Overgrazing by purple sea urchins has what effect on their predators' interest?

• A. Increases their interest
• B. Reduces their interest
• C. Has no effect on predator interest
• D. Attracts more predators to the area

Answer: (B)

When habitat structure and prey availability are disrupted by herbivore overgrazing, predators lose hunting grounds. Purple sea urchins grazing heavily on kelp remove the kelp canopy that provides shelter and a diverse prey base. With less kelp and fewer prey in the area, predators are less attracted to or able to hunt effectively there, so their interest in that spot decreases. The other options don’t fit because the degraded habitat and reduced food resources make the area less appealing to predators, not more.