scholarly journals Shift in demographic structure and increased reproductive activity of loggerhead turtles in the French Mediterranean Sea revealed by long-term monitoring

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Fanny Girard ◽  
Sidonie Catteau ◽  
Delphine Gambaiani ◽  
Olivia Gérigny ◽  
Jean Baptiste Sénégas ◽  
...  
Keyword(s):  
Environmental Changes ◽  
Size Structure ◽  
Reproductive Activity ◽  
Western Mediterranean ◽  
Surface Warming ◽  
The North ◽  
Western Mediterranean Basin ◽  
Loggerhead Turtles ◽  
Nesting Sites ◽  
Nesting Activity

AbstractClimate-induced environmental changes are profoundly impacting marine ecosystems and altering species distribution worldwide. Migratory organisms, including sea turtles, are expected to be particularly sensitive to these variations. Here, we studied changes in the size structure and reproductive activity of loggerhead turtles in the French Mediterranean over 30 years. Overall, there was a significant increase in the size of observed loggerheads between 1990 and 2020. However, this increase was only significant during the breeding/nesting season (May to September) and was driven by the increased presence of adults. Furthermore, nesting activity along the French coast was detected in 2002 for the first time in more than 50 years, and has become frequent after 2014, with nests discovered every year. The number of eggs laid as well as incubation duration and success varied among sites but fell within the range reported at established Mediterranean nesting sites. These observations, along with recent reports of breeding activity and evidence of significant sea surface warming, suggest that the north-western Mediterranean basin has become increasingly suitable to loggerhead turtles. We postulate that this range expansion is the result of climate change and propose that emerging nesting activity in France should be closely monitored and guarded against human activities.

scholarly journals Potential deployment of offshore bottom pressure gauges and adoption of data assimilation for tsunami warning system in the western Mediterranean Sea

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Mohammad Heidarzadeh ◽  
Yuchen Wang ◽  
Kenji Satake ◽  
Iyan E. Mulia
Keyword(s):  
Data Assimilation ◽  
Warning System ◽  
Western Mediterranean ◽  
Tsunami Warning ◽  
Sensitivity Analyses ◽  
Bottom Pressure ◽  
Tsunami Warning System ◽  
Earthquake Scenarios ◽  
The North ◽  
Western Mediterranean Basin

AbstractWestern Mediterranean Basin (WMB) is among tsunamigenic zones with numerous historical records of tsunami damage and deaths. Most recently, a moderate tsunami on 21 May 2003 offshore Algeria, North Africa, was a fresh call for strengthening tsunami warning capabilities in this enclosed water basin. Here, we propose to deploy offshore bottom pressure gauges (OBPGs) and to adopt the framework of a tsunami data assimilation (TDA) approach for providing timely tsunami forecasts. We demonstrate the potential enhancement of the tsunami warning system through the case study of the 2003 Algeria tsunami. Four scenarios of OBPG arrangements involving 10, 5, 3 and 2 gauges are considered. The offshore gauges are located at distances of 120–300 km from the North African coast. The warning lead times are 20, 30, 48 and 55 min for four points of interest considered in this study: Ibiza, Palma, Sant Antoni and Barcelona, respectively. The forecast accuracies are in the range of 69–85% for the four OBPG scenarios revealing acceptable accuracies for tsunami warnings. We conclude that installation of OBPGs in the WMB can be helpful for providing successful and timely tsunami forecasts. We note that the OBPG scenarios proposed in this study are applicable only for the case of the 2003 Algeria tsunami. Further studies including sensitivity analyses (e.g., number of OBPG stations; earthquake magnitude, strike, epicenter) are required in order to determine OBPG arrangements that could be useful for various earthquake scenarios in the WMB.

scholarly journals Understanding Precipitation Changes in Iberia in Early Spring: Weather Typing and Storm-Tracking Approaches

2006 ◽  
Vol 7 (1) ◽  
pp. 101-113 ◽  
Author(s):  
Daniel Paredes ◽  
Ricardo M. Trigo ◽  
Ricardo Garcia-Herrera ◽  
Isabel Franco Trigo
Keyword(s):  
Iberian Peninsula ◽  
North Atlantic ◽  
Large Scale ◽  
Western Mediterranean ◽  
Early Spring ◽  
The North ◽  
Western Mediterranean Basin ◽  
The North Atlantic ◽  
Circulation Changes ◽  
Precipitation Trends

Abstract March monthly accumulated precipitation in the central and western regions of the Iberian Peninsula presents a clear continuous decline of 50% during the 1960–97 period. A finer analysis using daily data reveals that this trend is exactly confined to the month of March. However, this is merely the most visible aspect of a larger phenomenon over the North Atlantic/European sector. The European precipitation trends in March for the period 1960–2000 show a clear distribution of increasing precipitation in the northern regions (the British Isles and parts of Scandinavia) together with decreasing trends throughout the western Mediterranean Basin. Relevant circulation changes over the North Atlantic and European sectors explain these precipitation trends. First, a regional Eulerian approach by means of a weather-type (WT) classification shows that the major rainfall contributors in March display significantly decreasing frequencies for the Iberian Peninsula, in contrast to the corresponding “wet” weather types for the U.K./Ireland sector, which display increasing frequencies. Within a larger context, a Lagrangian approach, based on the analysis of storm tracks over Europe and the North Atlantic region, reveals dramatic changes in the location of cyclones in the last four decades that coincide with the corresponding precipitation trends in Europe. The North Atlantic Oscillation is suggested to be the most important large-scale factor controlling both the circulation changes and the precipitation trends over the Euro–Atlantic area in March. Finally, the potential impact of reduced precipitation for rivers and water resources in the Iberian Peninsula is considered.

Changes in Carbon Isotope Discrimination in Grain Cereals From the North-Western Mediterranean Basin During the Past Seven Millenia

1993 ◽  
Vol 20 (1) ◽  
pp. 117 ◽  
Author(s):  
JL Araus ◽  
R Buxo
Keyword(s):  
Middle Ages ◽  
Mediterranean Basin ◽  
Carbon Isotope Discrimination ◽  
Western Mediterranean ◽  
Isotope Discrimination ◽  
The North ◽  
Western Mediterranean Basin ◽  
Use Efficiency ◽  
North Western ◽  
The Middle Ages

Carbon isotope discrimination (Δ) was determined for kernels of six-row barley and durum wheat cultivated in the north-western Mediterranean basin during the last seven millennia. Samples from the Neolithic, Bronze, Iron and Middle Ages came from different archaeological sites in Catalonia. Samples for the period 1910-20 and 1990 were also analysed. There was a slight decrease (P=0.10, carbonisation-corrected values) in Δ from the Neolithic to the Iron Age period and a much steeper decrease from the Middle Ages to 1910-20 (P<0.01). Since water-use efficiency and isotope discrimination are negatively correlated, from the pattern of change in Δ it is suggested that there has been a progressive increase in the water-use efficiency (WUE) of these cereals. Since the Middle Ages this has coincided with increases in atmospheric CO2 concentration. Thus, for a given relative humidity and air temperature, the estimated WUE (measured as the ratio of CO2 assimilation to transpiration) from the Neolithic to the Middle Ages samples ranged between 65-70% of present time WUE values, whereas WUE for 1910-20 was about 86% of present values.

Tectonics and deep structure of the north-western Mediterranean Basin

1995 ◽  
Vol 12 (6) ◽  
pp. 645-666 ◽  
Author(s):  
Alain Mauffret ◽  
Georges Pascal ◽  
Agnès Maillard ◽  
Christian Gorini
Keyword(s):  
Mediterranean Basin ◽  
Deep Structure ◽  
Western Mediterranean ◽  
The North ◽  
Western Mediterranean Basin ◽  
North Western
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