Tracking Coastal Hypoxia:Tracking Coastal Hypoxia:Learning from the Evidence Learning from the Evidence
for Remediationfor Remediation
Tracking Coastal Hypoxia:Tracking Coastal Hypoxia:Learning from the Evidence Learning from the Evidence
for Remediationfor RemediationRobert J Díaz
http://www.vims.edu/deadzone/
Robert J Díaz
http://www.vims.edu/deadzone/
Why is Hypoxia a problem?Why is Hypoxia a problem?
Seriousness of low Dissolved Oxygen is best expressed by motto of American Lung Association:
““When You Can’t Breathe, When You Can’t Breathe, Nothing Else Matters.”Nothing Else Matters.”
Spread of HypoxiaSpread of HypoxiaIn the 1960s the number of systems with reports of
hypoxia-related problems started to increase.
Diaz & Rosenberg 2008Updated by Diaz et al. 2010
www.wri.org/project/eutrophication
Spread of HypoxiaSpread of HypoxiaBy the 1980s there was an explosive increase in the number of
hypoxic systems.
Diaz & Rosenberg 2008Updated by Diaz et al. 2010
www.wri.org/project/eutrophication
Spread of HypoxiaSpread of HypoxiaBy the 1990s and 2000s most estuarine and marine systems in
close proximity to population centers had reports of hypoxia/anoxia.
Diaz & Rosenberg 2008Updated by Diaz et al. 2010
www.wri.org/project/eutrophication
Oxygen Minimum Zones (<0.5 ml/l) Touch 1,148,000 kmOxygen Minimum Zones (<0.5 ml/l) Touch 1,148,000 km22 of Seafloor Along Continental Margins.of Seafloor Along Continental Margins.
Oxygen Minimum Zones (<0.5 ml/l) Touch 1,148,000 kmOxygen Minimum Zones (<0.5 ml/l) Touch 1,148,000 km22 of Seafloor Along Continental Margins.of Seafloor Along Continental Margins.
31% in eastern Pacific Ocean
59% in Indian Ocean
10% in southeastern Atlantic
31% in eastern Pacific Ocean
59% in Indian Ocean
10% in southeastern Atlantic
Helly & Levin 2004Helly & Levin 2004
Recovered with Nutrient ManagementRecovered with Nutrient Management
58 systems have responded positively.
