The MEGASCOPE methodology is based on 2 active observers on the deck, recording a certain number of parameters in the sampling area covered by the vessel.
Firstly, they note the observation conditions, i.e. whether or not they are beneficial for the detection of cetaceans.
Then, they will note all the observations made, which requires identifying and counting the megafauna present (cetaceans, seabirds, turtles, large pelagic fish…) and also any object encountered (waste, ship…).
Illustration: Mapping of cetacean sightings in the Bay of Biscay during the PELGAS 2016 campaign.
These studies target key links in the oceanic food chain where top predators are located. The results obtained make it possible to compare the distribution of cetaceans with that of pelagic fish in order to learn more about the relationships between these predators and their potential prey.
These missions are of major importance for understanding this marine environment. They constitute the first series of data on the distribution and composition of the population of marine top predators for spring in the Bay of Biscay. In addition to this, other campaigns of this type have been carried out, such as EVHOE in the autumn or IBTS or CGFS in the Channel.
Today, these results are the source of long term monitoring which allow us to have clear answers to characterise preferential habitats, notably for some indicator species such as the common dolphin or the Northern Gannet.