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FINSIGHTS- TRANSLATING THE SCIENCE OF FISHERIES REPORTS #10

Finsights #10 Lip gripping devices and your catch. Tiger fish. Dave McCoy photo.

Finsights #10 Lip gripping devices and your catch. Tiger fish. Dave McCoy photo.

Sport Fishing Magazine recently published an article on A Guide to Lip Grippers. The very last paragraph of the article touches on how lip gripping devices can impact fish and the author states “Many of the lip-grip manufacturers interviewed independently stated that they believe their weight scales do not cause physical damage to fish or inhibit future feeding ability — when the fish is hung vertically”.  I decided to dig through the scientific literature to see if anyone had looked at this at this and found only three studies that focused on lip gripping devices, each on different species.

 
Bonefish The first study looked at if lip-gripping devices caused injury to bonefish.  They compared bonefish held vertically in the air with a lip gripper to those held horizontally in the water with a lip gripper, all compared against a ‘control group’ where bonefish were handled only with bare hands   Bonefish held with a lip-griping device either vertically or horizontally were prone to injury – 90% of fish had at least minor injuries (which included holes through the tissue of the lower jaw where the lip gripping device was placed) and 35% of fish had major injuries (including broken mandible and separated tongue).  Conversely, only one of the fish held by hand had a minor injury and none had major injuries.  All fish survived for 48 hours after being handled, but the authors did not monitor for long-term survival or feeding ability.  

Injuries sustained to bonefish using a mechanical lip-gripping device.  Link to report.

Injuries sustained to bonefish using a mechanical lip-gripping device. Link to report.


Barramundi In 2009, a different group of scientists looked at how lip grippers compared to nets for holding barramundi (an Australian sportfish).  They compared barramundi held in a net with those held vertically by a lip gripper, as well as those held horizontally with a lip gripper and one hand supporting the midsection of the fish.  They found that all fish held vertically and 81% of fish held horizontally had holes in their lower jaws.  However, no fish had severe injuries as was seen with bonefish.  Furthermore, all fish resumed feeding within 3-5 days and all holes healed within three weeks.  The scientists also took x-rays of some of the barramundi to see if holding them with lip grippers had any effect on their vertebral alignment.  They found that holding barramundi vertically, and to a lesser extent holding them horizontally with the lip gripper causes vertebral separation.  None of the vertebrae separations recovered after three weeks. Being water dwellers where the water supports much of their body weight, holding fish in the air has the possibility of causing damage or separation to vertebrae.


Florida Largemouth Bass The most recent study on lip grippers was conducted on Florida largemouth bass and examined the differences between holding largemouth bass vertically with a lip gripper, by hand on the lower jaw using a tilted grip, and using a two-handed hold.  They found no difference in feeding behavior, survivorship, or rates of injury between any of the three methods of holding bass.  They did, however, find that largemouth bass that were held with the lip-gripping device took longer to recovery than other fish.


Why are these studies important to anglers?
    •    These three studies constitute a start to the much-needed research on lip-gripping devices, and given the diversity of these devises and the species they are used on, clearly there is more work to be done.
    •    What these studies do show is that there is a wide variation in how lip-gripping devices affect the incidence of injury on different fish species.
    •    What I could not find are any studies that examine repeated use of lip grippers, long-term affects on fish, or compare injuries from lip grippers to those caused by nets.  
    •    If tackle manufactures want to make claims that their lip grippers and other fish handling products do not harm fish, they should consider independent testing.

Happy Fishing!
Sascha Clark Danylchuk

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Involving recreational fisheries stakeholders in development ofresearch and conservation priorities for mahseer (Tor spp.) of Indiathrough collaborative workshops

The mahseer (Tor spp.) of India are a group of potamodromous cyprinids currently facing numerous challenges in their native ranges including overfishing, pollution, and hydropower development. As a result of such challenges, four of the seven Indian species of Tor have been listed as ‘Endangered’ on the IUCN Red List, including two of the most popular recreationally fished species, Tor khudree and Tor putitora.Stakeholders in the mahseer recreational fishery may serve as an ally for this group of iconic fishes, fostering aquatic stewardship and providing livelihood alternatives for poachers. Yet, information regardings pecies-specific responses to recreational fishing practices is lacking and a 2009 decree equating fishing with hunting in the Indian Wildlife Protection Act (1972) has since 2011 effectively banned angling within protected areas and rendered the future of mahseer recreational fisheries elsewhere uncertain. Read More.

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Evaluating the consequences of catch-and-release recreationalangling on golden dorado (Salminus brasiliensis) in Salta, Argentina

Golden dorado (Salminus brasiliensis) is increasing in popularity as a target of recreational anglers practicing catch-and-release (C&R) in northern Argentina and bordering countries, however science-based best practices have yet to be developed for this iconic freshwater game fish. We assessed the consequences of C&R on golden dorado captured by anglers on the Juramento River, in Salta, Argentina. Read More.

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Best practices for catch-and-release recreational fisheries – anglingtools and tactics

Catch-and-release angling is an increasingly popular conservation strategy employed by anglers voluntarily or to comply with management regulations, but associated injuries, stress and behavioural impairment can cause post-release mortality or fitness impairments. Because the fate of released fish is primarily determined by angler behaviour, employing ‘best angling practices’ is critical for sustain-able recreational fisheries. While basic tenants of best practices are well established, anglers employ adiversity of tactics for a range of fish species, thus it is important to balance science-based best practices with the realities of dynamic angler behaviour. Here we describe how certain tools and tactics can be integrated into recreational fishing practices to marry best angling practices with the realities of angling. While the effects of angling practices vary considerably across contexts and conditions, we also outline available methods for assessing fish condition by examining physical injuries and reflexes, which enable recreational anglers to make educated real-time decisions related to angling practices, as well as when, where, and whether to release captured fish based on their probability of survival. In cases where fish are in poor condition, there are recovery tactics available that can improve survival, although this is among the most understudied aspects of angling practices. Read More.

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Perceptions of recreational fisheries conservation within the fishingindustry: Knowledge gaps and learning opportunities identified ateast coast trade shows in the United States

"The recreational angling community is comprised of diverse stakeholders, including the trade sector responsible for the manufacturing, distribution, and sales of tackle, boats, and clothing, angler-based travel, revenue-generating popular media, and angling services. Through marketing and promotion, fishing companies compete for customers by convincing anglers as to what success means when they go fishing. If the angling trade can influence the social norms in the recreational angling community, then this could hold true for norms related to the conservation of recreationally targeted fishes and their habitats." Read More

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April Vokey's "ANCHORED" Podcast featuring Andy Danylchuk

Join well known angler, April Vokey, as she interviews some of the most influential people involved in the fishing world today. Learn more about their careers, opinions, history, relationships, and life both on and off the water. Click to play podcast.

Dr. Andy Danylchuk is a professor at the University of Massachusetts Amherst, a passionate angler, and a fellow fly fishing ambassador for Patagonia clothing.  His work covers both marine and freshwater systems, with a primary focus on stress physiology, behavioural ecology, spatial ecology, predator-prey interactions, and adaptations in life history as a response to disturbance.  Andy has been at the forefront of revolutionary science in the Bahamas, and is now currently spearheading a program taking place in Northern BC.  I met with Andy during his time up north to see if I could learn about the project that had so many people around me abuzz.

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Influence of hook type and live bait on the hooking performance of inline spinners in the context of catch-and-release brook trout Salvelinus fontinalis fishing in lakes

The objective of catch-and-release angling is for the fish to survive with minimal fitness consequences. However, fish survival can be compromised by a number of factors, especially anatomical hooking location. To evaluate whether hook type or bait influence hooking outcomes, we tested different combinations of hook (treble or single siwash hooks) and bait (hook tipped with worm or no worm) while angling for brook trout (Salvelinus fontinalis) with inline spinner-style fishing lures. Read More.

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Characterizing information on best practice guidelines for catch-and-release in websites of angling-based non-government organizations in the United States

Recreational catch-and-release angling is an important tool for managing fish stocks. As recreational fishing is often a culturally or community-based activity, many anglers look to local grassroots and other non-government organizations (NGOs) as a source of information regarding their angling practices. Read More.

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Best practices for catch-and-release recreational fisheries – angling tools and tactics

Just released study involving Keepemwet Fishing Science Advisor Dr. Andy Danylchuk.

"Catch-and-release angling is an increasingly popular conservation strategy employed by anglers vol-untarily or to comply with management regulations, but associated injuries, stress and behaviouralimpairment can cause post-release mortality or fitness impairments. Because the fate of released fishis primarily determined by angler behaviour, employing ‘best angling practices’ is critical for sustain-able recreational fisheries." Read more.

 

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