How does rising atmospheric CO2 affect marine organisms?

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Sediment Load As a Cause of Coral Bleaching - Summary
High rates of sedimentation have been conclusively demonstrated to lead to coral bleaching (Wesseling et al., 1999); and most historical increases in sedimentation rates are clearly human-induced.  Umar et al. (1998), for example, list such contributing anthropogenic activities as deforestation, agricultural practices, coastal development, construction, mining, drilling, dredging, and tourism.  Nowlis et al. (1997) also discuss how land development can increase the risk of severe damage to coral reefs by sediment runoff during storms.

Taken together, these findings suggest that the natural course of human population growth and societal and economic development over the period of the Industrial Revolution may have predisposed coral reefs to ever-increasing incidences of bleaching and subsequent mortality via a gradual intensification of near-coastal riverine sediment transport rates.  In the absence of this phenomenon, corals may be much less susceptible to other environmental stresses, such as disease or extremes of solar radiation and water temperature.  Hence, the apparent upward trend in coral bleaching over the past several decades, which is often attributed to global warming, may well be due to this much broader range of human activities that directly impact the affected corals' immediate environment.

Nowlis, J.S., Roberts, C.M., Smith, A.H. and Siirila, E.  1997.  Human-enhanced impacts of a tropical storm on nearshore coral reefs.  Ambio 26: 515-521.

Umar, M.J., McCook, L.J. and Price, I.R.  1998.  Effects of sediment deposition on the seaweed Sargassum on a fringing coral reef.  Coral Reefs 17: 169-177.

Wesseling, I., Uychiaoco, A.J., Aliņo, P.M., Aurin, T. and Vermaat, J.E.  1999.  Damage and recovery of four Philippine corals from short-term sediment burial.  Marine Ecology Progress Series 176: 11-15.