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Bring That Rockfish Down

WHY ARE ROCKFISH PRONE TO
ROCKFISH-BAROTRAUMA MYTHS
PRESSURE-RELATED INJURIES?
Myth:
Reeling a fish in slowly prevents barotrauma.
Every rockfish has a gas-filled organ called a swim
Fact:
Rockfish cannot acclimate to the pressure drop
bladder that allows the fish to gently control its
even when reeled in slowly.
buoyancy. By deflating its bladder, a fish can descend
more easily. By inflating it, its ascent is assisted. When a
Myth:
The organ protruding from a “popped” fish’s
fish is caught and reeled in, this mechanism for moving
mouth is the swim bladder.
vertically in the water column is thrown out of whack.
Fact:
It is the stomach! Never vent the stomach or try
Depending on the depth at which the fish was caught, a
to force it back inside the mouth.
fish’s air bladder may swell so much its stomach is forced
out its mouth. The eyes may bulge and other organs can
Myth:
You can tell by looking whether a fish will survive
be injured as well. Fish suffering from pressure-related
or die.
injuries are said to be experiencing barotrauma (pressure
Fact:
When properly recompressed, even fish with
shock). Without intervention, a fish with barotrauma
severe barotrauma can survive.
may die from the progression of its wounds or succumb
to temperature shock or predators.
“Floaters” – overly inflated fish that cannot re-descend
ROCKFISH-BAROTRAUMA
on their own – are especially easy targets for sea gulls and
sea lions.
SCIENCE
According to published results of a Sea Grant
study led by researchers at Cal State Long Beach:
The degree of barotrauma in a fish is not a reliable
predictor of its survival. The most significant predictor
of post-release survivorship is the time a fish spends at
the surface.
In experiments with several species of common
Southern California rockfish, 83 percent of fish caught
at depths between 217 feet and 350 feet, survived when
returned to depth within 2 minutes. The odds of a fish
dying following recompression nearly doubled with
every 10-minute increase in time at the surface.
Tagging and recapture studies showed some released
fish were still alive 1.5 years later.
For current recreational groundfish fishing regulations,
The volume of a fish’s swim bladder can triple when reeled in from
call (831) 649-2801 for recorded information or visit the
depths as shal ow as 60 feet.
California Department of Fish and Game website at
www.dfg.ca.gov/marine/regulations.asp.
BRING THAT
ROCKFISH
Alternate communication formats of this document are available
upon request. If reasonable accomodation is needed, call DFG at
This brochure was a collaborative effort of California Sea Grant, Oregon Sea Grant
DOWN
(916) 322-8911. The California Relay Service for the deaf or hearing-
and University of Southern California Sea Grant.
impaired can be utilized from TDD phones at (800) 735-2929.
Printing was funded by the California Department of Fish and Game.
FISH CAN SURVIVE BAROTRAUMA
PRACTICE THE FOLLOWING
Amazingly, rockfish that look dead at the surface can
TECHNIQUES AND
“pop” back to life if quickly returned to a native depth
SAVE ROCKFISH LIKE THIS!
range. Because of this, rockfish that you must, or want
to, toss back should be quickly recompressed.
Inverted barbless hook with weight
Inverted barbless hook with weight: Hook fish through
lower lip from inside to outside, to keep hook from
puncturing an extruded stomach and to prevent line cuts
to eyes. You can also hook a fish through the membrane
on its upper lip from outside to inside, which some say
Even fish with bulging eyes and protruding stomach can survive if
There are many ways of returning a fish to a depth at which
makes for easier release. In both cases, the weight must
returned to depth quickly. Note: the organ protruding from the fish’s
mouth is the stomach, not the swim bladder.
it can recompress. Your choice may depend on the size of the
lead the fish into the water and be heavy enough to sink it
fish you usually catch, your experience as an angler, sea
to the desired depth. Fish is released with a sharp jerk on
conditions and cost.
the line. Caveats: Hook can puncture an extruded
TOP FIVE REASONS TO
stomach. Once a fish reaches a depth at which it regains
SEND’EM DOWN
muscle coordination, it may wrestle free prematurely.
Method works best with smaller fish.
Why should you care about helping a released fish
return to depth?
1. Floating fish are a waste of the resource.
2. Some populations of prohibited species, such as
canary and yelloweye rockfish, may take decades to
rebuild.
3. High-grading is illegal and selects for smaller fish in
Upside-down crate, weighted and at ached to rope
the gene pool.
4. Venting fish may cause more harm than good.
Upside-down milk crate, weighted and attached to a rope:
Commercial fish descender
5. Re-descending fish can increase their chances of
Crate is dropped over the fish and then, with the buoyant fish
survival.
inside, lowered to a minimum depth of 60 feet and kept down
Commercial fish descenders: There are a variety of practical,
Catch-and-release practices work best when you
until it can swim out on its own. Caveats: In rough seas, fish
easy-to-use fish descenders on the market. The best one for
can help with fish survival. Helping fish get back
can escape prematurely and the crate may bang against a fish’s
you may depend on the sizes and species you catch. For more
down is good for the resource and the sport.
extended eyes. Try lowering the fish down gently or paint
crate’s inside with a rubberized coating to smooth sharp edges.
information, visit www.sheltonproducts.com and
http://git-r-down.com.
VENTING: A sharp needle or steel cannula is used to puncture a fish’s inflated swim bladder.
The California Department of Fish and Game does not currently encourage venting as it can cause
serious injury to fish and angler. You may accidentally puncture the wrong organ and/or introduce
infection. Even when done properly, venting damages a fish’s swim bladder.