February 14, 2005
Deep Hooks: In or Out?
by Ralph Manns
Those of us who try to share the findings of scientific study with
non-scientists are often frustrated. It seems very difficult to
get the word out. We write about some important discovery, but find
anglers, particularly the influential professional and TV bass anglers,
either don't read the new information or dismiss the new scientific
insights because they conflict with beliefs the anglers already
Professional and TV anglers aren't the only ones to be slow in learning
and applying the latest "word" from scientists. Biologists,
particularly state fisheries workers are often too busy with their
own assigned tasks to read all of the literature produced by other
scientists. They continue to advise anglers to handle fish using
The recommendation that anglers cut the leader close to the hook
when bass are "deep-hooked" is a good example. It is hard
to find a publication on catch-and-release (C&R) techniques
that doesn't pass on this poor advice. Yet, recent research on release
techniques strongly suggests there is a better way.
Some years ago, Doug Hannon noted that most magazine articles and
state publications recommend leaving hooks in bass and other fish
to "rust" out. He reported that hooks don't rust fast
enough, even in salt water; and suggested that the shank of a hook
pointing up the throat of a bass acts like a lever or trap door
that prevents swallowing. Bass can die of starvation while waiting
for normal body processes to eject the hook. Food coming down a
bass' throat will bypass a hook-shank, IF the shank lies tightly
against the side of the throat where the barb is lodged. However,
if the shank protrudes into the throat, food coming down can push
the shank across the esophagus, blocking it. Deep-hooked bass may
even feel pain as the food rotates the barb and regurgitate the
Recently, Hannon's observations have been scientifically verified.
John Foster, Recreational Fisheries Coordinator for the Maryland
Department of Natural Resources, studied striped bass at Chesapeake
Bay. His researchers held throat-hooked stripers between 16- and
28- inches long for observation in half-strength seawater so that
hooks had ample opportunity to rust away. Size 1/0 and 2/0 stainless
steel, bronzed, nickel, tin, and tin-cadmium plated hooks were hooked
in the top of each fish's esophagus, with an 18-inch length of line
connected to the hook.
After four months, 78 percent of the hooks were still imbedded.
Cadmium coated hooks poisoned 20 percent of the fish, and production
of these hooks has been stopped. Bronzed hooks were less likely
(70%) to be retained than tin-cadmium (80%), nickel (83%), or stainless
steel hooks which were all retained (100%).
In a second test, the line was clipped either at the eye of the
hook as advised by most existing C&R guides, or well outside
the fish's mouth, . One-hundred percent of the stainless hooks were
again retained, while 56 percent of tin, 76 percent of bronze, 84
percent of tin-cadmium, and 88 percent of nickel hooks remained.
Fish mortality was greater when all line was trimmed. Foster suggested
that the lengths of line hanging from a fish's mouth kept the hook-
shank flat against the side of the esophagus and allowed food to
pass. Without the line, food could move the hook and close the throat.
Hooks rusted slowly in stages, and the bend and barb became smaller
very gradually. Stripers formed scar tissue around imbedded hook
points, a typical reaction of body tissue to foreign matter. Foster
noted, however, that once the tough scar tissue formed, hooks became
more, not less, difficult to remove. Months after fish were hooked,
infections sometimes developed around points, causing some deaths.
Based on this research, Foster recommended anglers carefully remove
even deeply imbedded hooks. If a hook can not be removed, then it
seems better to leave about 18 inches of line attached.. Perhaps,
someday, these findings will reach C&R anglers, the biologists
who are researching C&R and publish C&R guidelines, and
TV anglers who teach by their example.
Removal is usually best for a released bass. But, the hook should
be easily reached. A back up option is to carry a specially designed,
slim-necked tool called the D-Barb to reach and cut off barbs and
points of any hooks you can not rotate out.. To be strong enough
to cut or crush down the barbs of heavy hooks like True-Turn Brutes,
the tool usually must have heavy jaws and long handles but not be
too wide.. Forcing large wire-cutters into the gullet of small bass
can do as much damage as leaving a hook in place.
Best for the fish is using barbless hooks. They greatly reduce hook
damage to all mouth tissues and rotate out easily. (See the through-the-gills
Texas researchers compared the mortality of largemouth bass hooked
with live bait and artificial lures. Their main finding: "there
is no biological justification to regulate use of live bait to catch
bass" has been widely publicized. Their other findings may
help anglers make appropriate adjustments in technique.
In two separate tests, largemouth bass in a private water were landed
by TPWD anglers using Carolina-rigged scented plastic worms, crankbaits
with multiple treble hooks, and live carp fished with either a Carolina
rig or a float. To simulate normal fishing conditions, anglers with
different levels of expertise were used.
While fishing with floats, anglers were instructed to delay hooksets
until floats went completely under, simulating the way typical amateur
anglers fish with unattended rods. Under all other conditions, anglers
were to strike immediately upon feeling a hit. Captured bass were
immediately examined to identify hook-related injuries. When bass
were hooked deep in the throat, the line was cut and hook left in
place. (TPWD did not identify whether the cut was made in the traditional
way near the hook, or with line remaining outside the fish's mouth.)
Bass were then kept in a large holding net over a 72-hour observation
period to determine short-term mortality rates. Sixty bass were
taken using each method. Tests were made in August, when water was
warm and stress and mortality are normally high.
The average mortality under these worst-case conditions was 22 percent.
Carolina rigs with flavored worms caused the highest mortality,
followed by live carp used under floats, crankbaits, and Carolina-rigged
TPWD biologists concluded that the timing of the hookset appeared
more critical than the type of bait used in the determination of
short-term death rates. The data show bass hooked in the throat
had poor survival odds. Evidently, largemouth bass took both lures
and live bait fully into their mouths almost immediately. The bass
pros' advice to strike without delay is important to reduce mortality.
Angling techniques that delay hooksets should be avoided.
Carolina-rig and worm combos likely killed more fish because the
lengthy leaders prevented immediate detection of some strikes and
flavored worms are quickly and easily swallowed. Eighteen percent
of bass taken on Carolina rigs with worms were throat-hooked.
In contrast, Carolina rigs with live bait and live baits under floats
caused less mortality, likely because live preyfish are often held
in a bass' mouth for a few seconds, killed, and turned to be swallowed
headfirst. This gives anglers a few seconds more to detect hits
before baits are ingested. The decision to delay hits when live
baits were used with floats and to strike immediately with Carolina-rigged
baits likely caused the different mortality rates of these two techniques.
Nevertheless, 10 percent of bass hooked on Carolina-rigged live
baits were hooked in the esophagus. It is no surprise that crankbaits
are less likely to be swallowed, as their artificial nature is immediately
detectable to fish.
When fisheries are managed primarily for C&R or trophy bass
production, it may be appropriate to ban use of multiple rods to
reduce delayed hooksets, or to limit lures to items unlikely to
be swallowed. In any case, C&R sportsmen will want to avoid
techniques that delay hooksets, like fishing with unattended rods.
The TPWD study showed that bass hooked in the tongue and esophagus
had about a 50 percent chance of dying, while bass hooked in the
lips mouth, jaw, roof of mouth had 25 percent or less mortality.
Interestingly, only 12.5 percent of gill hooked fish died. This
finding suggests anglers who kill and eat or mount gill-damaged
bass because "they are unlikely to live" are in error.
TPWD also compared the survival of bass when they were bleeding
and when leaders were cut and hooks left in the fish. Removing hooks
improved bass survival when bass were not bleeding. But there was
little difference in mortality when bass were bleeding or hooks
were left in the fish.
When I read that some anglers removed hooks by working through the
gill slits several years ago, I reacted negatively, assuming excess
damage would occur. But, upon reflection on the normal function
and resistance of gills to external damage, I decided to test the
procedure for myself. In a private pond with barbless hooks I've
now made over 1000 gill-slit removals of barbless hooks without
any observed fish deaths or apparent bleeding or gill damage. Several
individual bass with identifying marks have been caught again and
again. Although some unobserved delayed deaths are likely, if the
procedure was exceptionally hazardous I likely would have seen several
Despite their fragile appearance, the gills of bass are one of the
strongest and most disease resistant structures of the bass, equivalent
in resistance to skin of the lower jaw that we grasp so handily.
After all, the gills are constantly exposed to outside influences.
The prey the bass eats brush against them, and many prey are caught
because they are sick and carrying diseases. Prey with spines cut
and stab bass in the gill areas. With food, bass often ingest goop
and disease laden muck from the bottom. Moreover, each breathing
gill movement brings whatever bacteria, viruses, and dirt is in
the water over the filaments. To function, gills must be tough.
Light contact isn't likely to damage gills or introduce disease.
They are as resistant as the fish's skin to light contact.
Still caution is needed. Gill filaments, the red comb-like elements,
are not reversible. Like a flag, they naturally stream with the
flow. They never should be forced back toward the mouth by a tool
or by reverse water pressure. Swishing a bass or any other fish
back and forth to "revive it"can do more harm than good.
If the fish need to be revived by more oxygen, move it slowly forward
through the water. But, do not force water down its throat by moving
it rapidly into a current.
By using barbless hooks that reverse easily, an entry through the
gill slit can often be used when entry through the mouth is impractical
or impossible with typical tools. A small, narrow pair of long-nosed
pliers should be used, so the tool can be rotated without putting
pressure on the gill arches. If an angler is particularly clumsy,
or careless, the procedure could cause significant damage, making
leaving a hook and long leader in the bass a better option with
higher odds of survival.
Anglers practicing C&R rather than eat legal bass or legally
abiding with a slot limit might note these findings. Fish caught
with only superficial wounds are likely to survive release. Small,
deeply-hooked, bleeding, and legal bass likely should be eaten,
rather than released to die later. Slot bass must be released in
as healthy a condition as possible. And lunker bass are so rare
and valuable in any fishery that they should be immediately released,
even if they are bleeding or deeply-hooked. Remove the hook if possible,
but leave an 18-inch leader if you can not remove the hook.
This article is protected by copyright, and may be reprinted for
public use only with my written permission. However, I want the
information in this article to get maximum exposure to other anglers,
so reprinting of this specific article is encourage when permission
is obtained. firstname.lastname@example.org)