Learn how you can help reduce catch-and-release mortality.
Introduction
Fishing effort in Florida has increased dramatically over the past
decade and is forecast to continue as Florida's resident population
of 14.7 million increases daily by about 1,000 people. More than 40
million tourists visit the state annually, most with coastal
destinations. Fishing is a favorite pastime of Florida's residents
and visitors, and in 1997, saltwater anglers made about 24 million
fishing trips and caught 141 million marine fishes, 71.5 million of
which were released. Because increased exploitation could
negatively impact Florida fisheries, scientists and managers must
remain diligent and innovative in their efforts to utilize fishery
resources wisely and conservatively.
Managers of Florida's fisheries use a combination of traditional
regulations to control harvests and protect fish stocks. These
measures include bag limits, minimum and maximum sizes, closed
seasons and areas, and in some cases, no harvest is allowed unless
a special permit is purchased. Bag limits reduce the number of fish
that are harvested and allocate the catch over time so that the
year's total harvest is not taken in one season. Aggregate bag
limits are sometimes applied collectively to a complex of species
such as grunts and snappers, so that the community is not
overfished. Minimum and maximum sizes, or "slot," limits protect
sexually immature fish and may be imposed to create a "trophy"
fishery, i.e., a fishery that produces extremely large individuals.
Closed seasons and closed areas protect a species during spawning,
especially when fish return yearly for spawning at known locations.
The "no harvest" rule is implemented when a stock or species, for
example, Goliath Grouper (jewfish), is severely overfished. To
succeed, Florida's fisheries management strategies of size limits
and closed seasons depend on the survival of fish that are caught
and released. The fate of hook-and-line caught fishes that are
released largely depends on the expertise and dexterity of the
angler. Anglers practicing a few straightforward and intuitive
techniques can increase survival of released fishes.
"Limit your kill; don't kill your limit!"
After being caught and released by an angler, fish may die for a
variety of reasons. The most common causes of death are the
physiological stresses caused by the struggle during capture and
injuries caused by the hook or the angler. Some fish may die even
though they appear unharmed and despite efforts at revival. Fish
that struggle intensely for a long time during capture are usually
exhausted and stressed from the accumulation of excessive amounts
of lactic acid in their muscles and blood. Severe exhaustion causes
physiological imbalance, muscle failure, or death. Therefore, use
the proper weight-class tackle; land your catch quickly, and when
possible, leave the fish in the water while you release it. Any
exhausted animal needs oxygen to recover!
Hook wounds may appear minor to anglers, but damage to the
gills, eyes, or internal organs can be fatal. If the fish is hooked
deep in the throat or gut, research shows that it is best to cut
the leader at the hook and leave the hook in the fish. Prolonged
attempts to remove the hook often do more harm than good. In the
Fish and Wildlife Research Institute's (FWRI)* study of release
mortality in snook, 24 snook were deep hooked. We removed the hooks
from 12 snook, and we left the hook intact and cut the leader in
the other 12 snook. We found that four of the 12 deep-hooked snook
died after the hooks were removed. None died when we simply cut the
leader and left the hook alone. Fish are capable of rejecting,
expelling, or encapsulating hooks. Encapsulation is a process
whereby the fishes' healing process causes the hook to be covered
with an inert matrix of calcified material; or a-cellular tissue.
Steel and bronze hooks are less toxic and are rejected or
"dissolved" sooner than are stainless steel and cadmium-plated or
nickel-plated hooks.
Two types of hooks, barbless and circle hooks, are known to
reduce injury and mortality of released fishes. Barbless hooks
reduce tissue damage and handling stress because they can be
removed quickly and easily. Barbless hooks are popular in the
freshwater trout fisheries and are becoming increasingly popular
with saltwater anglers. A Florida study conducted on snappers and
groupers demonstrated that catch rates are the same for barbed and
barbless hooks. If barbless hooks are not available, simply use
pliers to crimp or remove the barbs from regular hooks. A caveat is
called for when using these types of hooks: after having hooked
your quarry, don't give the fish any slack, because it will be more
likely to escape from barbless hooks than from regular hooks.
The use of circle hooks has been researched and compared to
regular hooks-often called "J" hooks-in several fisheries. In all
of them except in the flatfish, or flounder, fishery, circle hooks
were shown to result in significantly lower hooking mortality and
higher catch rates. In one study, tunas and billfishes were hooked
in the jaw 90% of the time. Circle hooks reduced deep hooking
fourfold in the striped bass fishery while "J" hooks were 21 times
more likely to cause a bleeding injury. Circle hooks are a bit more
tedious to use, especially with live bait, but the advantages
should compel anglers to give them an honest trial. Overall,
research shows that circle hooks improve catch rates and reduce
hooking mortality which results in positive impacts on exploited
fish stocks.
Studies on striped bass, spotted seatrout, and snook have shown
that live bait was used in most cases of hook-related mortality and
that "gut hooking" was the primary cause of death. Artificial lures
are generally in motion, so the fish takes the bait and the hook is
set before the lure can be swallowed. To avoid internal damage from
gut hooking, when you use live or dead bait try to set the hook
immediately; with natural bait, there is less motion-the fishes'
immediate reaction is to swallow the bait. If you allow the fish to
run with the bait, the chances of gut hooking the fish
increase.
Survival rates for some Florida fishes
Controlled studies have shown that most fish released after
hook-and-line capture, survive. Researchers working in Boca Grande
Pass tagged 27 tarpon with sonic transmitters and found that 26 of
these hook-and-line-caught fish survived. The one fish that died
had been lifted from the water for a prerelease photograph.
Scientists repeatedly caught bonefish held in a large pond in the
Florida Keys and found that 96% survived capture. A few of the
bonefish that ultimately died had been caught five to ten times
each, which suggests that bonefish hooked and released in the wild
probably have an even higher survival rate. Angler-caught snook
held in large net-pens throughout Florida had a 98% survival rate.
Most of the snook that died were caught with live bait, consistent
with studies showing that fish caught with lures generally survive.
Spotted seatrout caught in Tampa Bay had a 95% survival rate. Hook
position affected survival rates; trout hooked in the gills or gut
had lower survival rates than those hooked in the mouth. Redfish
survival rates range from 84% in Georgia waters to 96% in Texas
waters. Like seatrout, hook position affected survival rates; more
than 50% of the throat or gut hooked fish died. These studies
demonstrate that catch-and-release-fishing works-most fish that are
released survive. By following a few simple guidelines, anglers can
maximize survival rates.
Venting distended gas bladders
Release of sublegal-sized groupers and snappers is imperative
because of increased minimum sizes and implementation of bag
limits. When these fishes are hauled from depths greater than about
30 feet, their air bladders become distended and many times cause
their stomachs to evert, or turn inside out, through their mouths.
Research is inconclusive regarding the benefits of venting
snappers. The uncertainty may be due to injury of internal organs
resulting from improper insertion of the venting tool into these
narrow-bodied fishes. In snappers, to avoid puncture of the heart,
liver, intestine, or gonad, it is crucial to insert the needle or
cannula just posterior to the tip of the pectoral fin. Groupers,
being wider bodied, better survive deflation, and venting has been
shown to positively increase their survival. The technique is the
same for both kinds of fishes.
The venting device should be a hollow needle no longer than 1½
inches with an inside diameter of about 1/8 inch or less, anything
much larger and you run the risk of improper healing or infection.
Puncture the body wall at the tip of the pectoral fin until you
hear the escape of trapped air. The angle should be about 60-75
degrees, which improves the ease of insertion. Do not insert the
needle too deep. If resistance is encountered, stop and try in a
slightly different location or angle. Leave the needle in place
until you are sure that most of the swelling or distension has been
relieved. Never puncture the stomach or try to force the stomach
back into the body. The fish will accomplish this better than we
ever could!
Small, narrow-bodied fishes such as porgies, grunts, angelfish,
and most snappers do well if they are simply returned to the water
as quickly as possible. A study conducted in the Florida Keys
showed that over 90% of individuals of these species are able to
return to the bottom without venting. Survival of groupers,
tilefish, and large snappers is increased when their distended gas
bladders are vented.
Some guidelines for catch-and-release
angling
The most important steps an angler can take to ensure a successful
release are to hook and land the fish as quickly as possible, leave
the fish in the water while removing the hook, and release the fish
quickly. There are several other ways to improve survival
rates:
- Whatever you do, do it quickly. Keeping an exhausted fish out
of water is like holding a bag over a runner who has just completed
a marathon. They both need oxygen to recuperate.
- Wet your hands or gloves before handling the fish. Do not
injure the eyes or gills. Placing the fish on a wet towel will help
the fish retain its protective slime. To keep the fish still, place
it on its back or cover its eyes with a wet towel. Control the fish
at all times! If you drop the fish, its chances of injury and death
increase.
- Decide beforehand which fish are to be kept; immediately
release all others. Do not engage in a prolonged debate over
whether or not to release the fish after the fish has been landed.
Never place a fish in your live well intending to release it later
if you catch a larger one. Once you make a decision to keep a fish,
stick with it. The fishes you release from your live well have a
decreased chance of survival.
- Avoid the use of gaffs, and never remove large fish such as
tarpon from the water. Large fish can injure themselves and the
crew and should, therefore, be treated with respect. Take a
photograph of the fish in the water and release it.
- Refrain from holding fish in a vertical position when
inspecting or photographing them. Internal organs are displaced and
stress is increased in this unnatural position. Large fish should
never be held by the bottom jaw only, with a boca grip or otherwise
(any tool designed to grip the lower jaw of caught fish to
facilitate handling). Hold the fish horizontally by the lower jaw
with one hand, and support the belly with the other hand. If
unsupported, many large fish, especially snook, will rupture the
isthmus-a cartilaginous bundle of ligaments that connects the head
and body--and the fish will die a slow death from starvation. This
connection is necessary for the tremendous gulping action during
feeding.
- If the hook is difficult to remove by hand, use long-nosed
pliers or a hook-removal tool. Do not tear additional tissue by
removing the hook. Back the hook through the original wound. If
this fails, cut the leader and pull the hook forward through the
injury. Regardless whether or not you intend to keep the fish cut
the leader close to the hook when releasing large Goliath Grouper
(jewfish), tarpon, sharks, and other fishes that are gut hooked. Do
not lift a gut-hooked fish out of the water by the leader; this can
increase damage to the fish.
- Try fishing with barbless hooks, or crimp and remove the barb.
Catch rates using barbed or barbless hooks are not significantly
different. Barbless hooks are easier to remove, and they cause less
physical damage to the fish.
- Use circle hooks. They cause less injury and increase catch
rates.
- If your fish is in good shape, immediately return it to the
water headfirst. If it does not swim or is lethargic or erratic,
some "resuscitation" may be needed until the fish can swim on its
own. Revive exhausted, but otherwise healthy fish by first placing
one hand under the tail and holding the bottom lip with the other.
If the fish is in fair to good shape, merely hold it headfirst into
the current. If it is severely lethargic, depress the bottom lip to
cause the jaw to gape and gently move the fish
forward. Moving the fish in an erratic back and forth motion will
just induce more stress. Have you ever seen a fish swim backward
and forward? At the first sign of the fish attempting to swim
away-let it go. Prolonged attempts at
resuscitation will be stressful to the fish.
- Large pelagic species such as sharks and tarpon should be
brought alongside the boat within 20 minutes of being hooked. If
you are consistently landing exhausted fish that require extensive
efforts at resuscitation, you should consider using heavier
tackle.
- To vent or not to vent? Several studies have been conducted to
determine if venting distended air bladders of fishes hauled from
deep water increases survival. It is inconclusive whether it is
beneficial to vent snappers; however, venting groupers has been
shown to positively increase survival. It is important to learn and
use proper procedures.
Practice and share these techniques! Teach your children and
inexperienced anglers these few simple procedures to help ensure
abundant fish populations for the future.
If you have any questions, please e-mail: ron.taylor@myfwc.com
* Formerly the Florida Marine Research Institute
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