Can I catch perch during the spawn itself?
Yes, and often very well — because perch guard nothing. Spawning is a night-and-dawn affair at roughly 7–12 °C (45–54 °F): egg ribbons go over weeds and wood in 0.5–3 m (2–10 ft), and by day the same fish are loose in and around the bays, still eating. There is no bed-guarding pause like bass have, so the "spawn bite" is really just shallow, concentrated fish. Most jurisdictions keep perch open year-round for exactly this reason, but seasons and limits vary — check your local regulations before fishing a spring run.
The full story
This answer is one piece of a longer lesson — setups, diagrams and the reasoning behind it.
Same topic, other species
- Why do muskie spawn after pike, and what does it cost them? — Muskellunge (Muskie)
- What does pike spawning actually look like? — Northern Pike
- Can I fish for smallmouth in early spring anywhere I want? — Smallmouth Bass
- What does the spring rainbow trout run look like? — Trout (Rainbow · Brook · Lake)
- What does the walleye spawn itself look like — and can I fish it? — Walleye