The return of the Shark Team

Demian and his shark team came back in October to pick up and continue their work tagging the Sharks of Glovers Reef (see May entry).

Demian and Debbie on their way to pick up receivers

This time Demian was accompanied by his lovely assistant/better half, who showed us a trick or two in staying cool in the face of these toothy animals.

Norlan Lamb is picking up a receiver which records each time a shark with an transmitor swims by.

Beside his usual activities of tagging Glovers reef sharks to get an estimate of the population and to monitor it, Demian tested a deep long line to see what lurked beneath 100(+)m waters of Glovers. To everyone's surprise and delight he recorded a species that had not yet been observed: the Cuban Night Shark or Carcharhinus signatus.

Carcharinus signatus coming up from the depths.

Commonly caught in Cuba, these sharks travel in schools, prefering waters between 50 to 100m deep with some occuring down to at least 600m. It makes vertical migration to the surface at night. (see http://www.fao.org/figis/servlet/species?fid=2815)

This night shark measured about 2m. Demian is flipping it on its back to remove the hook and release it.

TheNight Shark is classed as a species of concern. Historically night sharks were the main catch of cuban artisanal fisheries in 1937-1941. However the population seems to have declined with the development of longline pelagic fishing industries. These sharks are often caught as bycatch on longlines targetting tunas. (see http://www.nmfs.noaa.gov/pr/pdfs/species/night_shark.pdf)

Releasing the shark is always a strategic moment as you don't want to hurt it or it to hurt you!

Until next time, please stay off shark fin soup....