Spatio-temporal distribution of Manta birostris in French Guiana waters

Manta ray (Manta birostris) is the largest ray species, but
little information is available regarding its biology, distribution and
migratory pattern. During an aerial survey conducted in French Guiana waters
(South America) in 2006, the observation of several dozen individuals all
swimming in the same direction prompted us to develop a research programme
on this species as part of an environmental impact assessment for oil
drilling. Overall, 117 aerial surveys were performed over 3 years in order
to complete a database for this species. In 54 of these flights, a total of
138 individuals were observed. A phenological analysis of this species in
French Guiana waters shows a peak presence between July and December, which
correlates with sea surface temperature and net primary production in the
ocean. The primary production in French Guiana waters is particularly active
during this period and could explain the annual pattern for this
filter-feeding animal.