Editor's note: This story has been updated to correct the fact that nonpelagic rockfish experience barotrauma no matter how fast they are reeled up by anglers.
As more anglers begin to pull up yelloweye rockfish and other nonpelagic rockfish, fisheries managers want to encourage them to use devices to release them at depth to conserve the fish populations.
Nonpelagic rockfish live near the ocean floor in rocky habitats along the Gulf of Alaska coast, typically at depths of 300–600 feet, according to the Alaska Department of Fish and Game. They’re typically long-lived, between 15 and 75 years old.
They also put up a good fight and provide tasty eating, which makes them popular for sportfishing. The regulations on bag limits vary from area to area, so anglers may release fish until they’re ready to quit fishing. However, releasing nonpelagic rockfish the same way one releases a salmon doesn’t really work — the fish are likely to die on the surface.
When anglers reel up a rockfish, the fish experience barotrauma — decompression sickness, or what divers call the bends. This leads to physical damage such as their swim bladders inflating out and their eyes popping out, among other consequences, said Jay Baumer, the area management biologist for the Division of Sport Fish on the North Gulf Coast and in Prince William Sound.
“It’s really hard for us to pinpoint one thing on a fish that is going to cause issues for them,” he said. “Really, it’s a collective, because of all the changes in pressure. Their swim bladder sticking out, their eyes popping out … the collective of those will provide issues for the fish.”
When the fish can’t resubmerge, the pressure won’t normalize and the fish will be stuck on the surface with the damage of decompression, and they’ll be vulnerable to seabird predation. Fish and Game studies have estimated that survival rates for normal surface releases are about 20 percent.
However, some anglers and guides began using devices basically as sinkers to take the fish back to depth before releasing them. There are a variety of types, ranging from a modified lead head jig to more expensive deepwater release-specific devices. Several studies have shown that when yelloweye rockfish are lowered back down, their survival rates skyrocket from about 20 percent to more than 90 percent.
It’s hard to say exactly how many nonpelagic rockfish there are in areas like Prince William Sound or Resurrection Bay, though there have been surveys in Southeast and Kodiak, Baumer said. Fish and Game is working on survey methods to help evaluate the nonpelagic rockfish populations there, but resources to conduct extra research are limited, he said.
In Southeast Alaska, charter boat guides have been required to have deepwater release devices on board since 2012. At the most recent Board of Fisheries meeting in Sitka, the board passed new proposal requiring all saltwater sport anglers in Southeast Alaska to have deepwater release devices on board by the 2020 season. At the upcoming statewide meeting from March 6–9, the board will consider a proposal requiring the devices for all marine sport anglers to use the devices releasing the fish to at least 100 feet.
The Kenai and Soldotna Fish and Game Advisory Committee at its Jan. 11 meeting recommended supporting the concept of all anglers using deepwater release devices. Chairman Mike Crawford said there’s a learning curve to using the devices but that with the survival rates so much higher, it is worthwhile.
Baumer said the main concern in high mortality in the population of nonpelagic rockfish is that because they are so long-lived, it may be hard for the populations to stay stable when anglers are removing many of them, especially the largest. When not retaining them, it’s hard to say exactly how long they can survive but it’s best to move fast, he said. Many anglers keep a separate pole with the deepwater release device already set up on their boat specifically for that purpose to save time.
“Just like any other fish, when you hold them out of the water, they are not breathing,” he said. “The sooner you can return them to the water and sooner you can get them back down to depth, the better.”
The Division of Sport Fish supports the use of deepwater release devices, but prefers to do it through education rather than regulation, said Sportfish Director Tom Brookover at the Board of Fisheries meeting in Sitka.
“People are generally supportive,” he said. “The question is how much and how fast can that move through education and outreach.”
Fish and Game includes information about deepwater release in its sport fish regulation summary book and is planning to do more outreach about the practice this year, said Division of Sport Fish Public Information Officer Ryan Ragan. The department is planning to give away some of the release devices for free at the upcoming Great Alaska Sportsman’s Show in Anchorage and at the Kenai Peninsula Sport, Rec and Trade Show in Soldotna in April.
“All they have to do is provide us with a little basic contact information … and then they get a device, they go out and while they’re fishing hopefully they use it if they’re releasing rockfish,” he said. “Part of the reason why we’re collecting some of that information is that later in the year, maybe even toward the end of the season, we’ll probably email them a small survey to find out if they used the device and how much.”
Fish and Game is also working on new informational signs about deepwater release to hang around ports in Southcentral and Southeast Alaska to promote the practice. Anyone who has questions is welcome to call the Division of Sport Fish Information Center in Anchorage, he said.
Reach Elizabeth Earl at firstname.lastname@example.org.