00:00

Question 57·Hard·Central Ideas and Details

Marine ecologist Marina Costa analyzed four decades of data from eight Mediterranean seaside towns that had banned bottom-trawling within two nautical miles of shore. The prohibition was enacted in the early 1980s to prevent the nets from stirring up sediment that accelerated beach erosion, a threat to the region’s tourism economy. Costa’s new survey shows that, compared with similar towns without the ban, the protected waters now host 40 percent more adult fish and nearly double the coverage of seagrass meadows, a critical nursery habitat. Costa notes that no complementary fisheries regulations—such as catch limits—were introduced during the period. She argues that the findings illustrate how “policies aimed at solving one problem can, decades later, solve another we never anticipated.”

Which choice is most strongly supported by the information in the passage?