In many developing regions of Melanesia, fishers' traditional ecological knowledge (TEK) has been integrated with western science and management knowledge (SMK) to generate innovative and effective fisheries management. Previous research suggests that three factors initiate this process: depleted fishery stocks, limited SMK, and ownership of resources by local communities. In other contexts the extent of power-sharing through comanagement, and the cultural significance of species may also be important determinants of knowledge integration. Here we assess the role of these factors in the application of TEK in the Torres Strait Islands, Australia, where commercial and subsistence fisheries are fundamental to the Indigenous Melanesian culture and livelihoods. In 2009 we surveyed fishery managers and scientists who revealed that TEK had only been recently and sparingly applied in four fisheries (turtle, dugong, lobster, and hand collectables), and only two of the seven species concerned had a combination of depleted stocks, low SMK, and high community ownership. Instead, comanagement characteristics and the cultural value of species were the primary determinants of TEK application. We suggest that turtles and dugong are cultural keystone species that simultaneously provide important ecosystem services to both islanders' livelihoods and international conservation interests. Combined with their ecological scale these species have catalyzed comanagement between indigenous and government stakeholders, precipitating the application of TEK in other fisheries of lesser cultural importance. We discuss modifications to governance required to enable knowledge integration to evolve further through adaptive comanagement, and its role in enhancing fisheries management and thus the resilience of the Torres Strait social-ecological system. Our study highlights the potential utility of cultural keystone species in stimulating cross-cultural resource governance in developed economies such as Australia.