Abundance and site fidelity of bottlenose dolphins off a remote oceanic island (Reunion Island, southwest Indian Ocean)

Abstract Two bull sharks ( Carcharhinus leucas ) were tagged in coastal waters off Reunion Island in the tropical Indian Ocean and where tracked for 174 and 139 days using both popup satellite archival tags (pSAT) and acoustic tags. Both sharks spent a majority of their time inshore (58.1% and 89.9% in the male and the female respectively). The female performed short excursions. The male alternated residence time along the coast with wide ranging movements and performed one extensive open-ocean excursion near a seamount situated at more than 200 km from the island. The differences in the residency and home range of both sharks probably reflect different patterns of foraging and mating behaviors in the male and the female. These results underline the importance of developing risk-mitigation management taking into account the movements of sharks, and of double tagging in telemetry studies that attempt to measure the degree of fidelity of a species.

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A Major Rainfall Event: The 27 February–5 March 1993 Rains on the Southeastern Slope of Piton de la Fournaise Massif (Reunion Island, Southwest Indian Ocean)

Monthly Weather Review ◽

10.1175/1520-0493(1997)125<3341:amretf>2.0.co;2 ◽

1997 ◽

Vol 125 (12) ◽

pp. 3341-3346 ◽

Cited By ~ 13

Author(s):

Alain Barcelo ◽

René Robert ◽

Jean Coudray

Keyword(s):

Indian Ocean ◽

Rainfall Event ◽

Reunion Island ◽

Southwest Indian Ocean ◽

Piton De La Fournaise ◽

Réunion Island

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Bathymetric Distribution of Soft Bottom Tropical Macrobenthos From the Exposed East Coast of Reunion Island (Southwest Indian Ocean)

Western Indian Ocean Journal of Marine Science ◽

10.4314/wiojms.v5i1.28493 ◽

2007 ◽

Vol 5 (1) ◽

Author(s):

L Bigot ◽

J P Quod ◽

C Conand

Keyword(s):

Indian Ocean ◽

East Coast ◽

Reunion Island ◽

Soft Bottom ◽

Bathymetric Distribution ◽

Southwest Indian Ocean ◽

Réunion Island

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Impact of convection on the upper-tropospheric composition (water vapor and ozone) over a subtropical site (Réunion island; 21.1° S, 55.5° E) in the Indian Ocean

Atmospheric Chemistry and Physics ◽

10.5194/acp-20-8611-2020 ◽

2020 ◽

Vol 20 (14) ◽

pp. 8611-8626 ◽

Cited By ~ 1

Author(s):

Damien Héron ◽

Stéphanie Evan ◽

Jérôme Brioude ◽

Karen Rosenlof ◽

Françoise Posny ◽

...

Keyword(s):

Indian Ocean ◽

Local Maximum ◽

Reunion Island ◽

Mixing Ratio ◽

Southwest Indian Ocean ◽

Air Masses ◽

Upper Troposphere ◽

Mixing Ratios ◽

Réunion Island ◽

The Impact

Abstract. Observations of ozonesonde measurements of the NDACC/SHADOZ (Network for the Detection of Atmospheric Composition Change and the Southern Hemisphere ADditional OZonesondes) program and humidity profiles from the daily Météo-France radiosondes at Réunion island (21.1∘ S, 55.5∘ E) from November 2013 to April 2016 were analyzed to identify the origin of wet upper-tropospheric air masses with low ozone mixing ratio observed above the island, located in the southwest Indian Ocean (SWIO). A seasonal variability in hydration events in the upper troposphere was found and linked to the convective activity within the SWIO basin. In the upper troposphere, ozone mixing ratios were lower (mean of 57 ppbv) in humid air masses (RH > 50 %) compared to the background mean ozone mixing ratio (73.8 ppbv). A convective signature was identified in the ozone profile dataset by studying the probability of occurrence of different ozone thresholds. It was found that ozone mixing ratios lower than 45 to 50 ppbv had a local maximum of occurrence between 10 and 13 km in altitude, indicative of the mean level of convective outflow. Combining FLEXPART Lagrangian back trajectories with METEOSAT-7 infrared brightness temperature products, we established the origin of convective influence on the upper troposphere above Réunion island. It has been found that the upper troposphere above Réunion island is impacted by convective outflows in austral summer. Most of the time, deep convection is not observed in the direct vicinity of the island, but it is observed more than 1000 km away from the island, in the tropics, either from tropical storms or the Intertropical Convection Zone (ITCZ). In November and December, the air masses above Réunion island originate, on average, from central Africa and the Mozambique Channel. During January and February the source region is the northeast of Mozambique and Madagascar. Those results improve our understanding of the impact of the ITCZ and tropical cyclones on the hydration of the upper troposphere in the subtropics in the SWIO.

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