Calidad de las aguas costeras del municipio de Denia

La calidad de las aguas costeras en muchas regiones del mundo se ha deteriorado en los últimos años a medida que la población humana y las actividades se han incrementado en las regiones costeras, y en especial en la costa mediterránea. La presión humana es responsable de importantes cambios en los ecosistemas costeros, particularmente es una área con carga excesiva de nutrientes. Concentraciones elevadas de nutrientes pueden producir eutrofización, y en consecuencia, floraciones de algas nocivas y deterioro de la calidad del agua. En este estudio se llevaron a cabo tres campañas, en las cuales se tomaron muestras en once transectos diferentes a lo largo de la costa de Dénia, a distintas distancias de la costa y diferentes profundidades para observar las variaciones temporales y espaciales de la calidad de las aguas. A partir de estas muestras se analizaron los diferentes nutrientes relevantes (nitrógeno inorgánico disponible, fosfatos y sílice) y clorofila a, para observar la relación entre estos parámetros. Se observó que los puntos en los que existía una fuente de agua dulce la cantidad de nutrientes, era mayor. En cambio los resultados de clorofila a dependían de la cantidad de nutriente y de cuál era el nutriente limitante.The quality of coastal waters in many regions of the world has deteriorated in recent years as the human population and activities have increased in the coastal regions, especially on the Mediterranean coast. Human pressure is responsible for significant changes in coastal ecosystems, in particular is an area with excessive nutrient loading. High concentrations of nutrients can cause eutrophication and therefore, blooms and deterioration of water quality. In this study they conducted three campaigns, in which samples were taken in eleven different transects along the coast of Dénia, at different distances from the coast and different depths to observe the temporal and spatial variations in the quality of water. From these samples the various relevant nutrients (available inorganic nitrogen, phosphate and silica) and chlorophyll a, to observe the relationship between these parameters were analyzed. It was observed that the points at which there was a source of fresh water the amount of nutrients, was greater. Instead chlorophyll results depended on the amount of nutrient and what the limiting nutrient.Alventosa Ferri, J. (2015). Calidad de las aguas costeras del municipio de Denia. Universitat Politècnica de València. http://hdl.handle.net/10251/55161TFG

Micro-scale distribution of recently-detached Carybdea marsupialis box jellyfish along the coast of Denia (W. Mediterranean)

5th International Jellyfish Bloom Symposium, 30 May to 3 June 2016, Barcelona.-- 1 pageCarybdea marsupialis have been found in high densities (~90 ind m3 juveniles, ~51 ind m3 adults) in shallow waters along the coast of Denia (W. Mediterranean) since summer 2008, varying significantly in abundance from year to year. In order study the role of juvenile stages in population dynamics, we analyzed the seasonal and micro-scale spatial distribution of recently-detached cubomedusae (~0.5 mm DBW). The main objective was to determine whether their distribution was focused or dispersed, as a means of revealing the location of the polyps. We also tested the correlation between environmental variables such as nutrient (P, N, Si), Chl-a and zooplankton abundance. During 2015 we collected samples from 33 points: 11 points along 15km of coastline at 3 distances from the coast (0m, 250m and 500m). Recently-detached C. marsupialis were almost only present at a depth of 0m in the samples collected from May to July. Maximum densities (~5 ind m3) were recorded in June in the centre of the study area. We hypothesized that the polyps would be located where the adults had mated the previous year. However, the distribution of recently-detached individuals did not coincide with the higher 2014 adult densities. This might be ascribed to the advection caused by the currents, which alternate along the coast. Abundance was not directly correlated with either zooplankton, nutrients or Chl-a. The next step would be to model the currents pattern and its effect in the dispersion and survival of juvenilesPeer Reviewe