g. Ban et al., 2014 and Cheung see more et al., 2013) but also performing a modeling study based on a subregion of Southeast Asia (Raja Ampat, Papua, in the Indonesian archipelago – see Box 1). Specifically, we used an Ecopath with Ecosim model parameterized for the Raja Ampat

reefs (Ainsworth et al., 2008), which we extended to include responses of space-limited algae. Then we modeled the effect a progressive 0–100% reduction in extent of coral cover will have on reef community structure, and the effect of these changes on fishery production (see Box 1). This study demonstrates how reef degradation will affect reef fishery production, and thus local livelihoods and the national economy. As a first approximation for identifying priorities for immediate management response, we constructed a simple model that ranks areas according selleckchem to cumulative pressures and potential user conflicts. To approximate the intensity of human impacts on tropical coastal seas around the world we used the ‘focalmean’ tool in ArcCatalog to extrapolate a population proximity index for each of the grid cells in the continental shelf region of the tropics. ‘Focalmean’ calculates a new value for each grid cell

in an existing grid, based on the value of surrounding grid cells. For our analyses, we used a circular Terminal deoxynucleotidyl transferase region around each grid cell, which extended out to a radius of 100 grid cells. This approximated a focal mean radius of about 93 km at the equator. We created a source grid for our focal mean calculations by combining the LandScan grid with the continental shelf grid. Each of the grid cells in the shelf region of the source grid had a value of 0, and all of the terrestrial grid cells had the corresponding population count information from LandScan. We masked out all land grid cells in the resulting focal mean grid. The shelf region greater than 100 km from a coast received

a population proximity index score of zero, since those areas were assumed to receive negligible direct impacts from urbanization. We acknowledge that certain ocean-based activities (e.g. offshore mineral extraction) will have impacts not captured by our approach. The 100 km wide coastal strip comprises 21% of all land, and is occupied by over 2.6 billion people (Fig. 1) at densities from <20 km−2 to >15,000 km−2, and an average density (97 km−2) over twice that of inland regions (41 km−2). Over half these people (1.36 billion) live on tropical coasts (just 7% of all land) at even higher densities (145 km−2). Tropical coasts hold 9 of 19 coastal megacities (>10 million people each), and are most densely populated (mean of 198 km−2) in South and Southeast Asia (Balk, 2011 and von Glasow et al., 2013).