"Dead zones" in US coastal waters have grown 30-fold since 1960, according to a recent government report. This report refers to which of the following environmental pollution issues?

Dead zones form when excess nutrients enter coastal waters, often through fertilizer and detergent runoff. The nutrients trigger algal blooms; when the algae die and decompose, oxygen in the water is depleted, making it difficult for aquatic life to survive. This process is called eutrophication, so the best answer is eutrophication caused by fertilizer and detergent runoff.

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