Physico-chemical, biological and geological study of an underwater volcano in a degassing stage: Island of El Hierro

El objetivo principal del proyecto “Physico-chemical, biological and geological study of an underwater volcano in a degassing stage: Island of El Hierro”, (VULCANO-II) es estudiar, desde un punto de vista totalmente interdisciplinar, la fase de desgasificación activa del único volcán submarino monitoreado desde su nacimiento en aguas españolas. De esta forma, se pretende además, dar continuidad a los estudios multidisciplinares realizados sobre el volcán submarino de la isla de El Hierro en el contexto del proyecto del Plan Nacional VULCANO-I, (CTM2012-36317) y VULCANA (Vulcanología Canaria Submarina, IEO). Para ello, se realizará la monitorización de las propiedades físico-químicas, biológicas y geológicas del proceso eruptivo submarino de la isla de El Hierro y otros puntos sensibles, como el volcán de Enmedio entre Gran Canaria y Tenerif

Inferring Class of organisms in the Central-East Atlantic from eco-toxicological characterization

All marine organisms bio-accumulate metals and trace elements in a different way, and there are great differences depending on the level of taxonomic classes. A total of 660 samples of 22 species of different taxonomic class types have been used for this study, all samples were measured with atomic emission spectrometry with inductively coupled plasma (ICP-OES), the mammalian class has the highest concentration of Zn (17.215 ± 13.750 mg/kg w.w) and of Fe (86.215 ± 49.495 mg/kg w.w), these values being much higher than the other classes, and the cephalopods have the highest concentration in heavy metals such as Cd (0.963 ± 1.056 mg/kg w.w) and Pb (0.466 ± 0.909 mg/kg w.w). All the classes presented significant differences among each other, each class presents some ranges of each metal different to the other classes. Based on the present study, the ecological preferences and the taxonomical classification give differential metal content patterns for marine organisms, thus showing the importance of this study for the preparation of environmental plans to check the state of the marine ecosystem

Metal Content in Small Pelagic Fish in the North-West Africa

This work presents the analysis of 20 heavy metals concentrations (Al, B, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Ni, Pb, Sr, V and Zn) in 80 muscle samples of two species widely consumed by humans, such as the European sardine (Sardina pilchardus) and the blue jack mackerel (Trachurus picturatus). Both species have similar metal concentrations, with significant differences in Ba, Ca, Ni, Pb and Mn. Most of the relations between the concentration of metals and the weight of the individuals were negative. All concentrations of toxic heavy metals were lower (than the legislated maximum limits for consumption S. pilchardus: 3.983 mg/kg Al, 0.016 mg/kg Cd, 0.047 mg/kg Pb, and T. picturatus: 5.484 mg/kg Al, 0.011 mg/kg Cd, 0.040 mg/kg Pb). The results were compared with available information with available information for the species. Higher metallic content found in studies from close areas of the African coast, could be due to the influence of the upwelling and to the dust from the the Saharan desert

Seasonal and ontogenic variations of metal content in the European pilchard (Sardina pilchardus) in northwestern African waters

Marine fishes are exposed to great human-induced alterations due to the indiscriminate discharges into the sea, increasing marine pollution. For this study, 324 specimens of Sardina pilchardus from the Canary Islands were analized during a period of 2 years (June 2016 to May 2018). The concentration of 11 metals and trace elements (Al, B, Cd, Cr, Cu, Fe, Li, Ni, Pb, V and Zn) was determined in each individual using the Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) technique. Statistical analyses were carried out considering the following factors: oceanographic season, maturity of the gonads in the seasons, size of the specimens. Sardina pilchardus specimens captured in the hot season presented higher Ni, Li and Pb levels than the specimens caught in the cold season. Immature specimens had higher concentration in more metals than the mature specimens. This fact may be due to the fact that these specimens require a much higher metabolic rate due to their growth and do not detoxify like mature specimens. Significant differences were found in the concentration of metals in all the analyzes performed

Development stage and season influence in the metal content of small pelagic fish in the North-West Africa

Marine organisms are exposed to great changes caused by man due to discharges into the oceans, so the study of marine pollution is of great value for each ecosystem. For this study, 963 specimens of pelagic fish have been collected, of which 345 are Scomber colias, 294 are Trachurus picturatus and 324 are Sardina pilchardus, it was wanted to study the development and ontogeny in the three species observing if there were variations in their metallic content. The study covered a total of 2 years, from June 2016 to May 2018.16 samples of each species were studied each month, during the 2 years of sampling, from the samplings carried out by the Canary Islands Oceanographic Center of the Spanish Institute Oceanography (COC-IEO) in the markets of the Island of Tenerife. The concentration of 11 anthropic metals was determined in each sample using the Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) technique. Statistical studies were carried out with factors such as the oceanographic season, and the level of maturity of the gonads. S. colias was the species that presented the highest concentration in a greater number of metals. S. pilchardus presents higher concentration in Cu, Li and Zn, in the warm season. These are metals of a very anthropic character on coasts; This species tends to get closer to the coasts compared to the other two and is the cause of its higher concentration in these metals due to the influence of pollution linked to the coast. The immature specimens of the three species had a higher concentration in more metals than the mature specimens

Influence of Biometric and Seasonal Parameters on the Metal Content of Scomber colias in Northwestern African Waters

Studies of the content of heavy metals and trace elements in fish and other marine organisms are of great importance to know the state of the marine ecosystem. This study has been carried out in northwestern African waters, Scomber colias being the target species, sampling a total of 345 specimens over 2 years. For the determination of metals and trace elements (Al, B, Cd, Cr, Cu, Fe, Li, Ni, Pb, V, and Zn) in the muscle, the ICP-OES (inductively coupled plasma optical emission spectrometry) was used. In the statistical study, the factors (oceanographic and maturity in the seasons, size of the specimens) were used. The samples sampled in the cold season that had high concentrations of metals may be due to the influence that African upwelling has on the Canary Islands. The metallic contents of our samples are lower than those found in the studies in Mauritania and Morocco due to the greater influence that upwelling has in these areas

Ontogenic and seasonal variations of metal contents in a small pelagic fish (Trachurus picturatus) in northwestern African waters

Marine organisms are exposed to great changes induced by human beings due, among others, to discharges into the oceans, increasing marine pollution. For this study, 294 specimens of Trachurus picturatus from the Canary Islands were analyzed during a period of 2 years. The concentration of 11 anthropic metals and trace elements was determined in each individual using the Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) technique. Statistical analyses were carried out considering the following factors: oceanographic season, maturity of the gonads, size of the specimens, season. Immature specimens had higher concentration in more metals than the mature specimens. This fact may be due to the fact that these specimens require a much higher metabolic rate due to their growth and do not detoxify like mature specimens

Inferring trophic groups of fish in the central-east Atlantic from eco-toxicological characterization.

The marine organisms are exposed to great human-induced alterations due to the indiscriminate discharges into the sea, which is why the study of marine pollution is of great value for each ecosystem. Each organism bioaccumulates distantly the heavy metals and trace elements in its organism. Because of this it is possible to classify different groups of fish according to their feeding with the content of these metals. Ten fish species were grouped considering their trophic level and habitat ecology (benthic predators, herbivores, omnivores, pelagic predators and superpredator) and analyzed for its metal content. Statistically significant differences were found among all the fish groups, with the Superpredator group containing the highest concentrations in all metals, mainly Fe (103.751 ± 92.151 mg/kg) and Al (28.908 ± 21.221 mg/kg). Therefore, this study highlights that the selection of the species taking into account feeding and habitat partitioning must be carefully considered being crucial to identify fish groups as biological indicators of marine pollution