|On the Water: Fish Report|
|Written by Larry Ellis, fishing columnist|
|June 07, 2013 07:30 pm|
Its eyes, which are normally sunk deep inside of its head, look like they are about ready to pop out of their sockets. In addition, extending out of its mouth is a red tube-like structure that resembles a bizarre party balloon.
If you ever witness this type of sea creature and wish to release it, do not attempt to pop the balloon with a hook or a needle. Doing so would be deemed a form of fish abuse.
The fish is actually experiencing what scientists call barotrauma, also known as PTSD, or, Post Traumatic Stretch Disorder.
In reality, the fish has a severe case of the bends.
All rockfish possess a gas-filled swim bladder, an organ that they use to self-regulate their buoyancy. When a fish is in deep water, the gas in its swim bladder is compressed, and the swim bladder is self-maintained at its normal size.
But when a fish is brought to the surface by a fisherman, the fish non-voluntarily decompresses, and rapidly-expanding gas inside the swim bladder causes the swim bladder to stretch and expand. How much it expands depends on how deep the fish was caught.
If the fish was only caught in 60 feet of water, it might look like it’s only sticking out its tongue. But if it has been brought up from 90 feet or more, it looks like it is puking its guts out.
And that’s exactly what it’s doing. The stretched-out swim bladder is pressing so tightly against the fish’s stomach, it actually squeezes the stomach out of the fish’s mouth, what’s referred to as an everted stomach.
Many people think that the balloon-like organ sticking out of the fish’s mouth is its swim bladder, so on occasion, they’ll stick the organ with a sharp object, thinking that they’re actually relieving the pressure in its swim bladder. Even though puncturing a fish’s stomach might at first glance appear to revive the fish somewhat, doing so will eventually kill the fish. How would you feel if somebody lanced your stomach?
To save the fish, the answer is to get the fish back down to its original catch depth as quickly as possible by using a recompression device.
When a rockfish is sent back to its home in this manner, the swim bladder recompresses and returns to normal size. Its once-bulging eyes are sucked back into its sockets, and its extended stomach is withdrawn back into its proper place in the fish’s abdomen.
In a meeting held in the Chetco Community Public Library last Wednesday, Lynn Mattess, ODFW’s Sport Groundfish Project Leader gave a presentation on barotrauma to about 30 attendees. Assisting in the presentation was Assistant Groundfish Project Leader Patrick Mirick.
Mattes showed a video demonstrating how everted eyes and stomachs of rockfish returned back to their normal places in their bodies after the fish is recompressed. To see an amazing video of a yelloweye rockfish being recompressed, and its everted eyes and stomachs retracting, visit www.dfw.state.or.us/MRP/research/.
Anglers are being encouraged to use recompression devices to get rockfish back down to their original catch depth. Mirick said that by simply using a couple hundred feet of tuna cord, and a sinker weighing between 2 and 3 pounds, a myriad of recompression devices can be used, with the least expensive appliance being the Shelton Fish Descender ($5.49).
So why should everyone have a recompression device on board their boat? The answer is so that we will be able to continue fishing for rockfish and lingcod the entire year.
The most commonly-caught fish on the Oregon coast is the black rockfish, and our quotas for blacks, other species of rockfish, and lingcod, are directly related to the bi-catch mortality of yelloweye and canary rockfish. Bi-catch refers to incidentally-caught yelloweye and canary rockfish. By law, we are required to release all yelloweye or canary rockfish. But if you’re not using a recompression device, ODFW counts all those fish as being dead.
Once the bi-catch harvest cap for yelloweye and canary rockfish is attained, we will be forced to stop fishing for the rest of the year.
“We’re now getting credit for releasing yelloweye and canary rockfish using these release devices,” says local PFMC representative Richard Heap.
Everyone is now starting to catch a lot more canary rockfish. One of the questions that ODFW port samplers asks everyone is if they are using a recompression device to release their canaries and/or yelloweyes. If your answer is no, you’re ruining the rockfish fishery. So be a responsible steward for our fishery. Carry a recompression release device on board your boat.