Regresión de las algas marinas en las Islas Canarias y en la costa atlántica de la Península Ibérica por efecto del cambio climático

Versión del edito

Dancing in the Dark: The Relationship between Policy Research and Policy Making in Dutch Higher Education

The idea that research is directly useful in the policy process has been widely disputed,2 and much has been written about the differences between the contexts or “cultures” in which research is produced and in which policy is made.3 A number of authors, however, have pointed out indirect ways in which policy makers may make use of research findings or have tried to find more complex ways of understanding and describing the relationships between researchers and policy makers.4 It has been proposed, for example, that the categories of researcher and policy maker are not always mutually exclusive and that interactions between all actors involved in this process could be better described as two-way, rather than only as one-way, interactions.

Impact of wastewater treatment plant discharges on macroalgae and macrofauna assemblages of the intertidal rocky shore in the southeastern Bay of Biscay

International audienceRocky intertidal habitats are particularly vulnerable to anthropogenic pressures especially in areas with high urban concentrations such as southeastern Bay of Biscay. This research aims to establish an assessment of the potential impact of sewage discharges on intertidal rocky benthic assemblages on macroalgae and on macrofauna as required by the European Directives (Water Framework Directive -WFD and Marine Strategy Framework Directive -MSFD). The assemblages were sampled at five locations according to a control-impact design. A moderate detectable effect of discharges was highlighted on the assemblage structure by means of multivariate analyses but this was less evident using other biological and ecological metrics. Results would also suggest that benthic macroalgae constitute for the study area the best relevant biotic component to assess the effect of this pressure on the intertidal rocky platform habitats. Changes in the relative abundance of Ceramium spp., Corallina spp. and Halopteris scoparia were mainly responsible of the dissimilarities found. Finally, a pseudo-ecological quality ratio, based on the current WFD metrics, was also calculated for each site within locations (i.e. each distance from the outfall) to assess its sensitivity to this type of pressure. Results were conformed with those of the WFD monitoring because the un- or less-impacted sites were ranked as “Good” contrary to the others ranked as “Moderate”. Thus, this work provides additional information for the MSFD and bridges deficiencies emphasized by Directives on the response of biological indicators to various pressures and the biocenosis of southeastern Bay of Biscay

Adiciones corológicas a la flora bentónica marina del Cantábrico

Publicado

Recent changes in the distribution and abundance of marine seaweeds in the north of the Iberian Peninsula and its relation to climate change

The Cantabrian coast is an area of special biogeographical interest because the existence of a marked longitudinal gradient, mainly related to the sea surface temperature (SST) and the intensity and frequency of upwellings. Since the late 19th Century, there is scientific evidence on the existence of fluctuating expansion-retraction periods of certain seaweeds, mainly fucoids and laminarians, associated with cooling or warming events. However, since the beginning of the 21st Century, macroalgae have experienced dramatic changes to date unknown. Populations of brown and red algae typical of cold-temperate waters such as Himanthalia elongata, Fucus vesiculosus, F. serratus, Laminaria hyperborea, L. ochroleuca, Saccorhiza polyschides and Chondrus crispus have undergone significant declines in abundance and even disappeared in many localities. Subtidal stands of Gelidium corneum have undergone a decline in biomass and coverage in the warmest part of the thermal gradient (the Basque coast), while populations westward from Cape Peñas (Asturias) are in expansion. In contrast, SST warming may have enhanced the growth of non-native species and algae with warm water affinities such as calcareous algae, Stypocaulon scoparium, Cystoseira tamariscifolia and Bifurcaria bifurcata. In Galicia, westem area characterized by colder waters, the response of vegetation is more heterogeneous, varying between locations and habitats. Models of distributions based on future climate scenarios suggest massive declines of several canopy species along the Cantabrian coast. The disappearance or decline of these habitat-forming macrophytes may have severe consequences on the functioning of the ecosystem. Increases in SST, air temperature, irradiance, intensity and frequency of storm waves and transparency of coastal waters, in combination with a reduction of upwelling frequency and intensity could be factors involved in those changes detected in macroalgae distribution. In addition, in some cases, the resilience of sorne macroalgae, can be compromised by human pressures (i.e. waste discharges, exploitation), accelerating their decline

Distributional shifts of canopy-forming seaweeds from the Atlantic coast of Southern Europe

Versión del editor2,23