Question: A marine biologist samples 5 coral colonies from a reef where 30% are bleached. What is the probability that exactly 2 colonies show bleaching?

Mon, 04 May 2026 18:00:52 +0000

**A Marine Biologist Samples 5 Coral Colonies—What Is the Probability Exactly 2 Show Bleaching?**
When a marine biologist collects samples from a reef where 30% of coral colonies exhibit bleaching, a compelling question arises: *What is the likelihood that exactly 2 out of 5 sampled colonies show bleaching?* This probabilistic inquiry reflects growing public interest in coral reef health amid concerning global bleaching trends. With climate stressors intensifying and reef ecosystems under pressure, understanding statistical patterns behind bleaching events helps inform conservation efforts and scientific assessment. The question taps into both public curiosity and urgent environmental reporting, making it highly relevant for informed, mobile-first audiences navigating climate-related news. Why this question is gaining traction in the U.S.
Coral bleaching—when warm or stressed conditions cause corals to expel symbiotic algae—has emerged as a visible indicator of reef vulnerability. Recent reports highlight alarming bleaching percentages across major U.S.-affiliated reef systems, including the Caribbean and Hawaii, with subsets of reefs showing 30% bleaching rates. As audiences seek data-driven context for these events, simple probability questions like this help translate complex ecological dynamics into accessible, actionable knowledge. Moreover, growing awareness around marine conservation and climate adaptation fuels demand for factual insights, positioning this inquiry at the intersection of science, environmental news, and public education—ideal content for Discover algorithms focused on trust and relevance. How coral bleaching probability works: A step-by-step explanation
Probability models like this one rely on the binomial distribution, which calculates the chance of observing a specific number of “successes” in a fixed number of independent trials—here, coral colonies sampled. Each reef colony has a 30% probability (or 0.3 chance) of being bleached, independent of others. Sampling 5 colonies means considering all combinations where exactly 2 meet that bleached threshold. This approach provides a scientific method to estimate risk levels in ongoing reef monitoring, helping researchers assess variability and inform restoration strategies with measured precision. Common questions people ask
H3: What does the binomial model tell us here?
It confirms the likelihood of exactly 2 bleached out of 5, given a 30% baseline bleaching rate. The model assumes independence, constant probability, and repeated trials—