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

First records of Kinorhyncha from the Gulf of California: horizontal and vertical distribution of four genera in shallow basins with CO2 venting activity

The Wagner and Consag Basins, in the northern end of the Gulf of California are characterized by active CO2 gas vents. This venting activity causes a decrease in the pore water pH compared to other marine environments and the acidification of the bottom water is expected to affect the organisms that inhabit the sediments. In this study, we present the first records of four genera and ten “working species” of the phylum Kinorhyncha in Mexico. We also analyzed their horizontal and vertical distribution. Samples were collected at 40 soft bottom sites on board of the R/V “El Puma” (WAGNER-02 Expedition) during July-August 2010 with a Smith McIntyre grab and a syringe corer. At each station physicochemical variables were measured including pore water pH. In this study, Kinorhyncha represented 2.64% of the total meiofauna and it ranked fourth in dominance after Nematoda, Copepoda, and Polychaeta. Kinorhynchs densities ranged from zero to 24.05 ind.10 cm-2. We encountered a total of two families, four genera and ten “working species” of kinorhynchs. The family Pycnophyidae was represented by two genera Pycnophyes (two “working species”) and Kinorhynchus (five ”working species”) and the family Echinoderidae, two “working species” of the genus Echinoderes and one “working specie” of Fissuroderes were present. Kinorhynchs were mainly concentrated in the upper layers, with about 84% of the individuals present in the first four centimeters. This is the first ecological study of the phylum Kinorhyncha in Mexico and in a CO2 venting - low pH environment, registering also for the first time some data on the pH tolerance of these four kinorhynchs genera