," said Meekan. "What
we're seeing at Ningaloo is particularly
worrying, because these waters
are protected. If we're losing the
adults in the population, leaving only
juvenile whale sharks, then we'll have no population there to reproduce."
Yet some divers who spear fish
aren't helping. In two cases that
made the U.S. press, divers went after
huge trophy fish, with no concern for
the endangered nature of the species
they were pursuing.
The St. Petersburg (FL) Times reported in July that diver Dan
MacMahon, had speared a 400-
pound Warsaw grouper in 425 feet of
water. The Warsaw grouper is listed
as "critically endangered" by the
World Conservation Union.
In a lurid account posted on www.spearboard.com, then criticized on
other bulletin boards, MacMahon
described his kill as a "mission" he'd
spent the last year "plotting and planning"
to "finally get the big Warsaw
I've wanted all my life." When he
reached a wreck on the bottom,
MacMahon says, "There were a half
dozen Warsaws in the 40-100 lb.
range close to us when I spotted the
monster facing me about 100 feet
away."
When the fish approached him, MacMahon boasts, "I pointed my 52-
inch SS Hornet and slammed a free
shaft into the sweet spot." When the
fish "started shaking back and forth,"
says MacMahon, "I slammed shaft
number two into his head." Then, as
a coup de grace, he says, "I put a PH
[power head] on my kill spike and
slammed into his head." After wrestling
the huge fish to the surface, it
took four men and a block and tackle
to get it on the boat.
"What an awesome dive," says
MacMahon. "There's (sic) just too
few moments like this in ones (sic)
life." To which we can only add,
"good thing."
In Southern California, according
to the San Diego Union-Tribune,
lifeguards witnessed Navid Adibi, 22,
driving a boat into the San Diego-La
Jolla Ecological Reserve on April 24,
past a bright yellow buoy marking its
boundaries. Two men put on scuba
gear and loaded spear guns. About
20 minutes after they entered the
water, the men surfaced and the
boat operator helped them lift a
171-pound protected giant sea bass aboard; the group celebrated with
high-fives before motoring out of the
reserve. Authorities intercepted the
boat.
Adibi, the boat driver, an undocumented
Iranian emigrant with a
police record, was fined $500. The
man who speared the fish, Omid Adhami, 34, was placed on probation.
" Atlantic swordfish used to grow to more
than 1,000 pounds, but the average one
caught in 1995 weighed just 90 pounds." |
Despite these wrist slap punishments,
trophy hunting for endangered
species or in marine reserves
is unconscionable in an era with so
much pressure on fish populations.
Terry Maas, legendary spear fisherman,
author and video maker, points
out that a 430-pound, slow-growing
California giant black sea bass would
be 75 years old. He compares that
venerable specimen with a 400-
pound bluefin tuna, only 11 years
old, that he took while free diving.
"Obviously," Maas concludes, "tuna, with their rapid growth, can replace
large adults in their population in
one-seventh the time it takes black
sea bass populations to replace a similarly
sized fish."
John Hyde, of the National
Marine Fisheries, adds, "It's never
good to take exceptionally large fish."
Females are
usually much
bigger than
males. And
larger females
tend to produce
more
and higher quality eggs, "so catching
the biggest fish depletes the female
population," Hyde points out. With
many groupers and other sex changing
species, all the small fish may be
one sex. "By catching all the big fish
you take away all of one sex, reducing
reproductive potential until some of
the remaining small fish can change
sex ... you can see how easy it would
be to alter the average size at which
these species change sex."
News reports of an 1,100-pound
tiger shark being reeled in during
a recent "monster shark derby" at Martha's Vineyard, MA, point out
that taking trophy fish is hardly exclusive
to spear fishermen. In fact, the
fishing industry tactic of targeting the
biggest members of a species is now
being challenged by new research,
according to an article in Science News.
Fleets target big fish because they
yield more marketable meat. And
yet, the biggest species--such as tuna,
sharks, and cod--in heavily fished
areas tend to be the first to plummet,
notes Ransom A. Myers of Dalhousie
University in Halifax, Nova Scotia.
Ensuing populations get smaller with
the disappearance of the "big mammas"
(which often produce the largest
numbers of eggs and the heartiest
offspring). For instance, Atlantic
swordfish used to grow to more
than 1,000 pounds, but the average
one landed in 1995 weighed just 90
pounds--a couple of years short of its
first chance to reproduce.
We divers have a special relationship
to the fish in the sea and with
that comes a special responsibility to
protect them. That can mean giving
your time or money to organizations
that work hard to protect the oceans.
There's not a lot of time.