Chapters authored
The Hazards of Monitoring Ecosystem Ocean Health in the Gulf of Mexico: A Mexican Perspective
Ecological services provided by the Gulf of Mexico constitute vital assets for the socioeconomic development of the USA, Mexico, and Cuba. This ecosystem houses vast biodiversity and significant fossil fuel reserves. However, its ecological stability and resilience have been jeopardized by anthropogenic disturbances. Massive oil spills (Ixtoc-I, 1979; Deepwater Horizon, 2010) caused severe environmental injuries and unveiled the vulnerability of coastal and deep-sea habitats. Baseline and monitoring studies are actions implemented by the Gulf stakeholders to cope with such disturbances. The 3-year monitoring program implemented by Mexico in 2010 to assess the environmental damage caused by the Deepwater Horizon (DWH) event confirmed the void of knowledge on the complexity of physical and biological processes susceptible of being altered by oil spills. Between the pelagic and benthic compartments, the latter proved to be a better option in establishing the baseline concentration and trends of oil compounds. Surficial sediments exhibited an increasing concentration trend of PAH, AH, and trace metals throughout the 3-year monitoring. The macroinfauna and selected biomarkers experienced interannual variability attributed to critical hydrocarbon and trace metal thresholds. Sediment toxicity bioassays added support to the distribution and potential sources of oil contaminants dispersed from the northern gulf toward Mexican waters.
Part of the book: Monitoring of Marine Pollution
Pollution Issues in Coastal Lagoons in the Gulf of Mexico
The coastline of the Mexican Gulf of Mexico is an area of paramount importance. It poses valuable biological and ecological resources such as coastal lagoons, rivers, estuaries, wetlands and swamps. It poses 206 coastal systems including 73 coastal lagoons with high biological richness. Their study shows the physicochemical characteristics and pollution levels into the four more productive lagoons of Tampamachoco, Mandinga, Alvarado in the Veracruz state and Terminos Lagoon in Campeche state, México, have the present characteristics. The lagoons show a wide interval in physiochemical parameters (temperature: 18–32°C, salinity: 11–38 ups, and nutrients: oxygen 1.8–9.0 mg/L, total phosphorus 2.6–123 μM total nitrogen 5–70 μM, and chlorophyll 10–50 mg/m3). All of them oscillated between normal to eutrophication condition. The presence of PAHs and some of the high toxicity as anthracene, and chrysene, as well as naphthalene and its methyl derivatives has been reported. Also, chlorinated hydrocarbons used for agriculture purposes and malaria control (DDT, lindane, endosulfan) have been identified in these lagoons. Metals as Cr, Pb, Ni, Cd, and V among others were recently reported in the lagoons considered in this study. Concentrations of pollutants also show significant variations depending on the time and the type of lagoon, or estuary.
Part of the book: Lagoon Environments Around the World