Coastal Impacts, Adaptation, and Vulnerabilities - Climate ...

56 Coastal Impacts, Adaptation, and Vulnerabilitieswill increase net anthropogenic nitrogen inputs to coastal waters, thereby increasing eutrophicationand hypoxia. Climate change, especially warming, may also make systemsmore susceptible to development of hypoxia through enhanced water column stratification,decreased solubility of oxygen, and increased metabolism and mineralizationrates. High-precipitation storms, which are on the increase (see Chapter 2 section 7 thisreport), increase stratification and organic matter flushed into estuarine and coastal systemsfrom the watershed; algal blooms can result from the nutrient pulses they injectinto estuarine and coastal ecosystems (Paerl et al., 2006a) and massive hypoxia can betriggered by such events (Justic et al., 2007; Paerl et al., 2006b). For the Mississippi Riverbasin associated with the northern Gulf of Mexico seasonal dead zone, climate predictionssuggest a 20 percent increase in river discharge (Miller & Russell, 1992) that wouldlead to elevated nutrient loading, a 50 percent increase in primary production, and expansionof the oxygen-depleted area (Justic et al., 1996). All factors related to climatechange will progressively lead to an onset of hypoxia earlier in the season and longerperiods of hypoxia over time (Boesch et al., 2007)Figure 3-3 Overall eutrophic condition of the nation’s estuaries and change. Source: Bricker et al.,2007.