Dynamique temporelle des paramètres physico-chimiques des lacs du littoral Aquitain

Les lacs et plans d’eau du littoral Aquitain ont fait l’objet, et font encore l’objet par IRSTEA, de nombreux autres suivis de leurs paramètres physico-chimiques. Ces données, chacune récoltées pour des finalités précises, sont cependant dispersées dans de nombreux documents. Le but de ce stage est donc de rassembler l’ensemble des données physico-chimiques historiques disponibles à IRSTEA dans le but de bancariser ces données et d’analyser les dynamiques des principaux paramètres

Calcifying pteropod time series provides a baseline against which to measure local environmental change

International audienc

Pteropod time series from the North Western Mediterranean (1967 - 2003): impacts of pH and climate variability

International audienceEnvironmental changes resulting from anthropogenic CO2 emissions occur at global and local levels and have potentially harmful effects, particularly for calcifying taxa in the marine environment. A time series of pteropod abundance covering the period 1967-2003 was isolated from the Point B (northwestern Ligurian Sea) zooplankton time series. Inter-and intra-annual changes in the abundance of 3 families (Limacinidae, Cavoliniidae and Creseidae) were compared with the copepod time series to identify any differential effects driven by ocean acidification and temperature. pH values were hind-cast from total alkalinity estimated from local temperature and salinity measurements, and atmospheric CO2 taken from the Mauna Loa time series. Although surface waters were supersaturated with respect to aragonite throughout the study period, it is estimated that pH declined by 0.05 units. All pteropod groups displayed a trend of increasing abundance, suggesting that any deleterious effect of declining pH(T) in the range of 0.05 units has not caused sufficient reductions in fitness as to decrease local abundances between 1967-2003. Pteropod populations are influenced by inter-annual changes in summer temperatures. Spectral analysis identified a similar to 14 yr periodic oscillation in sea surface temperature. Similarly timed oscillations in abundance are present for all pteropod families but not for copepods, indicating a possible influence of the North Atlantic quasi-decadal mode on pteropod populations. While laboratory studies have shown pteropods to be sensitive to changes in pH, this analysis suggests that local and regional scale drivers have had a greater effect on pteropod populations in the northwestern Mediterranean Sea in recent decades. It should be noted that pH changes in laboratory studies exceed 0.05 pH units and that the saturation state with respect to aragonite (Oar) is usually much lower than that of the Mediterranean

InvaCost, a public database of the economic costs of biological invasions worldwide

International audienc

InvaCost, a public database of the economic costs of biological invasions worldwide [Data paper]

Biological invasions are responsible for tremendous impacts globally, including huge economic losses and management expenditures. Efficiently mitigating this major driver of global change requires the improvement of public awareness and policy regarding its substantial impacts on our socio-ecosystems. One option to contribute to this overall objective is to inform people on the economic costs linked to these impacts; however, until now, a reliable synthesis of invasion costs has never been produced at a global scale. Here, we introduce InvaCost as the most up-to-date, comprehensive, harmonised and robust compilation and description of economic cost estimates associated with biological invasions worldwide. We have developed a systematic, standardised methodology to collect information from peer-reviewed articles and grey literature, while ensuring data validity and method repeatability for further transparent inputs. Our manuscript presents the methodology and tools used to build and populate this living and publicly available database. InvaCost provides an essential basis (2419 cost estimates currently compiled) for worldwide research, management efforts and, ultimately, for data-driven and evidence-based policymaking. Sample Characteristic - Environmen