Write the report CER

Parallel case: A sudden fish die-off in a neighborhood pond. A student team investigated why hundreds of fish died overnight, pulling evidence from four independent streams.\n\nClaim: The most likely cause of the fish die-off is oxygen depletion triggered by an algae bloom, not direct chemical poisoning.\n\nEvidence by stream: Field, a dissolved-oxygen meter read far below the level fish need to survive at dawn. Lab, water samples showed nitrate and phosphate concentrations high enough to feed a large algae bloom. Biological, a thick mat of decaying algae covered the surface, and decay consumes oxygen. Records, the weather log showed several hot, still, cloudy days with no wind to mix the water.\n\nReasoning (convergence): These four independent streams point to the same explanation. Low oxygen, bloom-feeding nutrients, decaying algae, and calm warm weather each describe one part of the same chain, and when separate methods agree on one story the conclusion is strong.\n\nConflict resolution: One water test flagged a trace of a lawn chemical, which hinted at poisoning instead. I resolved this by trusting the repeated oxygen readings and the visible algae mat over a single trace measurement that was near the detection limit.\n\nLimitations: 1) I did not test the water on the days before the die-off, so I am inferring the bloom timeline rather than observing it directly. 2) Oxygen and nutrient data show a strong pattern but cannot by themselves rule out every other stressor, so the conclusion stays a reasonable-certainty finding, not a certainty.