Sea otters are part of a giant kelp ecosystem. they feed on sea urchins that feed on kelp. how does hunting sea otters affect the population of sea urchins and kelp in the ecosystem? a. the sea urchin population decreases, and the kelp population increases b. the sea urchin population decreases, and the kelp population decreases c. the sea urchin population increases, and the kelp population decreases d. the sea urchin population increases, and the kelp population increases