With the aim of making up for the lack of public administration tools that offer immediate, centralized and georeferenced information on discharges and the state of chemical pollution in Galician coastal waters, the cartographic viewer managed by the Ecotoxicology group of the University of Vigo, Ecotox, directed by professor Ricardo Beiras, began operating in 2013. At present, both the scientific community and society in general have access through the viewer to information on chemical pollution on metals, hydrocarbons and ecotoxicity tests on the Galician coast, from 1997 to the present, grouped in layers, by five-year periods. Scientific publications and reports on marine pollution on the Galician coast, as well as works not published by the Ecotox group itself, are the two sources from which the data used by the viewer comes, which can be accessed through the research team’s web portal. Integrated into a spatial data infrastructure, the viewer is providing both the scientific community and society in general with information on the chemical state of coastal waters using the guidelines set out in the monitoring programme of the Ospar convention on the protection of the marine environment of the Northeast Atlantic”, explains Raimundo Blanco, a researcher at Ecotox, who points out that today online georeferenced information is replacing maps and is part of our daily lives, from mobile phones to car navigation systems.
Once the user accesses the Ecotox web portal, they can enter directly through the ‘access the viewer’ section or go to the menu, ‘geoportal-cartographic viewer’. In this case, on the cartographic viewer page, the user finds a description of the data and the criteria that are being used in the viewer. The viewer has three areas: the map; the upper navigation panel and the side panel of layers, which contains the layers with the pollutants and their legend. On the map, the information is presented in the form of colored points, with a scale that goes from blue (best state) to red (worst state). In addition, by clicking on each point (with the identify tool in the upper panel) the numerical data is accessed.
Less lead pollution and more sewage in the estuaries
After several years of operation of the viewer, in which it was possible to compile a good number of scientific publications and reports on marine pollution on the Galician coast, the Ecotox researcher points out that “although it is a bit risky”, it could be stated as a conclusion about the environmental state of the Galician coast, that globally the situation, in relation to chemical pollution of industrial origin in the estuaries has improved. “However, there are worrying cases, such as lead pollution in the Vigo estuary. This can be seen when comparing the layers with older data with the most recent, verifying that the number of red dots decreases”, details Ricardo Beiras.
In the case of the situation regarding microbiological pollution by sewage, on the contrary, not only is it not improving, but it is increasingly common that seafood cannot be marketed for this reason. “However, the information available in the viewer on the subject of microbiological pollution is very limited and it is the competent administration that should be in charge”, point out the researchers from the University of Vigo.
Data used
The viewer uses several types of data: those of metal concentrations (cadmium, copper, lead, mercury and zinc), of polycyclic hydrocarbons in sediments and wild rock mussels and ecotoxicity data that come from bioassays with sea urchin larvae, exposed to water and elutriated, aqueous extraction of the sediment. “Mussels are used internationally as coastal pollution monitors and the reasons for their choice are several: they have a wide distribution even in highly polluted places; they are easy to obtain; they have a high water filtration capacity and consequently accumulate pollutants if they are present”, explains Beiras, who emphasizes that the viewer also represents data referring to pollution in sediments, which act as sinks for pollutants and are more stable than water, since they are not affected by meteorological factors or currents.
In the case of bioassays with sea urchin larvae exposed to water and elutriated, the Ecotox researcher explains that this is a biological method to detect the presence of toxic chemical substances in samples and quantify their effect. “Broadly speaking, this technique is based on the fact that the development of sea urchin embryos is inversely proportional to the concentration of chemical pollutants in the environment, thus obtaining a quantitative scale of the degree of contamination/toxicity, without the need to analyze centers of toxic substances that could be present,” explains Blanco.
Source: Duvi (Mª del Carmen Echevarría)
