, 2009). Soil and water conservation programs in China were first legislated in the 1950s following concern about local agricultural and industrial productivity and flooding downstream (Shi and Shao, 2000). Implementation at large spatial scales (e.g. 0.92 M km2 of land terracing, tree and grass planting, and construction of selleck compound sediment trapping dams), mostly in the Yellow and Yangtze basins, has reduced sediment fluxes to coastal waters by an estimated 11.5 Gt during 1959–2007 (Chu et al., 2009). Terrestrial fluxes of N and P to coastal waters have been reduced following management of point sources, such as waste water treatment plants, phosphate mines and P-detergents (Boesch, 2002 and Cloern, 2001) (Tables 1c and 2). For example,

regulation has reduced the contributions from waste water treatment plants and industrial discharges to total annual average N and P loads to the Danish coast from ∼50% to <10%, and from 59% to ∼20%, respectively, over 14 years (Carstensen et al., 2006). The check details nutrient regulation in Denmark followed lobster mortality in coastal waters in the 1980s which was attributed to algal blooms and hypoxia induced by agricultural nutrient run-off (Windolf et al., 2012). Similar declines in nutrient loads from point sources have resulted in reductions in coastal nutrient and chlorophyll a (chl a)

concentrations ( Greening and Janicki, 2006), enhanced benthic irradiance ( Greening and Janicki, 2006), seagrass recovery ( Tomasko et al., 2005), and concomitant decline in macroalgae ( Cardoso et al., 2010 and Vaudrey et al., 2010), including on coastal coral reefs ( Laws and Allen, 1996 and Smith et al., 1981). Further recovery, including to a coral-reef dominated state, may be partly constrained by nutrient sources other than point sources ( Hunter and Evans, 1995), as well as obscured by increases in human population, changes in diffuse sources and

variation in freshwater discharge ( Williams et al., 2010). Reducing diffuse source loads becomes increasingly important where point source discharges comprise only a small percentage of the total N and P loads, such as in the Great Barrier Reef (GBRMPA, 2009). Major recent reviews provide recommendations to reduce excessive or inappropriate input of N and P from diffuse sources such as agriculture, selleck screening library fossil-fuel and animal husbandry (Canfield et al., 2010, Elser and Bennett, 2011, Galloway et al., 2008 and Vitousek et al., 2009). Deliberate management of agricultural diffuse pollution has contributed to reducing nutrient fluxes to coastal waters in Denmark (Windolf et al., 2012) and The Netherlands (Duarte et al., 2009) within decades (Tables 1c and 2). Moreover, decreasing nutrient fluxes have been measured in several Eastern European rivers, namely the Danube, Daugava, Elbe, Leilupe, Oder and Vistula rivers, in the years following economic decline and associated drop in agricultural subsidies in the early 1990s (Duarte et al., 2009, GEF-UNDP, 2006, Mee, 2001, Pastuszak et al.