Rockfish and Barotrauma

May 18, 2023

Question: About 20 years ago my husband took me on a rockfishing boat off the California coast where everything was provided for you. I was dismayed to see that many of the fish I brought up had stomachs bulging out of their mouths. I was informed this was likely fatal. Have recreational rockfishing practices improved?

Answer: We’re sorry your fishing experience left a negative impact. What you witnessed was a pressure related injury known as barotrauma. Rockfish have a specialized gas filled organ known as a swim bladder which allows them to control buoyancy and maintain depth in the water column by expanding and deflating the organ. Barotrauma occurs when a rockfish is unable to release expanding gases in the swim bladder as it is reeled to the surface.

Barotrauma injuries can cause the fish’s eyes, stomach, or vent to appear inflated. Although one might suspect the fish is dead, it is not. Due to the expanded gas trapped in their swim bladder from barotrauma, rockfish released at the surface are often too buoyant to swim back to the bottom. Impacts from barotrauma increase with the depth of the fish where you catch it.

Rockfish can be recompressed and recover from barotrauma if returned to the depth they were caught by using a descending device ( https://nrm.dfg.ca.gov/FileHandler.ashx?DocumentID=36345&inline ). Mortality is decreased when the fish is returned to appropriate depth as soon as possible, and the best way to minimize time on the surface is by using a descending device. Descending devices can be home-made out of simple items like wire hangers, weighted inverted milk crates, or purchased online and at tackle shops.

Over the years, the California Department of Fish and Wildlife (CDFW) has undertaken efforts to educate and encourage anglers to utilize ethical practices, which includes using descending devices when rockfish are released. You can learn more about barotrauma and the use of descending devices on CDFW’s Descending Device and Barotrauma web page ( https://wildlife.ca.gov/Conservation/Marine/Groundfish/Barotrauma ).

Twenty years ago, the science on barotrauma was not as well understood as it is today, and methods to mitigate barotrauma were not as commonly known. CDFW collects data on the use of descending devices in the field and is encouraged by recent efforts by charter and private vessels alike to return rockfish to the bottom rather than releasing at the surface.

For more information visit CDFW’s groundfish web page ( https://wildlife.ca.gov/Conservation/Marine/Groundfish).

I'm curious the impact that the new 300ft minimum depth will have on fish populations.

I'm curious the impact that the new 300ft minimum depth will have on fish populations.

I know it's not a cure, but I'm grateful the party boats have descenders.  I just wish they're require all of us to carry them with these new regs.

I can’t imagine that descenders really reverse deep barotrauma from 200’ or more. Seems like eye damage would be permanent. If I’m fishing deeper than 70’ and I feel a small fish on, I reel up slowly to let it adjust a bit. Seems to help.