The main objective of this work is to examine statistical causality relationships between low-frequency modes of climate variability and winter (December to February) anomaly of net heat flux at the Mediterranean ai...The main objective of this work is to examine statistical causality relationships between low-frequency modes of climate variability and winter (December to February) anomaly of net heat flux at the Mediterranean air-sea interface. The introduction of the concept of Granger causality allowed us to examine the influence of these climates indices on the net heat flux anomaly and to select Mediterranean surface regions that really influenced by each index. Results show that the winter anomaly of the net heat flux in the Algerian basin south and the gulf of Lion is mainly caused by the Arctic Oscillation. El Nifio-Southern Oscillation influences much more the Algerian basin north and the northern lonian Sea. The Quasi-Biennial Oscillation affects only the Alboran and the Tyrrhenian Seas. But the Adriatic and Levantine basin are impacted by any climate index. They also show that these climate indices can increase explained variance in winter variations of air-sea net heat flux by 10% to 15%, with a lag of three seasons. These relationships are less persistent and spatially limited.展开更多
The pufferfish Lagocephalus sceleratus is an invasive Lessepsian species of Indo-Pacific origin that has established an increasing population over the past decade in the Levantine basin of the Mediterranean. Besides i...The pufferfish Lagocephalus sceleratus is an invasive Lessepsian species of Indo-Pacific origin that has established an increasing population over the past decade in the Levantine basin of the Mediterranean. Besides its toxicity due to the accumulation of tetrodotoxin in its body, it is causing damage to fishing gears and fishermen's catches. This study aims to provide data on the population structure and sexual maturity of this species in the eastern basin of the Mediterranean. A total of 214 individuals were collected in the coastal marine waters of Lebanon and Syria, between January 2012 and June 2013 by means of different types of nets and lines, on soft bottoms, at depths ranging from 10 m to 170 m. The TL (total length) of the samples varies between 10.8 cm and 71 cm. The most common size classes, represented by 125 individuals, are the ones between 30 cm and 50 cm TL, with a bulge at 40 cm, represented by 44 individuals. The average TL is 43.99 cm (standard deviation: SD = 17.65) for both males and females. The TW (total weight) of the specimens ranges between 14 g and 4,603 g with an average value of 1,458.52 g (SD = 1,329.49). The sex ratio (M/F) is 1:1.35 with a total number of 87 males, 118 females and nine unidentified individuals. The weight-length relationship (TW = aTLb) shows a negative allometric growth with b = 2.9481 and R2 = 0.9806. The condition factor (K) is close to one for all samples. The average value of the GSI (gonadosomatic index) shows a substantial increase from winter to spring. The spawning takes place between April and June.展开更多
文摘The main objective of this work is to examine statistical causality relationships between low-frequency modes of climate variability and winter (December to February) anomaly of net heat flux at the Mediterranean air-sea interface. The introduction of the concept of Granger causality allowed us to examine the influence of these climates indices on the net heat flux anomaly and to select Mediterranean surface regions that really influenced by each index. Results show that the winter anomaly of the net heat flux in the Algerian basin south and the gulf of Lion is mainly caused by the Arctic Oscillation. El Nifio-Southern Oscillation influences much more the Algerian basin north and the northern lonian Sea. The Quasi-Biennial Oscillation affects only the Alboran and the Tyrrhenian Seas. But the Adriatic and Levantine basin are impacted by any climate index. They also show that these climate indices can increase explained variance in winter variations of air-sea net heat flux by 10% to 15%, with a lag of three seasons. These relationships are less persistent and spatially limited.
文摘The pufferfish Lagocephalus sceleratus is an invasive Lessepsian species of Indo-Pacific origin that has established an increasing population over the past decade in the Levantine basin of the Mediterranean. Besides its toxicity due to the accumulation of tetrodotoxin in its body, it is causing damage to fishing gears and fishermen's catches. This study aims to provide data on the population structure and sexual maturity of this species in the eastern basin of the Mediterranean. A total of 214 individuals were collected in the coastal marine waters of Lebanon and Syria, between January 2012 and June 2013 by means of different types of nets and lines, on soft bottoms, at depths ranging from 10 m to 170 m. The TL (total length) of the samples varies between 10.8 cm and 71 cm. The most common size classes, represented by 125 individuals, are the ones between 30 cm and 50 cm TL, with a bulge at 40 cm, represented by 44 individuals. The average TL is 43.99 cm (standard deviation: SD = 17.65) for both males and females. The TW (total weight) of the specimens ranges between 14 g and 4,603 g with an average value of 1,458.52 g (SD = 1,329.49). The sex ratio (M/F) is 1:1.35 with a total number of 87 males, 118 females and nine unidentified individuals. The weight-length relationship (TW = aTLb) shows a negative allometric growth with b = 2.9481 and R2 = 0.9806. The condition factor (K) is close to one for all samples. The average value of the GSI (gonadosomatic index) shows a substantial increase from winter to spring. The spawning takes place between April and June.