Complex sentence: Opala was one of the first scholars to recognize the significant historical ties between Sierra Leoneans and Gullahs, and the first to recognize that Bunce Island has greater importance for African Americans than any other West African slave castle.
Split into simpler sentences: Opala was one of the first scholars to point to the significant connection between Sierra Leoneans and Gullahs. And he was the first to recognize that Bunce Island has greater importance for the Gullah people--and for African Americans in general--than any other West African slave castle.