**1. Introduction**

 Due to its geological origin, the Gulf of Mexico (GoM) represents an ideal semiclosed basin for the accumulation of fossil deposits of oil and gas [1]. This unique attribute has historically exposed the Gulf to natural seepage of oil and gas from the seabed. These natural emanations have been recorded in several sectors of the Gulf and represent a significant source of contamination [2, 3]. However, in recent times, the stability and resilience of this large marine ecosystem have been tested by severe anthropogenic disturbances. Massive spills of crude oil produced by the decontrol

of the Ixtoc well-I in the Campeche Sound in 1979 and, most recently, in the well Macondo caused by the collapse of the Deepwater Horizon (DWH) oil platform off the coast of Louisiana in 2010 are examples that have caused severe damage to the environmental health of the Gulf [4, 5].

 In April 20, 2010, a severe accident occurred at the oil platform DWH about 50 nautical miles southeast of the Mississippi River Delta, in the north of the GoM. This unfortunate event caused the loss of 11 lives and caused a spill of 4.9 million barrels of crude oil from the Macondo's well at 1650 m of depth. Several authors already considered this environmental catastrophe as the greatest disaster in the oil industry of the United States [6, 7].

The British firm British Petroleum (BP), responsible for the operation of the DWH platform, implemented a series of immediate emergency actions to mitigate somewhat the damage to the marine ecosystem, caused by the leakage of roughly 12,000–19,000 barrels of oil per day. Such activities involved the direct recovery of liquid hydrocarbons, the selective burning of oil slicks in surface waters, and the use of 1.85 million gallons of chemical dispersants (Corexit®), both on the surface and in the seabed [8, 9]. The hydrographic conditions prevailing in the GoM during the summer of 2010, combined with the onset of hurricane Alex in July, helped to contain the black tide of crude oil near the Mississippi Canyon. The initial oil slick trajectories were toward the northeastern sector of the Gulf. The satellite images obtained by the National Oceanic and Atmospheric Agency (NOAA), later supplemented with the ocean circulation models generated by the Consortium of Universities of the Northern Gulf, confirmed those trajectories, with ensuing filaments flowing toward the Texas coast. Similarly, through the use of remote sensors, it was possible to identify traces of crude oil trapped by the Eddy Franklin Gyre, a critical component of the loop current; some of these images also revealed small traces of crude oil in the waters of Mexico's exclusive economic zone (EEZ), reaching the north of the Yucatan Peninsula [10].

 Without a doubt, the volume of crude oil spilled, and the quantity of chemical dispersant employed, constituted a severe alteration to the ecological balance and the environmental health of the GoM. The precise calculation of the volume of spilled oil, the trajectory of the oil stains in subsurface and surface waters, as well as the degradation rates of crude oil and its derivative compounds remain controversial topics among specialists. This problem is magnified by the chemical complexity of the crude oil. Fossil hydrocarbons include up to 17,000 organic compounds [11], each with its solubility, volatility, and density properties, as well as its different degrees of toxicity in marine biota and humans.

 According to the American agencies, NOAA and the Environmental Protection Agency (EPA), a significant percentage of crude oil was recovered, and the rest was burned or lost by evaporation. However, there was overwhelming evidence of the severe damage caused to the coastal areas in the northeastern GoM. Marshlands, swamps, and coastal lagoons, which represent vital breeding grounds for wildlife fauna, were severely affected by the invading black tide. In the face of this dramatic environmental setting, Mexico was also forced to implement emergency measures focused on the early detection of crude oil slicks or tar balls within its vast exclusive economic zone (EEZ) in the GoM. Given the prevailing surface water circulation and the high connectivity among the different sectors of the Gulf, there was potentially a risk of oil pollutants from Macondo's entering Mexican waters. It was then necessary as a government to maintain a monitoring plan of the general oceanographic conditions in Mexican waters.

*The Hazards of Monitoring Ecosystem Ocean Health in the Gulf of Mexico: A Mexican Perspective DOI: http://dx.doi.org/10.5772/intechopen.81685* 
