Complex organochlorine pesticide mixtures as determinant factor for breast cancer risk: a population-based case–control study in the Canary Islands (Spain)

[EN]All the relevant risk factors contributing to breast cancer etiology are not fully known. Exposure to organochlorine pesticides has been linked to an increased incidence of the disease, although not all data have been consistent. Most published studies evaluated the exposure to organochlorines individually, ignoring the potential effects exerted by the mixtures of chemicals.

Estimating Natural Recharge by Means of Chloride Mass Balance in a Volcanic Aquifer: Northeastern Gran Canaria (Canary Islands, Spain)

[EN]The chloride mass balance method was used to estimate the average diffuse groundwater recharge on northeastern Gran Canaria (Canary Islands), where the largest recharge to the volcanic island aquifer occurs. Rainwater was sampled monthly in ten rainwater collectors to determine the bulk deposition rate of chloride for the 2008–2014 period. Average chloride deposition decreases inwardly from more than 10 g·m−2 ·year−1 to about 4 g·m−2 ·year−1 . The application of the chloride mass balance method resulted in an estimated average recharge of about 28 hm3 /year or 92 mm/year (24% of precipitation) in the study area after subtracting chloride loss with surface runoff.

Comments on Uncertainty in Groundwater Governance in the Volcanic Canary Islands, Spain

[EN]The uncertainty associated with natural magnitudes and processes is conspicuous in water resources and groundwater evaluation. This uncertainty has an essential component and a part that can be reduced to some extent by increasing knowledge, improving monitoring coverage, continuous elaboration of data and accuracy and addressing the related economic and social aspects involved. Reducing uncertainty has a cost that may not be justified by the improvement that is obtainable, but that has to be known to make the right decisions. With this idea, this paper contributes general comments on the evaluation of groundwater resources in the semiarid Canary Islands and on some of the main sources of uncertainty, but a full treatment is not attempted, nor how to reduce it.

Underwater towed video: a useful tool to rapidly assess elasmobranch populations in large marine protected areas

Elasmobranch stock assessment studies are usually made through fisheries surveys data. However, in large marine protected areas (MPAs) the use of destructive techniques must be dismissed in order to avoid population impacts. In 2005, while conducting a marine habitat survey in two marine Special Areas of Conservation (Sebadales de Playa de Inglés and Franja Marina de Mogán) in south Gran Canary Island (Canary Islands, Spain) with underwater towed video (UTV) and underwater visual census (UVC) transects, we recognized the opportunity rose to assess elasmobranch populations through UTV. Number of observed species and specimens, overall field work effort and total surveyed area were determined and compared between methods. Mean observations per day per unit of time (MOPUT) and mean observations per day per unit of surveyed area (MOPUA) were also compared through Mann–Whitney rank sum statistical test (α=0.05). Data analysis demonstrated that UTV is a very useful tool to rapidly assess elasmobranch populations in large MPAs in good visibility underwater environments. It can assess larger areas than UVC with the same effort (statistically significant difference found for the MOPUT; p=<0.001), leading to more observed species (5 vs 2) and specimens (46 vs 3) per day of work, with no loss in resolution power (MOPUA values were not significantly different between UTV and UVC; p=0.104).

Gestión integral en la Playa de Montaña Arena: Análisis y Diagnóstico preliminar

Máster Universitario en Gestión Costera

Homing behaviour of Parablennius parvicornis (Pisces: Blenniidae)

The homing ability of the rockpool fish Parablennius parvicornis was studied at the rocky shore of Gran Canaria (Canary Islands, Spain). Fish were displaced from the original rockpool during low tide to another pool 74 metres away. The return of the first blenny occurs directly after the first tide while one week later 40% of the blennies had returned to the original pool. This paper discusses the homing behaviour of this species. RESUMEN: Se estudian las habilidades de retorno (homing) de la barriguda Parablennius parvicornis en una región de la costa rocosa de la isla de Gran Canaria (Islas Canarias, España). Los peces fueron desplazados desde su charco original, durante la bajamar, a otro charco que distase 74 metros. El retorno de la primera barriguda ocurrió después de la primera marea, mientras que tras una semana habían regresado el 40% de los peces originalmente desplazados. En este artículo se discute el comportamiento de retorno de esta especie

Restoration of Cymodocea nodosa (Uchria) Ascherson seagrass prairies through seed propagation. Germination in vitro, plantlet acclimation and transplanting to natural meadows.

[EN] The seagrass Cymodocea nodosa (Ucria) Ascherson is the most abundant seagrass species in the Canary Islands (Spain), where it forms dense submerged, ecologically relevant communities as stable and protected habitats. As with other seagrasses, concern has arisen due to a decline in the number and extension of the communities as the result of adverse activities in coastal areas. Seed germination and planting are assumed as cost-effective method for restoration. In the frame of the restoration of natural populations of Cymodocea nodosa, pilot experiences not tested so far in the Canary Islands have been carried out to developed in vitro techniques to produce viable seedlings and its transference to the natural environment.

Datos preliminares sobre la reproducción del centollo Maja brachydactyla (Balss, 1922) en condiciones de cultivo en Canarias

[EN] The atlantic spider crab Maja brachydactyla, nowadays overfished, presents good conditions for its production in captivity. In Canary Islands (Spain), under culture conditions, with open flux of water and temperature between 18,8-22,5 ºC from November 2006 to May 2007, the fecundity index was lower than others in higher latitudes, around 100 larvae/female g, for individuals between 270 and 690 g. The incubation time torn out to be similar to colder conditions, but the period between hatching and the next spawning decreased even to 0 days. The annual spawning cycle, unlike the described for Northern Atlantic populations, could range the whole year, with 3, 4 or even more consecutive spawnings

Análisis espacio-temporal de las praderas de Cymodocea nodosa (Ucria) Ascherson en la isla de Gran Canaria

Máster Oficial en Gestión Costera

Caracterización de las fuentes mantélicas de los magmas plio-cuaternarios de Gran Canaria (Islas Canarias)

VIII Congreso geológico de España, Oviedo, 17-19 julio 2012

Effects of ocean acidification on the brown alga "Padina pavonica": decalcification due to acute and chronic events

[EN] Since the industrial revolution, anthropogenic CO2 emissions have caused ocean acidification, which particularly affects calcified organisms. Given the fan-like calcified fronds of the brown alga Padina pavonica, we evaluated the acute (shortterm) effects of a sudden pH drop due to a submarine volcanic eruption (October 2011–early March 2012) affecting offshore waters around El Hierro Island (Canary Islands, Spain). We further studied the chronic (long-term) effects of the continuous decrease in pH in the last decades around the Canarian waters. In both the observational and retrospective studies (using herbarium collections of P. pavonica thalli from the overall Canarian Archipelago), the percent of surface calcium carbonate coverage of P. pavonica thalli were contrasted with oceanographic data collected either in situ (volcanic eruption event) or from the ESTOC marine observatory data series (herbarium study). Results showed that this calcified alga is sensitive to acute and chronic environmental pH changes. In both cases, pH changes predicted surface thallus calcification, including a progressive decalcification over the last three decades. This result concurs with previous studies where calcareous organisms decalcify under more acidic conditions. Hence, Padina pavonica can be implemented as a bio-indicator of ocean acidification (at short and long time scales) for monitoring purposes over wide geographic ranges, as this macroalga is affected and thrives (unlike strict calcifiers) under more acidic conditions

Procedimiento para la evaluación de la cobertura vegetal en sistemas sedimentarios costeros mediante tecnologías de la información geográfica (TIG): La Graciosa (Islas Canarias)

Máster Oficial en Gestión Costera

Whake watching and characterization on the south coast of Gran Canaria

[EN]On the basis of an extensive work of bibliographic documentation, supplemented by a work of field research in the area of study (watching and direct participation in the activity), in the present work aims to provide the basic information for understanding the current situation of cetaceans on the south coast of Gran Canaria, Canary Islands, Spain, between July on 2013 and March on 2014 (the months of February and March of 2014 correspond to my work of field research in the area of study). There will be a guide to the species that integrate the sector of the large whales, analyzing their specific characteristics, its distribution, its degree of protection

Obtención en cautividad de puestas naturales del pez de limon(Seriola dumerili), en la isla de Gran Canaria (España).

[EN]In the present study, natural spawning of a broodstock group of greater amberjack (Seriola dumerili) is described with regards to: date, number of spawns, and total number of eggs produced per spawn. Fish werecaught in 2011 in the Canary Islands, Gran Canaria (Canary Islands, Spain), and kept in captivity. At the end of May 2014, the broodstock group was formed by two females with a weight 9.81±1.08 kg, size 90.0±2.82cm, with oovocites > 800μ, and five males 9.46±2.04 kg, 86.75±5.43 cm, all fluent with sperm. Between the 1stof June and 18thof October 2014, a total of 25.60 million eggs were obtained in 23 spawns.

Radon in Groundwater of the Northeastern Gran Canaria Aquifer

[EN]Rn has been detected in 28 groundwater samples from the northeast of Gran Canaria (Canary Islands, Spain) utilizing a closed loop system consisting of an AlphaGUARD monitor that measures radon activity concentration in the air by means of an ionization chamber, and an AquaKIT set that transfers dissolved radon in the water samples to the air within the circuit. Radon concentration in the water samples studied varies between 0.3 and 76.9 Bq/L. Spanish radiological protection regulations limit the concentration of 222Rn for drinking water to 100 Bq/L, therefore the values obtained for all the analyzed samples are below this threshold. The hydrogeological study reveals a significant correspondence between the radon activity concentration and the material characteristics of the aquifer.