Stripers for the Future
Employing Best Practices to Increase the Survival of Released Striped Bass
Issue: January 2013,
New Jersey and New York anglers are fortunate to live in the heart of the striper coast. Striped bass are found in the region’s coastal waters throughout much of the year, but fishing really heats up during the spring and fall migration runs.
In complying with current regulations, New Jersey anglers can harvest two fish per day with a minimum size of 28 inches and an additional fish at a minimum size of 28 inches if a bonus permit is obtained from the Division of Fish and Wildlife. Anglers fishing in marine waters of New York can harvest one striper per day between 28 and 40 inches and a second fish over 40 inches. Striped bass that do not meet these criteria for harvest must be released. In addition, many anglers voluntarily practice catch and release of striped bass. As a result, the magnitude of striped bass catch and release in our region is substantial. In 2011, the National Marine Fisheries Service (NMFS) estimated that over 880,000 stripers were released by New Jersey anglers. That same year, New York anglers released close to 1.5 million stripers!
Practicing catch-and-release allows anglers to contribute to the long-term sustainability of this important fishery. However, despite the best intentions of anglers practicing catch and release, stripers experience physiological stress and potentially physical injury during capture and handling. Depending on the degree of these impacts, it may take some time to recover from being caught, altering post-release behavior and potentially resulting in mortality.
The potential mortality rate of striped bass following release is not trivial. The Atlantic States Marine Fisheries Commission (ASMFC) management plan currently assumes an 8 percent hooking mortality rate for striped bass caught and released by recreational anglers in the marine environment. Applying this mortality rate to 2011 NMFS release statistics for New Jersey and New York yields an estimate of over 192,000 dead stripers! A substantial portion of this mortality is likely due to a lack of understanding among anglers regarding how their angling techniques can physically injure and physiologically stress fish. Many anglers assume that seeing a fish swim away means that it will survive to be caught again, however this may not be the case.
Causes of Stress in Angled Striped Bass
It is all about choices we make during each step of an angling event—the capture, handling, and release.
Choice of terminal tackle happens even before a fish is caught. Terminal tackle type, including the number and style of hooks and type of bait, can affect how a striper is hooked. The location of hook wounds has been found to be one of the most important factors influencing survival rates for released striped bass, with mortality being highest if the hook-up results in injury to a vital organ. For example, a fish hooked in the jaw stands a much better chance of survival than a fish that is hooked in the gills, throat, or stomach. Being hooked in these sensitive locations increases the risk of injury during angling and also when hooks are removed.
Deep hooking is one of the most frequent causes of death for an angled striped bass. Swallowed hooks induce trauma during the initial hook penetration and subsequent playing time, as well as angler-induced trauma during hook removal. Research has shown that the odds of death for gut-hooked fish are almost six times the odds of death for fish hooked in the lip. Gut-hooking is often higher with live baits or natural baits than with artificial baits since fish often swallow baited hooks more deeply.
Many anglers use J-style hooks when fishing for striped bass with bait, perhaps unaware that these hooks facilitate swallowing of the terminal gear resulting in gut hooking. Non-offset circle hooks provide a less lethal option for anglers bait-fishing for striped bass. The unique shape and hook point location of circle hooks causes minimal damage, reduces the chance of lethal wounding, and makes it easier to unhook and quickly release fish. When a fish takes bait fished on a circle hook and continues to swim or make a turn, the hook pulls until the point catches the fish in the corner of the mouth. Even if a circle hook is swallowed, it will usually slide out of the stomach when the fish moves off with the bait. As the leader is pulled through the fish’s mouth, it guides the circle hook around the jaw where it locks in place.
Many studies have reported lower injury and mortality in striped bass when fish are angled with artificial baits since lures generally hook stripers in the jaw or mouth. However, lures can also present problems. For example, large plugs rigged with multiple treble hooks can cause injury to a striper since the free hooks often swing around and catch in the fish’s gills or eyes. Treble hooks may also require an inordinate amount of time for removal, prolonging air exposure prior to release.
To counter these impacts, it is often recommended that anglers replace treble hooks on plugs and metal lures with single hooks. The International Game Fish Association recently endorsed the idea of replacing treble hooks on crankbaits, lipped plugs, topwater lures, and spoons with single hooks to facilitate easier de-hooking and faster release of fish. However, even single hooks can cause problems with hook removal if they are barbed hooks. Crushing hook barbs or using barbless hooks on plugs and lures reduces hooking injuries and facilitates easy hook removal and reduced handling time.
Once hooked up, fighting on the end of the fishing line is extreme exercise for a striper. Fish that struggle intensely for prolonged periods of time during angling become exhausted. As fish fight, lactic acid builds up because of extreme muscle function. Increased levels of lactic acid can lead to a situation known as acidosis and exhausted fish may reach a point that results in muscle fatigue that impacts swimming and behavior following release. If a predator is around following release, this could be bad news for the fish. Alternatively, recovering from angling-induced exercise can interfere with the ability to chase prey or migrate, influencing the normal habits of a striped bass. To reduce stress related to exercise, try not to play a fish to exhaustion. Match the tackle to your anticipated catch, and get that fish in as quickly as possible.
Once landed, handling and air exposure can have considerable impacts on the fate of fish following release. For example, striped bass have a protective mucous layer that prevents disease and infection from entering through their skin. The more a fish is handled, the more of this protective slime that is removed, and this may compromise the fish’s ability to fight off diseases and parasites. As for air exposure, a fish’s gills are not designed to extract oxygen from air. As such, it is additionally stressful if a striper is exposed to air for hook removal or a picture especially after fighting at the end of a fishing line.
Other things to consider are the potential impacts of water temperature. As water temperatures rise, a fish’s metabolism increases, as likely does the stresses imposed by angling. If the water temperatures are increasing, take extra precautions to reduce fight and handling times. Another thing to consider is where you are fishing. Research has shown that angling stress is greater for striped bass in freshwater than in marine waters. This is an important consideration for anglers fishing in low salinity areas such as the upper portions of estuaries, as stripers in these habitats are more likely to experience greater stress during catch-and-release than bass taken in higher salinity waters.
As a conservation-minded angler, the goal is to use best practices for catch-and-release that reduce stress and minimize injury to striped bass.
Best Practices: Suggestions to Boost Survival Rates of Released Striped Bass
• Always use appropriate weight-class tackle that allows stripers to be brought in quickly to reduce exhaustion and minimize stress.
• When fishing with plugs and lures with multiple treble hooks, consider removing one or two sets of hooks or replacing them with single hooks.
• In general, use single barbless hooks whenever possible, or crimp, file or flatten the barbs on hooks to ease hook removal and reduce tissue damage and handling stress.
• When fishing with natural or live bait, use non-offset circle hooks to minimize gut hooking and the chance of lethal wounding of striped bass to be released. (Note that octopus-style hooks are not true circle hooks and fish like traditional J-hooks.)
• When using the “snag and drop” technique to snag menhaden, herring or other live bait on treble hooks, transfer and swim baits on a single circle hook rig.
• When you feel a strike, set the hook quickly to prevent the fish from taking the hook deep in its throat or stomach where it may cause internal organ damage and be hard or impossible to remove.
• Once a fish is hooked, land it quickly rather than playing it to exhaustion. A fish brought to the boat or shore quickly has a much better chance of survival after release than one that has been exhausted by a lengthy fight.
• Ideally, do not take the fish out of the water. Striped bass should be unhooked quickly and carefully in the water to reduce stress and the potential for injury, especially when air temperature is much higher than water temperature.
• If a fish must be removed from the water, always try to minimize the amount of time it is kept out of the water, handle the fish as little as possible, and release it quickly.
• Avoid using gaffs to land striped bass that are going to be released. In a jetty situation, if a gaff must be used, gaff fish in the jaw or corner of the mouth only.
• When using a landing net, use a net with small mesh made out of rubber, knotless nylon, or other soft non-abrasive material rather than a large mesh polypropylene net. These materials remove less slime and reduce potential wounding. Make sure the net basket is shallow and of sufficient circumference so it doesn’t bend the fish.
• If you need to lift a striped bass, refrain from holding them in a vertical position to avoid displacing or stressing internal organs. Hold fish horizontally by firmly gripping the lower jaw with one hand and gently supporting its weight under the belly with the palm of the other hand.
• Once a striper is landed, keep it from thrashing around and injuring itself.
• When unhooking a striped bass, handle fish carefully using wet hands, wet cotton gloves or a wet towel to minimize removal of the fish’s protective mucous layer.
• Avoid touching or injuring the eyes.
• Avoid touching the gills, as this could damage the gills and impair the fish’s ability to breathe.
• If a fish is deep hooked in the esophagus or gut, cut the leader as close as you can to the hook and leave the hook in the fish—attempting to dig the hook out can cause considerable trauma.
• If a hook is difficult to remove by hand, use a de-hooking tool such as long-nosed pliers, hemostats (forceps) or a commercially available hook removal tool.
• Fish in good condition should be quickly and gently returned to the water in an upright, horizontal position. Fish that are stressed by the fight or handling and unhooking should be revived prior to release.
• Revive exhausted fish by holding them headfirst into the current or direction of the seas in the swimming position with one hand under the tail and the other under the fish’s belly by grasping its jaw between your thumb and forefinger.
• Gently move fish in a figure-8 pattern to get water flowing through the mouth and over the gills. Always keep the fish moving forward; never move the fish backwards.
• When the fish is revived, let it swim away on its own. Do not let the fish go until it clamps down on your thumb or is able to swim strongly and freely out of your grasp.
It is our hope that the information contained in this article will allow anglers to better understand the causes of stress in angled striped bass. By using best catch-and-release practices, anglers can ensure greater chances of survival of released fish and increase their contributions to conservation of this important recreational species.
John Tiedemann is the Assistant Dean in the Monmouth University School of Science and Director of the Marine and Environmental Biology and Policy Program. A lifelong resident of New Jersey, he has spent his career working on marine and environmental issues affecting the state’s coastal zone. When not at work he can be found fishing or surfing along New Jersey’s northern coast.
Dr. Andy Danylchuk is an Assistant Professor of Fish Conservation at the University of Massachusetts Amherst. Andy grew up fishing and has steered his career so that he can help conserve recreational fish stocks for future generations to enjoy. His work has focused on bonefish, great barracuda, sharks, sea-run brown trout, and striped bass.
This article is the result of research sponsored by the New Jersey Sea Grant Consortium with funds from the National Oceanic and Atmospheric Administration (NOAA) Office of Sea Grant, U.S. Department of Commerce, under NOAA grant number NA10OAR4170075 and the NJSGC. The statements, findings, conclusions, and recommendations are those of the author(s) and do not necessarily reflect the views of the NJSGC or the U.S Department of Commerce.