Proceedings of the 12 th International Coral Reef Symposium, Cairns, Australia, 9-13 July 2012 22a: Cultural, political, and historical dimensions of coral reef management. Development of Indicators for Measuring Effects of Human Activities on U.S. Pacific Coral Reefs Cynthia A. Grace-McCaskey 1, 2 1 Joint Institute for Marine and Atmospheric Research, University of Hawaii at Manoa, Honolulu, HI 96814 2 NOAA Fisheries, Pacific Islands Fisheries Science Center, Honolulu, HI 96814 Corresponding author: Cynthia.Grace-McCaskey@noaa.gov Abstract. Over the past 20 years, it has become increasingly clear that coral reefs are some of the most threatened ecosystems in the world. It is now generally accepted that humans impact reefs in a variety of ways, ranging from fishing and land development to anthropogenic climate change, and current research has begun to examine the intricacies of the relationships between anthropogenic factors and coral reef health. This paper describes current research to develop human dimensions data that can be synthesized with coral reef biophysical data to measure human impacts on coral reefs throughout the U.S. Pacific. Some of the challenges inherent in this research are how to characterize and compare coral reef fisheries across the region using the small amount of available fisheries data while taking into consideration the larger social, political, and historical context in which these fisheries are embedded. While it is important to understand the overarching trends and commonalities across coral reef fisheries so that management strategies can address conservation concerns in a consistent manner, we need to be able to advise managers on ways to incorporate knowledge of local human interactions with coral reef ecosystems and involve the institutions that manage them at a local scale. Key words: Human dimensions, anthropogenic impacts, Reef fisheries, Pacific, Comparative. Introduction Over the past 20 years, it has become increasingly clear that coral reefs are some of the most threatened ecosystems in the world. It is now generally accepted that humans impact reefs in a variety of ways, from fishing to climate change, and current research has begun to examine the intricacies of the relationships between anthropogenic factors and coral reef health (Cinner, et al. 2009; Mora 2008; Williams, et al. 2011; Williams, et al. 2008). For example, studies have focused on the relationships between artisanal fishing and key functional groups of herbivorous reef fish (Lokrantz, et al. 2010), the role of fish markets in driving resource use and reef conditions (Brewer, et al. 2009), and the relationship between coral disease and human population size (Aeby, et al. 2011a). These studies are extremely important because coral reefs provide critical resources to millions of people throughout the world (Cinner 2010; Kronen, et al. 2010; Wilkinson 2002). In order for humans to continue to use the reef resources on which they depend, we must find ways to discriminate among stressors so that appropriate and effective management strategies can be developed. One approach that has been used by researchers to examine the relationships between anthropogenic factors and coral reef health is to compare data from several islands and reefs that occur across a wide range of biological, climatic, and anthropogenic conditions. Islands suitable for these “natural experiments” are found in the Pacific region, including the Hawaiian Islands, the Line Islands, and several other US-affiliated islands (e.g., Commonwealth of the Northern Mariana Islands, CNMI; Guam, American Samoa). Researchers have begun to describe the variation that exists throughout this region’s reefs in terms of fish assemblages (Friedlander and DeMartini 2002; Stevenson, et al. 2007; Williams, et al. 2011; Williams, et al. 2008), coral disease (Aeby, et al. 2011a; Aeby, et al. 2011b), and overall reef community structure (Sandin, et al. 2008). Several of these studies have examined the variation in ecological components in terms of human population or population density, using those data as proxies for an overall level of anthropogenic impact. As part of an ongoing collaboration between the Coral Reef Ecosystem Division (CRED) and the Human Dimensions Research Program at the NOAA Fisheries’ Pacific Islands Fisheries Science Center, and the Scripps Institution of Oceanography’s Center for Marine Biodiversity and Conservation, researchers are moving beyond using human population size as a proxy for human impacts toward a more in-depth examination of human-reef relationships. A diverse array of information on human activities and other social data are being compiled to be analyzed in