Evidence that St. Helena island is an important multi-use habitat for whale sharks
Published on 21. March 2016
Evidence that St. Helena island is an important multi-use habitat for
whale sharks, Rhincodon typus, with the first description of putative mating in this species
Elizabeth Clingham, Judith Brown, Leeann Henry, Annalea Beard, Alistair D Dove
Preliminary observations of whale shark behavioural ecology are presented from St. Helena, a remote volcanic island in the South Atlantic. Whale shark sightings by fishers, government biologists and the general public have been recorded by the St. Helena Government since February 1999 and are presented here through to the end of 2014. A total of 328 sightings was collected on an ad hoc basis, a total of 931 animals, although the number of re-sightings within that total is not known. Increases in observations are likely coincident with increases in surveillance and public awareness of the presence of this species in the waters surrounding St Helena. On two occasions, small aggregations of whale sharks were observed at the bay at Jamestown; the animals were engaged in surface feeding behaviour similar to that seen in coastal aggregations in Mexico and Qatar. In contrast to other aggregations, however, animals observed at St Helena were numerically dominated by adult females, although mature males and some juveniles have also been observed. On two occasions, eyewitness accounts of mating behaviour were reported by two different reliable observers. These events took place in 2005 and 2007, both approximately 16 kilometers from shore, at different sites. They both involved belly-to-belly contact behaviour at the surface, in one case involving at least two males. This is the first report of putative mating behaviour in the whale shark. With the presence of both adult and juvenile animals, surface feeding aggregations, apparently pregnant females and the first observations of putative mating, the waters around St Helena are clearly an important multi-use habitat for whale sharks and are worthy of concerted conservation efforts.
PeerJ Preprints 4:e1885v1