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Originally Posted by ROA
Slots won’t work on some (most) lakes in Alberta, to small of a lake, to eager of fish and too many anglers on the water. Every fish that grows into the slot gets caught and kept. Funny how right now today with minimum size limit lakes every dam pike and walleye is about 1 cm short. Take that same lake right now and then tell people that have to throw back if the fish is over xx size does nothing because there are no fish that big in the lake. Fact.
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That is not a fact... In fact if you provide us with a list of lakes you claim fall into this category I bet myself and others could prove your claims are false.
You are correct that a handful of our lakes have very few fish over the minimum size and of those fish very few are over what would be a logical upper slot size. The reason for this is not because there are no fish that grow big in these lakes. The reason is because these odd fish eventually get caught and then are taken home because there isn't an upper slot size in place to protect them...
For example lets use Buck Lake which is one of the closest lakes to this example that you can get.
http://aep.alberta.ca/fish-wildlife/...eport-2017.pdf
Very few numbers of walleye over 50 cm but as can be seen there are a few fish at 55 cm which would be a logical upper slot limit on lakes close to major cities. With that upper slot those fish now would be protected, would grow even larger and would go on to spawn for many more years.
Here are some excerpts from a couple interesting research papers on the subject.
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With combinations of low exploitation rates and minimal degrees of protection, minimum-size-limit strategies maximize postharvest abundance levels, but slot limits are most effective at inducing favorable shifts in population size structure. For combinations of high exploitation and protection, slot limits dominate minimum-size limits in terms of abundance, harvest, and population size structure. Although neither strategy can be considered universally superior, slot limits minimize the risks of a collapse in the fishery resulting from overharvest.
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https://www.tandfonline.com/doi/abs/...L%3E2.3.CO%3B2
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However, harvest slots consistently produced greater numbers of fish harvested and greater catches of trophy fish while conserving reproductive biomass and a more natural population age‐structure. Additionally, harvest slots resulted in less waste in the presence of hooking mortality. Our results held across a range of exploitation rates, life‐history strategies and fisheries objectives. Overall, we found harvest slots to represent a valuable option to meet both conservation and recreational fisheries objectives. Given the ubiquitous benefits of harvest slots across all life histories modelled, rethinking the widespread use of minimum‐length limits is warranted.
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https://onlinelibrary.wiley.com/doi/...1111/faf.12053