Practice Test 4

Researchers studying microplastics report that particles can be transported long distances by ocean currents and wind, reaching remote ecosystems far from major cities. _______ even isolated mountain lakes have been found to contain plastic fibers, indicating that pollution sources and impacts are not confined to densely populated areas.

Researchers observed that when a coral reef experiences repeated bleaching events, its fish community often shifts toward species that tolerate warmer, less complex habitats. _______ this shift can reduce grazing pressure on algae, allowing seaweeds to overgrow corals and making reef recovery even harder after the heat stress ends.