An assessment of vessel traffic patterns in the Northwestern Hawaiian Islands between 1994 and 2004.

On June 15, 2006, the United States President George W. Bush signed a proclamation that established the largest coral reef marine reserve in the world, the Northwestern Hawaiian Islands Marine National Monument (NWHI MNM). The NWHI MNM protects a chain of islands and atolls that encompass approximately 360,000 km 2 , including 11,650 km 2 of relatively undisturbed coral reef habitat that support more than 3000 species, a quarter of which are endemic (NOAA, 2006). To evaluate the attainment of the Monument's management goals through time, baseline information was presented on the historic and recent distributions and characteristics of natural resources, environmental conditions, and anthropogenic activities in the NWHI. Although these studies were abundant enough to merit an entire issue of Atoll Research Bulletin (DiNardo and Parrish, 2006), they did not assess the potential threats posed by maritime traffic, an important anthropogenic activity that could significantly impact the protected marine resources of the NWHI. To date, documented vessel impacts to coral reefs range from physical damage caused by running aground the magnitude and spatial distribution of these threats to the NWHI was unknown because of the paucity of information on vessel traffic patterns there. Due to the size and remoteness of the NWHI, only anec-dotal information regarding the activities and attributes of maritime traffic was previously available. Although commercial and research activities occurred in the NWHI for approximately a century (Grigg, 2006; Pooley and Pan, 2006), no quantitative estimation of vessel activity was reported. Unlike some marine management areas adjacent to the continental United States, the NWHI MNM has not had access to an automatic identification system (AIS) or radar array to facilitate the tracking and identification of vessel traffic and provide information on past or present vessel activity (Sean Corson, NWHI MNM, personal communication). The aim of this paper was to provide a base-line of recent activity and identify high traffic corridors, the location of vessels and their attributes in the current boundary of the NWHI MNM from 1994 to 2004. This study represents the first effort to provide a quantitative estimation of vessel traffic to inform management strategies of the MNM related to this anthropogenic activity. Spatial patterns and characteristics of vessel traffic in the Northwestern Hawaiian Islands were examined from Janu-A grid with 0.2° by 0.2° cells of the NWHI was created between 35° N, 175° E, 15° N, and 155° W in a non-projected geographic coordinate …