The Nuances of Best Practices in Recreational Fishing

The Nuances of Best Practices in Recreational Fishing

by Dr. Shannon Bower

Lately, I’ve been thinking about a conversation I had a while ago. Partly out of guilt, because I have been a Science Ambassador for Keepemwet for quite some time and have been a fairly silent contributor of late, and partly because the issue of responsible fishing is always on my mind.

When you work in this field for a while, you learn that you can’t be militant about responsible fishing practices. There is simply too much variation in recreational fisheries to know what genuinely good practice is in every single situation. We have some great guidance papers, like Elmer et al. 2017, Brownscombe et al. 2017, and Sims and Danylchuk 2017 (2017 was a good year for best practices research, apparently!) and each of these offers a different take as well as some similar advice. This is a good sign that denotes a lot of agreement among researchers on this issue.

An image from the Brownscombe et al. 2017 paper that shows the different choices that anglers can make and the items they can have handy throughout the process of catching and releasing (or deciding to keep) a fish.

One place where we have some challenges in the field is in the arena associated with individual species. There was a paper by Cooke and Suski in 2005 that asked the question of whether we needed species-specific research to better understand fishes’ responses to catch-and-release. The answer was an emphatic yes, and the authors explored a range of reasons why, including arguing that we see so much variation that it’s difficult to accurately predict how each species will respond in a particular set of circumstances. In terms of variation though, Cooke and Suski pointed out that individual fish respond differently to the same catch-and-release practices, in much the same way that you or I would perform differently if asked to blow bubbles in the water for a full minute, i.e., I would fail miserably and you would probably do fine. As scientists, we’re interested in how the average fish responds to catch-and-release practices like air exposure, but we’re also interested in the range of responses for the whole population that we sample. There are as many potential sources of variation as there are types of responses to catch-and-release, and because of this, Cooke and Suski recommended that we get to work at understanding this variety of responses at the species level.

I think the same can be said for understanding best practices at the scale of individual fisheries, which is where this conversation that I had a few years ago keeps popping into my head. I’d made a post on my Facebook page about using nets when fishing. I had noticed a lot of people using cheap lip gripping devices on fish species with soft mouths that had no teeth. I was seeing photos of anglers in my study area using these devices to hoist the fish vertically out of water, and I wondered just how much pressure these cheaply made devices were putting on the fish’s jaws. I’d turned to the research to see if anyone had asked the question about the effects of lip gripping devices on fish and found a few articles that did nothing to alleviate my concerns (for example, Danylchuk et al. 2008, which was discussed here in an earlier blog. I had suggested that these anglers use nets instead, and to keep those nets in the water while removing hooks and preparing to release the fish. My logic was that the fish would be spared potential damage to the jaw and the air exposure being evidenced by the use of lip grippers. The risk was big though: if you’re using nets, you need to use rubberized nets to avoid damage to the fish’s body. Thrashing in a net that is not rubberized can lead to all kind of badness: major loss of slime that protects fish from infection, and physical damage such as slices and bruising being the two most major that come to mind. So, while I was clear to suggest using rubberized nets, I was also aware that these were not common in the area where I work and that I could be suggesting anglers simply trade one form of potential damage for a form of known damage to fish.

Raja PK photo.

Shannon Bower photo.

This advice didn’t sit particularly well with me, despite being the one who’d given it. I sat staring at the screen, thinking about phrasing, and wondering if there was a better avenue of action to suggest, when the telltale ping came through on my phone. It was a friend from Australia, also a recreational fisheries scientist, who disagreed entirely with what I’d written. What was of interest to me though wasn’t the disagreement, it was the reasoning behind it. You see, in his area of Australia, fishing mainly in marine waters, many anglers have learned that using lip grippers can be a very good way of avoiding the use of damaging nets, provided the lip grippers are suitable for the species and used properly. Those two provisos are a big deal: these anglers were using good quality devices that were appropriate for local toothy species and they were trained in how to use them properly. By doing so, the use of lip grippers was actually a best practice in the area. Yet in the area where I worked, using lip grippers was decidedly NOT representing a best practice. Best practices are not always universal. Like the Cooke and Suski paper arguing for species-specific research, I spend a fair amount of time arguing for fishery-specific research. We have a good sense of what many best practices are, but we don’t know how these best practices play out in different fisheries, in different communities, in different cultures and countries around the world.

Dave McCoy photo

All of this means that we have our work cut out for us as scientists. Incidentally, this is also the reason I am such a big fan of Keepemwet and their work. Of all the best practices, arguably the only one that is one hundred percent universal is: keep the fish in the water. When it comes to building local and fishery-specific understanding of responsible fishing practices, that is a great place to start.

THE POINT OF HOOKS

The point of hooks

By Sascha Clark Danylchuk

Hooking damage is the the number one cause of mortality for fish that are caught-and-released. That’s not a surprising statement since hooks are the only commonality for all fish caught by recreational anglers. But what that statement doesn’t address is how and why fish die from hooking damage. If every fish that is landed has a hook wound, what is it that makes some fish die and others live? How much damage do hooks actually cause? Does it matter what type of hook you use? What other factors come in the play to determine if a fish lives or dies after being hooked?

This paper looks at hooks and specifically hooking mortality in many different studies. It’s called a meta-analysis, which is a statistical analysis that combines the results of multiple scientific studies. It’s also a great introduction to Dr. Robert Arlinghaus, our newest science ambassador. Robert’s work is often based a social-ecological systems approach, which means that he looks at fisheries issues through the lens of both fish ecology and social science. You can learn more about Robert here.

What did they do?

Looked at hooking mortality studies for fishes that are important in European freshwater recreational fisheries. All species in a genus were included, even if the species were not found in Europe. Studies conducted anywhere in the world were included in the study.

• 107 studies on 8 European species and an additional 10 species from the same genus.

• Extracted what caused mortality from each study:

Water temperature

Fish length

Hook type (singe vs. treble)

Existence of a barb (barbed vs. barbless)

Type of bait (natural vs. artificial)

What did they find?

Across all studies and species:

• Mean hooking mortality was 15.9%, with a range of 0 to 88.5%.

• Half of the studies reported hooking mortality of less than 10%. Only a few studies reported mortality levels over 50%.

• Factors that are important for hooking mortality:

1. Water temperature (higher water temperatures lead to higher mortality rates).

2. Bait type (average mortality for artificial baits was 11.4%, average mortality for natural bait was 25%)

3. Existence of a barb (average mortality for barbless hook was 8.2%, average mortality for barbed hooks was 14.6%).

For Salmonids:

• Results for trout and salmon species was similar to the overall results.

• Factors that were important for hooking mortality:

1. Water temperature (higher water temperatures lead to higher mortality rates).

2. Bait type (average mortality for artificial baits was 11.6%, average mortality for natural bait was 27%)

3. Existence of a barb (average mortality for barbless hook was 8.6%, average mortality for barbed hooks was 15.1%).

Takeaways:

• The good news is that most of the reported hooking mortality rates were very low (less than 10%).

• High mortality was most often due to deep hooking or when fish were caught at high water temps.

• There are several reasons why barbed hooks could lead to higher mortality rates than barbless hooks: barbed hooks have been known to cause more injury and bleeding, they also take longer to remove which often increases handling time and air exposure (both things known to lead to worse outcomes for fish), and either or both of these could increase stress levels in fish which also leads to poorer outcomes for fish after release.

• Despite the fact that in this study hook type (single vs. treble hooks) did not turn out to be significant, the authors think that hook type is a species specific issue and likely dependent on hook size as well as the mouth morphology of the fish, and the type of fishing. All these factors could not be teased out in the present study, but are likely important on a species by species basis.

Keepemwet Fishing, Fisheries Research

At Keepemwet Fishing we believe that communication and knowledge sharing between the fisheries science and recreational angling communities is a two way street.   For example, anglers can learn more about fisheries science, and scientist can learn about the issues that are important to anglers and this can help inform their research.  We need this type of dialogue and interaction to make sure that catch-and-release is effective.   Scientists communicate and share their work and ideas through the publication of peer-reviewed articles in scientific journals, and so, here is our first contribution on Keepemwet Fishing to science literature.

"There is a growing body of catch-and-release (C&R) science showing that adjusting the way fish are caught, handled, and released can reduce impacts on individuals and populations. However, a major caveat is that C&R will be a more effective conservation tool if best practice guidelines stemming from the science are understood, embraced, and adopted by recreational anglers. In recognition of this, Keepemwet Fishing (KWF) has emerged as a nonpartisan movement to provide simple, clear, and accurate C&R guidelines that transcend species and subcultures within the recreational angling community". Full report here.

Bulkley Steelhead Catch-and-Release Project

Will Twardek photo

Recreational fisheries for steelhead are primarily catch-and-release, including the famed run of the Bulkley River, BC. The success of catch-and-release as a conservation tool is based on the premise that released fish survive and do not suffer any negative consequences. Science has shown, however, that angler behaviour can have dramatic influences on the outcome of catch-and-release angling, and that research is needed that specifically focuses on wild steelhead to identify opportunities for refining handling practices to ensure the best outcome for fish.

Scientists on this project worked alongside volunteer anglers on the Bulkley River to study wild steelhead from Sept 2016 to April 2018.  During this time, 126 wild steelhead were caught and used in one of two studies on the impacts of catch-and-release.  Click here for a full summary of the project.  

Read the published studies here, here, here, and here

What Did They Say? Translating Presentations From the BTT Symposium Part 3

What happens to bonefish when there are sharks around?

Presentation by Robert J. Lennox
Carleton University

My happy place is wading a tropical flat for bonefish.  The subtle complexity of flats ecosystems fascinates me and the diversity of catchable species means that there could be another fish just beyond my sight line.  The predators that are often found on flats also keep things lively, but makes fishing and practicing catch-and-release a much more dangerous game for the fish.  

While there have been several studies examining the rate of mortality/predation of bonefish in the Atlantic, this is the first study to look at post-release predation in the Pacific on Albula glassodonta.  It’s also the first study to look at post-release predation in an area that is very sharky (why yes, that’s a technical term).  The small atoll in French Polynesia where this study was conducted has a huge abundance of blacktip reef sharks.  They follow anglers on the flats like puppies and it’s not uncommon to see over a dozen sharks on a single flat.  Understanding how bonefish fare in this type of situation is essential for our understanding of the impacts of catch-and-release.  

What did they do?

• Study 1: caught bonefish and air exposed them for either 0, 10, or 30 seconds. Released the fish with a small visual tracking bobber similar to those used in FINSIGHTS 5.

• Study 2: caught bonefish and either released them right away or placed them a recovery bag (originally developed for Atlantic salmon, and tested on bonefish in the Atlantic) for 30 minutes to let them rest after angling and see if they could reduce post-release predation rates.

What did they find?

• Study 1: bonefish with no (0 seconds) of air exposure were much less likely to be attacked by sharks than those with 10 or 30 seconds of air exposure. Bonefish (regardless of air exposure duration) were vulnerable to sharks for at least 20 minutes after release.

• Study 2: Recovery bags did not help reduce the chance of post-release predation for bonefish.

• The authors hypothesize that the recovery bags were not effective because, despite the fact that the bonefish inside them were able to rest and be protected after angling, the sharks were still able to “smell” the bonefish and were attracted to the area. Previous studies have shown that angled bonefish excrete stress hormones and that sharks are attracted these hormones.

Why is this study important?

• This is the first study to show that even 10 seconds of air exposure can significantly impact the post-release predation rates of bonefish.

• Despite the lack of effectiveness of the recovery bags used in this study, the idea of finding a way to help fish recover from angling, especially in areas with a lot of predators is definitely worth pursuing and could lead to the development of new techniques for the best practices for catch-and-release.

Acknowledgements

A special thanks to Ed Anderson who donated the artwork accompanying these summaries. Thank you to the presenters and their collaborators for the work that contributed to these presentations, and for allowing us to represent them in these summaries.  Thank you as well to Natasha Viadero, Alora Myers, and Jordan Massie who provided assistance during the symposium.

Fish reflex tests - a valuable tool for anglers

by Dr. Jake Brownscombe, PhD
Research Associate, Carleton University
Keepemwet Science Ambassador

“Have a seat, Jake” the doctor said as she pulled out a small rubber mallet and proceeded to thump me on the knee with it. My leg kicked outward involuntarily. “Your nervous system is in good condition” she assured me.

If you grew up on this planet, you know the doctor was checking my knee-jerk reflex. Perhaps lesser known, the speed and intensity of this reaction can indicate internal nerve damage or the presence of disease. It’s a simple external test that indicates what is going on inside of the human body.

Fish have reflexes too. And they can tell us a lot about their internal condition, such as their level of stress, ability swim or to perceive predators. This is particularly useful for anglers because fish cannot tell us how they are feeling. If you ask a fish “If I let you go, can you swim well enough to survive?” its response will be inconclusive. Trust me, I’ve tried… more times than I’d care to admit.

The idea behind catch-and-release fishing is that the fish will survive, grow bigger to be caught again, and continue to contribute to the population. Yet, we know this isn’t always the case. Fish sometimes suffer mortality after release due to stress or injuries associated with angling (but the odds of this can be minimized substantially by using best practices - see this paper for an overview). Whether or not a fish survives depends on its condition, which can be hard to assess as an angler without any fancy medical or veterinary tools.

That is, until recent research developed a set of reflex tests that can be applied to fish, by anglers, to assess their condition. These are the four most effective reflex tests, how to do them, and what they tell you:

1. Escape response

How to do it:  With the fish in the water in a net or livewell (scientific holding pen shown here), approach the fish from behind and grab at its tail. Observe if the fish attempts to escape.

What it means: If a fish doesn’t try to swim away it fails this test, has at least some level of impairment and could be at risk of mortality - other tests will provide further insights.

2. Righting response

How to do it: Flip the fish upside down (belly up) in the water and let go. Observe if the fish rights itself within 5 seconds.

What it means:  If a fish cannot right itself within five seconds it fails this test, and is in poor condition and at risk for mortality.

Pro tip: Count the amount of time until the fish rights itself and note whether it struggled to do so. If a fish rights itself quickly and with ease, it is in good condition to swim away immediately.

3. Regular ventilation

How to do it: Holding the fish in the water, observe for regular, consistent ventilation (opening and closing) of the operculum (gill plates).

What it means: If a fish isn’t ventilating at regular intervals, it fails this test, and is highly impaired and at high risk for mortality.

4. Eye tracking

How to do it: Holding the fish in water, roll the fish side-to-side, observing whether its eye(s) remain level (passes test), or roll with the body (fails test).

What it means: If a fish fails this test, it is highly impaired and at very high risk of mortality

While these aren’t true reflexes by strict definition, they are responses that are always present in fish unless impaired due to stress. The above tests are presented in order of operation, starting with escape response. If a fish fails this test, proceed with the righting response test, and so on. If a fish has no reflex impairment, the best course of action is to release the fish immediately to reduce handling time. However, if there is reflex impairment, particularly loss of righting response, anglers can hold fish in a net or livewell until its condition improves. Further, on any given fishing day, if captured fish are repeatedly in poor condition, anglers can consider altering their fishing practices (e.g., use different lures or fish in different locations) to minimize their impact on fish.

The Science:

The concept of using reflex tests as an indicator of fish condition was first developed and applied in the context of commercial and aboriginal seine net fisheries for Pacific salmon (see these two articles for reference) 1, 2. Based on the success of multiple studies in predicting salmon survival using reflex tests, scientists began apply these tests to recreational fisheries. This study found bonefish with impaired righting response are six times more likely to suffer predation post release (see Finsights #5). Another study later showed that reflex impairment indicates that bonefish have reduced swimming and decision-making capabilities post release, which is why they are more vulnerable to predators. Reflex tests are now used widely as measures of fish condition for diverse species such as sharks, great barracuda, largemouth bass, and fat snook. As science continues to develop the relationship between reflex tests, fish condition, and survival, these tools will become increasingly useful for anglers to assess the condition of their fish and make informed decisions about how to treat the fish prior to release.