What is a "summer squeeze" or summer kill for trout?
It is the vise that closes on trout in marginal lakes every July and August. From above, the warm surface layer pushes down — too hot to survive in; from below, the deoxygenated bottom layer pushes up — cold enough but unbreathable. The habitable slice between them can shrink to a band a couple of meters (a few feet) thick, and in bad years — hot summers, fertile water, heavy algae die-offs — the two fronts meet and the trout have nowhere left, producing a summer kill. This squeeze is also an angling map: in late summer, every trout in such a lake is stacked in that narrow band, typically where roughly 10–16 °C (50–61 °F) water still holds oxygen.
The full story
This answer is one piece of a longer lesson — setups, diagrams and the reasoning behind it.
More questions about Breathing & oxygen
Same topic, other species
- Where do crappie go in late winter under the ice? — Crappie
- How does the thermocline affect where largemouth hold in summer? — Largemouth Bass
- What is the late-summer oxygen squeeze? — Muskellunge (Muskie)
- What is winter-kill, and why does it shape so many perch lakes? — Yellow Perch
- What is winterkill, and why does it matter for pike lakes? — Northern Pike
- Does a summer smallmouth have to move deep? — Smallmouth Bass
- Why are walleye sometimes suspended out over the open basin? — Walleye