Woodland Woman

Those of you who follow me on Instagram know that my fiancé and I have been learning to fish this year. Its been a lot of fun. Most of the fishing we do is catch and release. I was curious about how catch and release affected fish so I did the research. In this post, I discuss how to minimize mortality and sub-lethal stress in bass.

Do Fish Survive Catch and Release? 

Many anglers assume that the fish they catch and release survive. But, catch and release does lead to death in fish. The survival rate of released fish depends on the species and how you handle the fish. A survey of over 100 catch and release studies estimates that 16.2 percent of fish die from catch and release. The good news is that bass are a resilient fish and there are things that you can do to help reduce mortality.

The Effects of Sub-Lethal Stress on Caught Fish

Besides death, you also want to avoid causing a fish too much physiological stress. This sub-lethal stress can reduce growth, impair sexual reproduction, and increase susceptibility to disease.

Studies have shown that the growth of smallmouth bass is related to the amount of hookings. Angled fish were smaller than those that had never been hooked or were hooked less. 

Being hooked also affects how largemouth bass care for their eggs: “fish that were angled incurred increased brood predation and increased likelihood of brood abandonment. Similarly, smallmouth bass have been found to have reduced ability to defend their broods after being angled from their nest” (Ontario Ministry of Natural Resources).

Best Practices:

1. Know Federal and Provincial Regulations

First and foremost, it’s important to know and follow provincial and federal regulations and Acts relevant to the use of fishes and their habitats. These regulations are in place to ensure the survival and health of fish colonies. Regulations differ from province to province and even region to region.

2. Use the Right Equipment

Fishing Line: Using the right equipment for the fish you are trying to catch will enhance the rate of survival. Choose a rod and line that is adequate for bass fishing. Fishing lines are rated for their strength in pounds. An 8 – 12 pound fishing line should be good for bass fishing. Check out these posts from Bassmaster and Karl’s Bait and Tackle for more information.

Hooks: Barbless and circular hooks reduce the harm done to fish. Circle hooks can decrease mortality rates by 50 percent! They also make it easier to release fish. Some provinces, like Manitoba and Alberta, have mandated barbless hooks to minimize the damage of catch and release. If you don’t have barbless hooks, you can pinch or file the barbs down.

It’s important that you know how to properly tie a hook to a line. We use a uni knot. You can learn how to tie that knot here and here. 

Baits: Fish ingest natural and scented baits more deeply than artificial baits. This can increase the rate of death. Smallmouth bass caught with minnows had a 10 percent increase in mortality compared with those caught on spinner lures. 

Nets: If you are going to use a landing net, use a knotless rubber net. Landing nets can cause damage to fins and wipe away the protective mucus that fish have on their bodies. Knotless rubber nets will help reduce this damage.

3. Handling a Fish

A common catch and release injury that leads to death is a broken jaw. A fish with a broken jaw will die of starvation. This injury happens when people hold a heavy fish at an angle from its mouth. You often see this when people take pictures with the fish they caught. If you want to hold a fish this way, support its body weight with the other hand – like this.

Handle a caught fish as little as possible. This reduces the stress the fish experiences and doesn’t wipe off the protective coating on its skin. If you are going to handle a fish, do it with bare wet hands and never touch their gills and eyes. Avoid squeezing the fish because this can rupture their internal organs and damage gills and scales. 

Don’t carelessly throw a fish in the water. Release it gently. If the fish is weak, hold it lightly by the belly and the tail under the water. If the water is moving, face the fish into the current. When the fish gains strength, it will swim away. 

4. Minimize the Time Out of Water

It’s important to minimize the time a fish is out of water. When fish gills are exposed to air they collapse increasing the amount of carbon dioxide in the blood and decreasing the amount of oxygen. If possible, try to remove a hook while the fish is still in the water. A single hook can be easier to remove than a treble hook.

5. Reeling in a Fish

While its best to reel in a fish slowly, extending “play time” can exhaust a fish making it less likely to survive once released.

6. Gut Hooks

A gut hook is a hook that has been deeply swallowed. 56 percent of largemouth bass that were gut hooked died. You can avoid gut hooking a fish by never leaving your fishing rod unattended and avoiding live and artificially scented baits.

There’s a lot of debate whether you should remove a gut hook or cut the line to increase the rate of survival. A study of seabass showed a 24 percent increased rate of survival if the line was cut and the hook was left in place. Of the fish that survived, 39 percent of hooks became dislodged.

7. Bleeding Fish

A bleeding fish is not likely to survive catch and release. Instead of releasing the fish to further suffer, if you are allowed, kill it swiftly and consider it part of your daily quota. You might consider doing the same for gut hooked fish and fish caught by the gills.

Happy Fishing!

While catch and release does have an impact on fish, these tips can help you minimize mortality and sub-lethal stress. This is not only good for fish, but it helps ensure good fishing for years to come.

Resources

Here are the resources that I drew on to write this article. You can check out these pages and studies for more information:

Recommendations from the Ontario Ministry of Natural Resources, Nova Scotia Government, Parks Canada, and BC Ministry of Forestry, Lands, and Natural Resource Operations.