Every day, many deep-dwelling fish die after being caught and released because their internal organs are damaged by the rapid pressure changes during the ascent to the surface.
The condition is similar to the bends, which scuba divers can experience when ascending too quickly.
But help is on the way: U.S. Commerce Secretary Wilbur Ross today granted final approval to a rule to help fish survive the pressure change. The rule, initially approved in September 2019 by the South Atlantic Fishery Management Council, requires snapper and grouper fishermen to carry special tools on board their boats that help the fish return to the depths. With final federal approval, the rule takes effect July 15, 2020.
The new rule requires recreational and commercial fishermen from North Carolina to eastern Florida to have ready-to-use descending devices on their boats. The weighted, reusable tools typically clip to a fish’s jaw and help it quickly return to its deep habitat. This improves chances that the fish’s internal organs, which would have expanded from harmful gases built up during the rapid ascent, will return to their normal size before they are irreparably damaged.
The condition, known as barotrauma, is killing millions of fish each year. The problem is so severe and widespread that it is affecting the overall health of some fish populations.
The rule requiring descending devices is a major conservation commitment that should help aid recovery of valuable fish populations such as red snapper. Reducing unnecessary deaths will lead to more robust fish populations—a win for fishermen, the U.S. marine ecosystem, and all who rely on healthy fisheries.
Fishermen often discard nontarget species and fish that are illegal to keep because they are too small, are out of season, or exceed a catch limit. Mortality of discarded fish is one of the biggest challenges facing many fish populations.
In the South Atlantic, a recent stock assessment found that 28.5% of recreationally caught red snapper die after release, which means that more than 460,000 red snapper perished after being thrown back in 2017. For commercially caught red snapper, the number is 38%, and some other species’ mortality rates are even higher. Another stock assessment reported that nearly all snowy grouper die after release, mainly because they are hauled up from very deep water.
The South Atlantic council developed a research and monitoring plan to improve understanding of the descending devices, track compliance, and incorporate the information in stock assessments. These steps should maximize use of the devices and measure how well the regulation helps fish populations recover.
Saving fish could lead to increased catch limits and more days when anglers and commercial fishermen are allowed to target some species.
Education efforts have increased fishermen’s awareness of barotrauma and the benefits of descending devices, which cost about $50 for a top-of-the-line model. For example, the National Oceanic and Atmospheric Administration’s Bycatch Reduction Engineering Program awarded $81,000 to the South Carolina Wildlife Federation to work with the South Atlantic council in educating fishermen about the tools, fish handling techniques, and best practices for releasing fish under a range of conditions and locations. The program provided nearly 500 free descending devices to anglers who completed an online tutorial or attended one of 13 educational workshops. And marine supply manufacturers, in partnership with state and federal fishery managers, are promoting best practices for releasing fish through the FishSmart Conservation Project.
Descending devices show strong promise in offering anglers a chance to help the fish populations they rely upon to recover, rebuild, and thrive.
Leda Cunningham and Lora Clarke lead Pew’s work in U.S. South Atlantic waters to protect and restore ocean resources and coastal habitats.