Observatoire Pelagis aerial surveys 2002-2021

Original provider:
Observatoire PELAGIS UAR 3462 University La Rochelle - CNRS

Dataset credits:
Observatoire PELAGIS UMS 3462, University La Rochelle - CNRS -Agence des Aires Marines Protégées - Direction de l'Eau et de la Biodiversité

Abstract:
In order to establish a baseline map of cetaceans and other pelagic megafauna across the French EEZ, the French agency for marine protected areas (AAMP) decided to conduct a series of surveys allowing hotspots of abundance and diversity to be identified and a future monitoring scheme to be established. A dedicated aerial survey methodology, following standard protocols, was preferred to ship surveys. The general design corresponds to published protocols prepared for small cetaceans, but data for other marine mammals (large whales, sirenians), seabirds, sea-turtles, large teleosts and large elasmobranchs) are collected as well. Data collected include species, group size, angle to survey track for cetaceans located within 500m on both sides of survey track, allowing line transect data analyses. For seabirds all encounters located within 200m on both sides of survey track are recorded for strip-transect analysis. Covariates collected on board include sea-state, turbidity, glare and cloud coverage. The study areas include all sectors of the French EEZ: North-East Atlantic, the tropical Atlantic (French Caribbean and Guiana), Indian (Reunion Island, Mayotte and the Scattered Islands) and south Pacific oceans (French Polynesia, New Caledonia, Wallis and Futuna).
These surveys follow the general SCANS methodology (Hiby and Lovell, 1998) adapted to aircrafts. A zigzag track layout is used and transects are sampled at a target altitude of 180 m and ground speed of 90 nm.h-1 (167 km.h-1). Survey platforms are high-wing, double-engine aircrafts fitted with bubble windows; a Partenavia P68 was used in 2008 in the Atlantic and two Britten Norman BN-2 in 2009-10 in the southwest Indian Ocean.
Survey crew typically consists in two trained observers observing with naked eyes and a flight leader in charge of data collection.