Aerial survey in the straits
The SPEE project (Suivi de la mégafaune marine au large des PErtuis charentais, de l’Estuaire de la Gironde et de Rochebonne par observation aérienne) commissioned by the Parc naturel marin de l’estuaire de la Gironde et de la mer des Pertuis, aims to improve knowledge of the distribution, abundance and use of the area by the marine megafauna in the Park and the “Pertuis Charentais-Rochebonne” SPA.
Objectives
This data acquisition survey via aerial sighting is aimed at marine birds, marine mammals and marine turtles, rays, sharks and large visible fish, floating macro waste on the surface as well as nautical traffic. The aim is to identify them, specify their numbers and distribution in the study area, and characterise seasonal variations. It should also enable the relationships between the environment and the presence of the species monitored to be highlighted. The expected results, especially for birds and marine mammals, are data on species richness, distribution and abundance, seasonal variability of these parameters and preferential habitats in relation to the environmental parameters of the area.
Sampling
For the sake of ecological consistency in the monitoring of these mobile species, the study area extends beyond the administrative boundaries of the Park and the SPA and covers approximately 15,000 km². This represents 4 overflight sessions of 3,500 km each per year, divided into 4 successive sampling plans over the years 2019 and 2020.
Some figures
3,500 km of transects were flown per season over an area of 15,000 km².
216 hours of flights and 13,600 km of effort spread over 4 seasons and the two years 2019 and 2020.
25,000 sightings collected:
– 700 sightings of marine mammals, including three regular species present all year round but with higher densities in winter for the common dolphin and harbour porpoise.
– More than 15,000 sightings of birds, with many species wintering offshore and high densities in winter and autumn, except in the interior of the straits where the presence of certain species of seabirds is more marked in summer.
– a thousand sightings of large pelagic fish or sharks.
– nearly 4,000 detections of floating waste.
In the future..
Analyses are ongoing, and this overflight survey will continue in 2021 as four new sessions per season will be carried out to complete the knowledge and allow a more global analysis.
Report 2019 (in french)Report 2020 (in french)Report 2021 (in french)
