What climatic changes threaten wild rice in the Great Lakes region?

• A. Lakes becoming deeper
• B. Lakes drying up
• C. Warmer summers improve growth
• D. Stronger currents

Answer: (A)

Wild rice grows best in shallow, sunlit, calm water where it can root in soft sediments and receive enough light. If climate changes cause lakes to become deeper, the shallow fringe where wild rice thrives shrinks and the plants can be submerged beyond their optimal depth. Reduced light reaching the bottom and less suitable habitat make it harder for wild rice to germinate and grow, so deeper lakes threaten these populations.

Other options miss the main mechanism. Warmer summers aren’t as directly harmful as the loss of shallow habitat, since wild rice relies on depth and light more than temperature alone in this context. Stronger currents disrupt beds, and lakes drying up remove habitat altogether, but deeper water specifically reduces the available suitable habitat for wild rice, making it the best fit for the threat described.