Sacramento Perch vs. Bluegill

Water Chemistry & Competitive Displacement in California Waterways

Agricultural runoff is slowly acidifying the waterway — shifting pH from alkaline toward neutral. Sacramento Perch thrive in high pH; Bluegill dominate as conditions shift.

Your job: use research credits to intervene and keep the native perch colony alive as long as possible. Defend nests, manage the population, and fight the chemistry clock.

Choose Your Interventions

Select exactly 3 tools you'll have available this session. Hover each card to read what it does.

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Sacramento Perch vs. Bluegill

Water Chemistry & Competitive Displacement in California Waterways

Survival time 0:00 colony alive

Agricultural runoff is slowly acidifying the waterway. Use research credits to intervene — but the pressure never stops.

Current Conditions

9.50

Water pH

6.57.58.59.510

↓ Drifting toward neutral

Strongly alkaline. Perch breeding undisturbed.

Live Population

Sac. Perch

Bluegill

Nests

Research Credits

500

+5 credits / sec

Spent: 0 ¢

Birth / Death Ratio

Perch — —

Bluegill — —

Bluegill Aggression

PassiveExtreme

Sacramento Perch (native)

Bluegill (introduced)

Nest · green glow = defended

🔬 Human Intervention

Stock Fish

150 ¢

Electrofishing

350 ¢

Vegetation

450 ¢

Add Substrate

350 ¢

Iso. Barrier

500 ¢

Buffer Strip

750 ¢

¢ = research credits · Stock Fish: 150 · Add Substrate: 350 · Iso. Barrier: 500

Population & pH Over Time

Sac. Perch

Bluegill

Nests

pH (right)

Stocked

Substrate

Barrier placed

Vegetation

Electrofishing

Sacramento Perch — Colony Lost

pH reached — · Colony survived —

Colony survived

—

Peak perch pop.

—

Final pH

—

Fish stocked

—

Nests placed

—

Barriers placed

—

Total spent

—

Credits earned

—

Full Run History — scroll to explore

Perch Bluegill Nests pH ▼ Stocking ▲ Substrate ◆ Barrier placed ▲ Vegetation ◆ Electrofishing