By Ron Lindner and Al Lindner with The Lindner Media Staff and Steve Quinn

No doubt about it; sportfishing today is facing a host of threats. They range in size from the tiny but invasive zooplankton creatures that threaten the underwater food web to the changes we see in the climate that encompass our whole earth. They include the simultaneous challenges of declining participation in fishing and increasing catch rates that threaten the quality of fisheries. Technology offers both its own threats as well as potential solutions.

Here we want to emphasize a threat that’s been present for a long time, but rarely have been recognized or acknowledged. It’s enmeshed with the highly popular practice of catch-and-release, which most fishery managers embrace as a boon to fish populations. But first some important history:

Catch and release has a long and hallowed history in North America. Back in the 1930s, trout anglers, including famous fly fisherman Lee Wulff, began to urge anglers to release legally harvestable trout they caught. He coined the phrase, “Gamefish are too valuable to be caught only once,” which became the rallying cry of catch-and-release proponents. They emphasized the idea of fishing for fun, rather than for food, the basis of the term “sport” in sportfishing. And they noted the benefits to fish populations when fish are released to grow and multiply.

In 1970, Muskies Inc. awarded their first “Release Trophy” to the angler who released the largest reported muskie, which went to famed muskie historian Larry Ramsell. The following year, Ron Lindner, owner of Lindy Tackle at the time, made a presentation at the annul Muskies Inc. meeting where he assisted organization founder Gil Hamm design their first “Catch and Release” logo and decal.

Over in the bass-fishing world, Ray Scott, founder of the Bass Anglers Sportsman Society (B. A. S. S.), staged his organization’s first catch-and-release competition in 1972 on Florida’s Kissimmee Chain of Lakes. While Scott cited conservation concerns, his primary goal was to quiet the many local critics who complained about these “pros” taking and killing too many of their fish. This first trial run employed crude aerator systems fashioned out of garden hoses, bilge pups, and plastic coolers. But by that fall, at the Bass Master Classic on Percy Priest Reservoir in Nashville, Tennessee, anglers fished from boats that had built-in livewells. Fledgling boat builder Forrest Wood supplied by his Ranger Boats for competitors and soon patented this feature.

The catch-and-release ethic grew rather rapidly in the trout, muskie, and bass realms, as fishery management agencies altered many harvest regulations to require mediate release of various length groups of fish, including minimum-length limits, which had been often applied on a statewide basis with little biological basis, maximum-length limits, and slot limits, including both protected slot lengths and harvest slot lengths. Fishing contests and award programs began to institute catch-and-release divisions, as Muskies Inc had done earlier. Bass clubs followed Ray Scott’s lead and used catch-and-release formats for their tournaments. A series of scientific symposia also were conducted during the 1980s and 1990s to report on the successes and pitfalls of catch-and-release programs and regulations, and to discuss further research needs.

In 1988, In-Fisherman started the Professional Walleye Tour (PWT), and they sought to include catch-and release formats in events. This move toward voluntarily releasing walleyes, widely regarded as among the tastiest of freshwater fish, met much greater resistance. When tournaments were held on Lake of the Woods and Lake Erie, where commercial fishing had been a large economic driver, we encountered resistance to this new philosophy. Though the Minnesota Department of Natural Resources had bought out all the commercial licenses on the Minnesota side of Lake of the Woods in 1985, commercial fishing remained a hot topic and tradition was on the side of the catch-and-keep crowd, though the department had established that commercial fishing wasn’t sustainable if sportfishing was to prosper there.

“When we were at a meeting in Cleveland to discuss catch-and-release, Al was threatened by a group of commercial fishermen,” Ron relates. “And In-Fisherman Editor-in-Chief Doug Stange and I were given a bad time in Baudette, Minnesota, on Lake of the Woods as well.” It came to be a dilemma whether commercial and recreational fishing for walleyes could coexist. And today, after a long battle, commercial walleye fishing is gone from American waters, resulting in excellent recreational fishing and great boost to local economies, in virtually all cases. And after years of stricter harvest restrictions on walleyes, including protected slot limits and harvest slots, many anglers have accepted the wisdom of releasing larger female walleyes to continue their spawning roles, while harvesting some smaller “keeper-size” fish.

In Manitoba, on the other hand, the battle between commercial and recreational fisherman rages on, with the province not seeking to place greater restrictions on this vast lake (9,500 square miles in area and 258 miles long). Lake Winnipeg also has been suffering from excessive eutrophication from phosphorous, and expansion of zebra mussels have further damaged water quality. Yet its fertility has boosted walleye growth rates, and it’s arguably the best lake for trophy walleyes, except for Lake Erie. This one will take a push from Manitoba anglers and nonresidents who spend money to fish there to start to say the balance. We shall see.

In-Fisherman Magazine popularized the concept of “Selective Harvest” in 1986, with a series of articles that highlighted the benefits and drawbacks of catch-and-release, which included delayed mortality and a shift away from using natural resources as food, which has been an American tradition for centuries, but has been eroded by a variety of causes. Editor-in-Chief Doug Stange described it this way: “The fish we catch and keep to eat are for most of us a reward for our effort that goes beyond sport and ties us to the principal reason that most of our ancestors fished. For them, fish as food was right up there with, and usually more important than, anything having to do with sport. Today, catching and then releasing fish so they can be caught again has become a vital part of fishing. In traditional fashion, however, most anglers still want to harvest at least some of their catch.

“Selective Harvest, an approach that captures the best aspects of “catch and release” angling, on one hand, and “catch and keep” angling, on the other. We suggest that anglers harvest fish selectively as a matter of conscience and conservation concern, and because fish are nutritious, delicious, and (when harvested selectively) a renewable resource. Anglers who practice selective harvest, where appropriate, let a portion of their catch go, particularly those large fish that are much less abundant than the smaller fish of the same species. They release 3-pound bass in favor of harvesting several 12-inch bass, the makings of a great meal. Or they take home a mess of abundant panfish of a medium-size, perhaps perch, bluegills, or crappies. This can help to sustain good fishing. Meanwhile, we also continue a tradition of eating some fish.”

Meanwhile, the major tournament circuit Major League Fishing, which includes the Professional Bass Tour, has used an immediate catch-weigh-release format since its inception in 2011. An impartial judge rides along to tabulate weights and report results electronically via a smartphone app. And the Angler Insight Marketing (AIM) walleye tournament circuit operates with a catch-record-release format, involving photographing the fish and a unique scorecard. These new catch-and-release formats mirror the Catch-Photo-Release version used by famed muskie angler Bob Mehsikomer.

Meanwhile over on the European continent, catch-and-release found a very different reception. Carp specialists in England were known to take the tenderest care of carp they caught, landing them in fine-mesh nets and holding them in “keep sacks” for measurement, even to the point of treating hook wounds with antiseptics before release to prevent infection. Yet in Germany a large faction opposed the practice of releasing fish alive, feeling that such “playing with fish” amounts to torture. This grew to the point that voluntarily releasing fish was banned in 1998. The German Animal Welfare Act states that, “no one may cause an animal pain, suffering, or harm without good reason.” Thus caught fish must be kept and eaten, as fishing for fun is not regarded as a “good reason.” Switzerland joined this front in 2009, mandating that no one pursue fish with the “intent” to release them after capture. Now, it seems that other European Union countries may be considering similar statutes.

In Europe and here in the U.S., animal rights activists, most notably People for the Ethical Treatment of Animals (P. E. T. A.) and the Humane Society of the Unites States (H. S. U. S.) have created campaigns to lobby against recreational fishing, which have often been targeted toward impressionable youth, and performed under the watchful eye of the national press. Their efforts have ebbed and waned over the decades of their activities, and public polls suggest they have not made substantial headway in changing the positive outlook of Americans toward sportfishing. In recent years, they have ben less in evidence.


These previous challenges to catch-and-release pale in comparison, however, to one that anglers and fishery managers have been aware of for many years, but generally chosen to “sweep under the rug.” That’s the growing problem of barotrauma, meaning the physiological damage to fish that are caught in excessively deep water.

Ron relates a story from 40 years ago around Morson on Lake of the Woods. Using vintage sonars, he and Al had found groups of crappies suspended in what is now known as a classic late-fall pattern, about 30 feet down over 45 feet or so. “We were catching them one after the other,” Ron says, ”and releasing these big slabs, 13 to 15 inches. We started looking around and I said to Al, ‘We got a problem.’ Fish were floating all around the boat, just struggling on the surface.” This lesson was reinforced a few years later while they were fishing in Florida for snapper. Those schools were in 60 to 70 feet and when they came up, their stomachs were protruding from their mouths, and some had bulging eyes. They struggled to swim down, but most floated off into oblivion.

Back in 1989, In-Fisherman contributor and fishery scientist Ralph Manns wrote the first in-depth article pointing out the problems of barotrauma, and calling for anglers and fishery management agencies to address concerns before the situation got worse. Unfortunately, little heed was paid to the problem in the freshwater realm, except for tournament anglers fishing the Great Lakes and other deepwater habitats for walleyes and smallmouth bass who learned how to “fizz” fish caught from deep water (generally over 30 feet deep) using a hypodermic needle. Correctly inserting the needle into the gas bladder allowed air bubbles to escape from that organ, allowing the fish to swim back down. While physiological studies showed that the gas bladder healed rather quickly, problems arose from anglers sticking needles the wrong locations, paralyzing fish or damaging their livers. As a result, some state agencies discouraged or even banned “fizzing,” while others continued to allow or even recommend it.

The problem afflicts fish species that do not have a duct structure (called the pneumatic duct) between the gas bladder and the alimentary canal, which allows expanding air to escape. Due to the laws of physics, pressure is doubled at 33 feet of depth, compared to sea level, theoretically doubling the volume required to hold it. Because the gas bladder is a rather elastic organ, it resists stretching, but gradually succumbs to drastic changes in pressure and expands, often preventing fish from swimming back down. While immediate release from moderate depths (20 to 40 feet) typically causes no problems with bass and walleyes), holding the fish at the surface for several minutes increases barotrauma problems. And storing a fish in a livewell for hours can cause severe symptoms in fish caught in 20 to 30 feet of water.

Species lacking this duct (including walleyes, bass, crappies, perch, and white bass) require substantial time to adjust pressure levels when shifting depths. Species with ducts, including catfish, sturgeon, salmon, and trout, carp, and shad, can release air immediately, thus are generally capable of greater vertical mobility. You see this in action when big lake trout, sturgeon, or catfish release air and create large bubbles as they near the surface. And they can generally swim straight back down, even from depths over 100 feet. At greater depths, physiological damage can occur, including hemorrhaging, exophthalmia (eyes popped out of their sockets), and tissue damage as bubbles form and expand in organs or the blood stream. This most often occurs in marine situations, where fish often are targeted deeper than 100 feet. Valuable species such as groupers, snappers, and rockfish lack ducts and are at great risk of post-release mortality.

Given the economic value of recreational saltwater fishing, and the heavy fishing pressure on popular species that’s caused widespread overharvest, marine fishery managers have been way ahead of their inland colleagues in studying and addressing this problem. In October 2019, the South Atlantic Fishery Management Council made a landmark decision by mandating that all commercial and recreational fishermen who are targeting grouper or snapper must have a descending device readily available on boar to release fish. A variety of these devices have been on the market for several years. Some, such as SeaQualizer and RokLees Fish Descender, clip on the jaw of a fish, and carry it back into the depths, reducing gas pressure in the descending process. Back down where it was caught, the device releases the fish or can be triggered to pop open, leaving the fish in good condition, as long as no other damage had been done. Other devices function like cages with a trap door that carry fish back down and the door releases at the appropriate depth.

This decision by the Management Council followed findings by scientists with the National Oceanic and Atmospheric Association (NOAA) that almost 30 percent of all snapper and almost 40 percent of grouper caught by recreational anglers died after release, obviously an unacceptable level of post-release mortality. They found that unwanted fish released improperly was one of the largest problems facing marine fishery managers in recent years. The following month, a bipartisan group of U.S. congressman introduced “The DESCEND Act of 2019” requiring commercial and recreational fishermen to possess a descending device rigged and ready for use or a venting tool (needle used for “fizzing”) when fishing for reef fish in the Gulf of Mexico. This proposed legislation was praised by a group of fishing and boating organizations, including the American Sportfishing Association (ASA), Coastal Conservation Association (CCA), and the Congressional Sportsman’s Foundation CSF).

In the freshwater realm, anglers have been exploiting deep fish aggregations, aided by hi-tech sonar units that depict fish, and can even define species, at great range and with amazing clarity. At recent major bass tournaments on the St. Lawrence River, on the border of New York and Canada, pros located groups of huge smallmouths deeper than 40 feet. Several pros later reported being shocked to see the many dead trophy-size smallmouths floating near the weigh-in site in New York, victims of barotrauma. In other areas with deep reservoirs such as the Southeast and West, anglers often target bass and walleyes in water deeper than 30 feet, waters where minimum-length limits often are in place. Such limits may thus mandate the release and waste of fish caught from great depths.

Ice anglers have discovered the deep-water winter haunts of walleyes and crappies, often pulling fish from more than 30 feet. As Ron and Al observed years ago in Canada, crappies are particularly vulnerable to even mild barotrauma, sometimes having difficulty swimming back down when caught and quickly released in less than 25 feet of water. Anglers with underwater cameras have reported popular fishing areas littered with the carcasses of fish that were released and did not make it, primarilly due to barotrauma.

With this article, we seek to inspire action by angler organizations, fishery management agencies, and individual anglers to address this growing problem head-on. We must document the extent of delayed mortality in enough cases to generalize across many more waterways, and put potential solutions on the table. Ignoring this problem any longer only serves to perpetuate bad habits and further damage the fisheries we love and depend on for our recreation and livelihood.

Let’s not forget that angler opportunity and healthy fish populations are not only vitally important to millions of anglers, they represent a huge economic engine. According to the latest statistics, America’s anglers are estimated to spend $49.8 billion per year in retail sales associated with fishing. With a total annual economic impact of $125 billion, fishing supports more than 800,000 jobs and generates $38 billion in wages and $16 billion in federal, state and local taxes.

It’s important to keep the momentum and continue to promote sustainable recreational fishing. In this effort we need to further address the challenges presented by barotrauma to fishery management and healthy fish stocks. As we noted earlier, marine fishery managers have been far more responsive to this issue, and we’ve seen new legislation to promote use of descending devices. In the freshwater realm, we need to take a harder look at this problem, investigating problems of excessive mortality to discarded moribund fish in open-water and ice-fishing settings.

Addressing these problems also prevents anti-fishing forces from gaining further ammunition in their quest to limit or even ban fishing, as well as hunting and trapping, as has occurred to our angling brethren in Germany and other parts of Europe. Though their propaganda against recreational fishihg appears to have somewhat subsided in the public sector, they have tried to use the educational system to promote their philosophy. Limiting these efforts its essential as we move forward.

When Releasing Deep-water Fish, the Right Tools Mean Everything