The largest accidental marine oil spill (4.9 million barrels) in the Gulf of Mexico (GoM) seabed (1600 m) caused by the sinking of the Deepwater Horizon oil rig in 2010, put to the test once again the resilient capaci...The largest accidental marine oil spill (4.9 million barrels) in the Gulf of Mexico (GoM) seabed (1600 m) caused by the sinking of the Deepwater Horizon oil rig in 2010, put to the test once again the resilient capacity of the pelagic and benthic realms of this Large Marine Ecosystem. Many are the ecological services provided by its waters (fisheries, tourism, aquaculture and fossil fuel reserves) to neighboring countries (US, Mexico and Cuba). However, the unprecedented volumes of hydrocarbons, gas and chemical dispersants (Corexit) introduced in the system, represent ecological stressors whose deleterious effects are still the subject of civil claims and scientific controversy. Presumably, the short scale effects were confined to the Gulf’s northeastern shallow waters, and the combined actions of weathering, biodegradation, and oil recovery left the system almost under pre-spill conditions. Unfortunately, surface and subsurface oil plumes were detected in the spill aftermath, and their dispersion trajectories threatened Mexico EEZ. Surface oil slicks were detected in the pristine waters of northern Yucatán, while subsurface oil plumes from the Macondo’s well blowout were dangerously advancing southwest towards key fishing grounds in the northwestern GoM. This disaster prompted the Mexican government to implement an ambitious ocean monitoring program adopting a bottom-up approach focused on building a base line for more than 42 physicochemical and biological variables for water, sediment and biota from the continental shelf-slope region of the NW GoM. Technological constraints have precluded systematic observations in the vast Mexican EEZ that could discriminate natural variability and oil seep emissions from antropic disturbances. Therefore, preliminary risk analyses relied on seasonal and historical records. Two years of field observations revealed subtle environmental changes in the studied area attributed to antropic disturbances. Waters maintained oligotrophic conditions and zooplankton and benthic infaunal biomass were also poor. Biomarkers in sediments and biota did not exceed EPA’s benchmarks, and sediment’s fingerprinting (δ13C) indicated marine carbon sources. Geomarkers revealed an active transport from the Mississippi towards the NW GoM of phyllosilicates bearing a weathered oil coating. Consequently, shelf and slope sediment toxicity begins to show an increasing trend in the region. The complexity of hydrocarbons bioaccumulation and biodegradation processes in deep waters of the GoM seems to indicate that meso-and large-scale observations may prove to be essential in understanding the capacity of the GoM to recover its ecological stability.展开更多
The reassessment of ocean economy contribution of nations has become a new strategy for frontier states adjacent to the coastal region for the improvement of their position in the efficiency frontier curve. The contin...The reassessment of ocean economy contribution of nations has become a new strategy for frontier states adjacent to the coastal region for the improvement of their position in the efficiency frontier curve. The continuity of a coastal state to remain a leader in the production and efficiency frontier curve of modem day development will thus depend on their ability to sustainably develop their most strategic economic resource base such as the ocean economy. The major economic bases include sustainable fishing, offshore oil field developments, offshore biodiversity development and marine biotechnology, offshore mining of manganese nodules, offshore wind farm potentials, international shipping （marine transport） and adjoining corridor development, ship dry docking potentials, marine renewable energy as well as other potentials outlined in the definition of African Union strategy for the development of her blue economy. Adopting the regression analysis and analysis of variance analytical tools, the study found that about 90% association exist between the GDP （gross domestic product） of the West African state （Nigeria） and her GDP. It equally found that offshore oil and gas energy sector more significantly impact on the GDP of Nigeria than other ocean economy business clusters. Given the various contributing marine environment business cluster used in the work, the model depicting the influence of the ocean economy of Nigeria is： Y = 2295334779895 - 294733（1 ＋ 3436995749 - 59276863（2 ＋ e.展开更多
文摘The largest accidental marine oil spill (4.9 million barrels) in the Gulf of Mexico (GoM) seabed (1600 m) caused by the sinking of the Deepwater Horizon oil rig in 2010, put to the test once again the resilient capacity of the pelagic and benthic realms of this Large Marine Ecosystem. Many are the ecological services provided by its waters (fisheries, tourism, aquaculture and fossil fuel reserves) to neighboring countries (US, Mexico and Cuba). However, the unprecedented volumes of hydrocarbons, gas and chemical dispersants (Corexit) introduced in the system, represent ecological stressors whose deleterious effects are still the subject of civil claims and scientific controversy. Presumably, the short scale effects were confined to the Gulf’s northeastern shallow waters, and the combined actions of weathering, biodegradation, and oil recovery left the system almost under pre-spill conditions. Unfortunately, surface and subsurface oil plumes were detected in the spill aftermath, and their dispersion trajectories threatened Mexico EEZ. Surface oil slicks were detected in the pristine waters of northern Yucatán, while subsurface oil plumes from the Macondo’s well blowout were dangerously advancing southwest towards key fishing grounds in the northwestern GoM. This disaster prompted the Mexican government to implement an ambitious ocean monitoring program adopting a bottom-up approach focused on building a base line for more than 42 physicochemical and biological variables for water, sediment and biota from the continental shelf-slope region of the NW GoM. Technological constraints have precluded systematic observations in the vast Mexican EEZ that could discriminate natural variability and oil seep emissions from antropic disturbances. Therefore, preliminary risk analyses relied on seasonal and historical records. Two years of field observations revealed subtle environmental changes in the studied area attributed to antropic disturbances. Waters maintained oligotrophic conditions and zooplankton and benthic infaunal biomass were also poor. Biomarkers in sediments and biota did not exceed EPA’s benchmarks, and sediment’s fingerprinting (δ13C) indicated marine carbon sources. Geomarkers revealed an active transport from the Mississippi towards the NW GoM of phyllosilicates bearing a weathered oil coating. Consequently, shelf and slope sediment toxicity begins to show an increasing trend in the region. The complexity of hydrocarbons bioaccumulation and biodegradation processes in deep waters of the GoM seems to indicate that meso-and large-scale observations may prove to be essential in understanding the capacity of the GoM to recover its ecological stability.
文摘The reassessment of ocean economy contribution of nations has become a new strategy for frontier states adjacent to the coastal region for the improvement of their position in the efficiency frontier curve. The continuity of a coastal state to remain a leader in the production and efficiency frontier curve of modem day development will thus depend on their ability to sustainably develop their most strategic economic resource base such as the ocean economy. The major economic bases include sustainable fishing, offshore oil field developments, offshore biodiversity development and marine biotechnology, offshore mining of manganese nodules, offshore wind farm potentials, international shipping （marine transport） and adjoining corridor development, ship dry docking potentials, marine renewable energy as well as other potentials outlined in the definition of African Union strategy for the development of her blue economy. Adopting the regression analysis and analysis of variance analytical tools, the study found that about 90% association exist between the GDP （gross domestic product） of the West African state （Nigeria） and her GDP. It equally found that offshore oil and gas energy sector more significantly impact on the GDP of Nigeria than other ocean economy business clusters. Given the various contributing marine environment business cluster used in the work, the model depicting the influence of the ocean economy of Nigeria is： Y = 2295334779895 - 294733（1 ＋ 3436995749 - 59276863（2 ＋ e.
