Final answer:
Floodwater runoff can harm the Great Barrier Reef by increasing nutrient concentrations in the water, leading to algal overgrowth and reduced oxygen levels, endangering marine life.
Explanation:
Floodwater runoff from the land can negatively impact the biodiversity of the Great Barrier Reef in several ways. One significant impact is increasing nutrient concentration in the water. Excessive nutrients lead to algal overgrowth, blocking light from coral polyps and causing death of fish and other species due to decreased oxygen levels. This process, known as eutrophication, threatens coral reefs and biodiversity.
Learn more about impact of floodwater runoff on biodiversity in the Great Barrier Reef here:
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