Why do walleye have boom and bust year-classes?
Because with no parental care, an entire lake's reproduction rides on two or three weeks of spring weather. Eggs incubate in the rubble for roughly two to three weeks, and everything must cooperate: a cold snap can stall hatching or kill embryos, a drop in river flow can dewater eggs, storms can smother them in silt, and the fry that do hatch must meet the zooplankton bloom on time or starve. When it all lines up, a "boom" year-class results that dominates the fishery for a decade; when it fails, that cohort is simply missing. Anglers feel this as multi-year waves — the flood of 35 cm (14 in) fish today is one good spring from years ago, and the gap behind it is a bad one. It is also why biologists index spring hatches the way farmers watch harvests.
The full story
This answer is one piece of a longer lesson — setups, diagrams and the reasoning behind it.
More questions about Spawning
Same topic, other species
- How deep do crappie spawn? — Crappie
- How do I find largemouth beds? — Largemouth Bass
- Why are pike fry so dangerous to muskie fry? — Muskellunge (Muskie)
- Do perch guard their eggs like crappie or bass do? — Yellow Perch
- What do spring water levels have to do with pike conservation? — Northern Pike
- Where do smallmouth build their nests? — Smallmouth Bass
- Do trout guard their eggs or young like bass do? — Trout (Rainbow · Brook · Lake)