*3.2.1.4 TELS*

On the other hand, TELS has been intensively studied for organic and inorganic pollutants due to its importance as a fisheries center. Thus, Ref. [42] indicates the presence of PAHs in sediments and oysters of this lagoon, reported PAHs in oyster tissue and the predominance of alkylated compounds of medium and low molecular weight indicating a petrogenic origin attributed basically to off-shore oil activities. This lagoon it is located in front of the main oil wells in the Bank of Campeche were the most intense exploration and exploitation of crude oil takes place.

Another study of PAHs performed on fish tissue from the western zone of TELS, showed that its concentrations exceeded the values maximum recommended by international regulation (greater than 40.0 μg g<sup>−</sup><sup>1</sup> ) for the *Petenia splendida* cichlid fish [1]. In recent years [2] evaluated dissolved PAHs and mention that in Boca del Carmen, were determined high concentrations of PAHs; as well as a bacterial community that degrades very abundant PAHs. This is a clear indication that the lagoon arrive at all times dissolved/dispersed PAHs from oil activities carried out in the Sonda de Campeche.

**11**

**Figure 4.**

*Pollution Issues in Coastal Lagoons in the Gulf of Mexico DOI: http://dx.doi.org/10.5772/intechopen.86537*

The investigations on metals in sediments that have been carried out in three of the main coastal lagoons of the Veracruz state, show significant results: the Cd registered similar concentrations for the TLS and MLS with values of 0.46 and

levels that produce adverse biological effects in sediments [43]. On the other hand,

the highest concentration of Cr was for the TLS with 20.52 μg g<sup>−</sup><sup>1</sup>

for the three lagoons were below the limit of the ERL which is 81 μg g<sup>−</sup><sup>1</sup>

tions for ALS and MLS registered similar values with 13 μg g<sup>−</sup><sup>1</sup>

values for MLS and ALS were 15.77 and 17.49 μg g<sup>−</sup><sup>1</sup>

below the ERL which is 34 μg g<sup>−</sup><sup>1</sup>

respectively, and these values were below the ERL that is 1.2 μg g<sup>−</sup><sup>1</sup>

, while for TLS they recorded lower values (11.42 μg g<sup>−</sup><sup>1</sup>

. They report that Zn showed similar values for ALS and MLS with

. The enrichment of Ni in the surface sedimentary substrate is due to the contribution of urban discharges from urban discharges and industries that are close to the coastal areas where the present study was conducted (**Figure 4**) [1, 44]. Villanueva and Ramirez [6] carried out the determination of Cd, Cr, Ni, Pb and V in sediments of the TLS, collected in seven stations. The concentrations decreased in the following order Cr > Ni > Pb > V > Cd, where the latter has not increased since 2010. Although Cd and Pb did increase in 2012, the determined values did not exceed the ecological criteria of the minimum and maximum adverse conditions for the biota (ERL and ERM), while the levels of Ni decreased compared to 2010, since they have a direct influence of the terrestrial and riparian drainages, which present higher hydrodynamics and a greater mixture due to the salt wedge coming from the sea. Likewise, there were no specific changes in metal concentrations between the years 1985 and 1988, the period in which the Thermoelectric Power Plant was built and started to operate. In the period from 1996 to 2012, the concentrations of Cd, Cr and Pb showed slight increases, while the Ni showed variation. Similarly, Vazquez-Botello et al. [23] performed the analysis of a sedimentary core in this lagoon, which concludes that there is a tendency to increase from the oldest

respectively, and their concentrations were below the ERL

. The Ni was presented with values of 71.80 and 72.26 μg g<sup>−</sup><sup>1</sup>

concentrations of this metal in the three lagoons remained below the ERL which

the lagoons of ALS and MLS respectively, and which are above the ERL which is

*Average concentrations of metals in superficial sediments of coastal lagoons of the Veracruz state.*

,

in

, the concentra-

. The concentrations

respectively. These also stayed

. The Pb showed values for MLS and ALS of 23.37

. The Cu

). The

*3.2.2 Metals*

0.66 μg g<sup>−</sup><sup>1</sup>

and 27.49 μg g<sup>−</sup><sup>1</sup>

55.81 and 56.14 μg g<sup>−</sup><sup>1</sup>

which is 150 μg g<sup>−</sup><sup>1</sup>

is 46.7 μg g<sup>−</sup><sup>1</sup>

20.9 μg g<sup>−</sup><sup>1</sup>
