The Cottager's Guide to Conservation: Sustainable Fishing

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Since small fish make up the main part of the Great Blue Heron’s diet, this bird is strongly connected to the food web of the lakes and streams it inhabits. It can be considered one of the top predators in freshwater ecosystems, and any change in the abundance of fish in these ecosystems will ultimately have an effect on the herons¹³. Great Blue Herons aren’t always the only anglers however, and sometimes they must share the lake’s fish population with human anglers and recreational fishermen. For example, although herons mainly eat small fish they also sometimes eat fish that are attractive to anglers, such as trout¹⁴. A survey conducted in 2005 revealed that 31% of all resident anglers in Canada fish in Ontario, and that 26% of all fish caught and kept in Canada came from Ontario lakes and streams¹⁵. This is an underestimate of the total amount of angling in Ontario, as it does not take into account tourist fishermen or the effect of tournaments on local fish populations. Therefore these are not small numbers when you consider how little habitat is available to herons and how heavily they depend on its fish to survive and breed.

The amount of fish being caught and removed from lakes in Ontario has been documented, but it is hard to determine the size of fish populations in every lake and whether or not these populations are of a healthy size. It would take extensive monitoring programs to track the effect of angling on local food webs across Ontario, which are not entirely feasible or fundable. Many times declining populations are not detected until their collapse results in large-scale, wide-spread effects in the ecosystem. It is a great tragedy when these declines and collapses are caused by human activities, oftentimes unknowingly. Therefore it is important to be aware of the fact that activities such as angling do have a direct impact on lake ecosystems, and to fish sustainably in order to keep the balance in check. If this balance is conserved, we can continue fishing alongside the herons in peace, knowing that our impact is minimal and that both fish and herons will still be there next year.

Source: http://www.dpi.nsw.gov.au/__data/assets/image/0008/308159/coffs-and-urunga.jpg

How you can help

There are many small things that can be done to ensure that fishing is sustainable and does little harm to the local fish populations. The Canadian federal and provincial governments already have many measures in place to ensure that local populations are not over-fished, such as mandatory release of fish under a certain size. This allows younger fish to survive in the lake long enough to reach sexual maturity and breed. Without this regulation anglers could figuratively kick the legs out from under fish populations and they could collapse with even moderate fishing pressure. This catch-and-release method is one of the best ways to conserve fish populations and ensure a continued balance between population growth and removal of fish through angling. However, it is important to minimize stress on the fish if it is to be released again, as too much stress or injury could lead to death or decreased performance later on. Below is a list of guidelines that when followed, even if only in part, increase chances of angled fish surviving to live and breed.

Guidelines for Catch-and-Release Fishing¹⁶

Angling techniques

Circle hooks should be used as they minimize the chance of deep hooking.
Barbless hooks are recommended as they are easier to remove and reduce handling time.
Live/organic bait should not be used as it increases the chance of deep hooking.
The use of artificial lures is encouraged as they have the least impact on fish health.
Fishing lines must not be left unattended as they have a greater chance of deeply hooking a fish.
The type of line used should be appropriate to the target fish species. This will prevent line breakage and reduce playing time.
Angling should be avoided during extreme water temperatures if release is planned.

Landing a fish

Fish should be retrieved as quickly as possible to prevent fish exhaustion.
Fish should be landed by hand whenever possible.
When a landing net is required it should be knotless and preferably made of soft rubber.
When landing extremely large fish (ex: muskellunge) a landing cradle should be considered.

Rubber landing net

(source: http://media.basspro.com/images/articles/Nets_rubber_200.jpg)

Knotless mesh landing net

(source: https://www.flyfishingpoint.net/data/web/eshop/Tvrdek/Tvrdek%20386-29.jpg)

Landing Cradle 16

Handling and Photographing a Fish

Keep fish in the water as much as possible to minimize air exposure.
Never place your fingers through gills or in the eyes.
Don’t hold heavy fish by the jaw as this may damage the jaw and vertebrae.
Hold large fish horizontally and support its body to avoid damaging the internal organs.
Use wet hands or wet cloth gloves to handle the fish.
Have camera ready prior to landing the fish to minimize air exposure.

Unhooking a Fish

Have long-nose pliers available to back the hook out.
Remove the hook quickly, keeping the fish underwater if possible.
If the fish is deeply hooked it is best to cut the line and quickly release the fish.
Avoid using stainless steel hooks as they take longer to corrode if left in the fish.

Depressurization

Avoid fishing in deeper waters (5-6m) if you intend to release your catch.
If fishing in deeper waters is unavoidable it is best to release the fish quickly after it is landing.
Avoid artificial swim bladder deflation (“fizzing”). This technique actually does more harm than good.

Revival

If there is a current, hold the fish upright and facing into the current.
If there isn’t a current, gently move the fish back and forth in the water until gill movements return to normal and it is able to maintain its balance.
When the fish begins to struggle, let it swim away.

Following even a few of these guidelines is healthier for the fish, for all the organisms affected by the fish, and for future anglers looking to fish the same lake!

To find out more about sustainable fishing check out these websites: