Flipper Tagging

Nesting females are tagged using titanium flipper tags to enable the identification of individual females. Two tag series have been used in Tanzania with tag prefixes TA and TZ.  In 2011, 2012 and 2013 Sea Sense conducted a saturation tagging programme in Juani Island, Mafia District which is the most important green turtle nesting site in Tanzania.  The tagging was conducted during the peak nesting months of April and May and provided  data on clutch frequencies, levels of nest site fidelity and duration of inter-nesting intervals. An additional flipper tagging programme was started in 2013 in Temeke District which supports the second largest green turtle rookery in Tanzania. 

The tagging programmes will be repeated in future years to help identify re-migration intervals and determine the true status of nesting populations at the two sites.  More than two thirds of all recorded green turtle nests in Tanzania are laid in Juani Island and Temeke District so data from a continuous and focused monitoring programme can also be used to determine population sizes at other nesting sites in Tanzania where only track counts are available.

Satellite Tracking

Molly returns to the sea

In 2012 Sea Sense embarked on the first ever sea turtle satellite telemetry project in Tanzania to identify migratory pathways and the location of important foraging grounds. Seven satellite tags were deployed on nesting green turtles.

Five of the turtles migrated to foraging grounds within Tanzania. The remaining two turtles continued north along the East African coast. Mwisho settled on a foraging ground just north of Mombasa in Kenya while Zianna went further north to Somalia, an impressive 3,500km from her nesting beach in Mafia! These are the first migratory corridors ever identified for turtles nesting in Tanzania.

Four tags were generously funded by WWF.  The three remaining tags were funded by the South West Indian Ocean Fisheries Project (SWIOFP) which was an ambitious region wide project focusing on the development of sustainable fisheries. SWIOFP also funded the deployment of satellite tags in Kenya, Madagascar, Mozambique, Seychelles and Mauritius and tracking data from these regional partners identified Tanzania's Rufiji Delta as one of five regional 'hotspots' for green turtle foraging activity. 

The Secretariat of the Indian Ocean South East Asia Marine Turtle Memorandum of Understanding (IOSEA MoU) is currently developing a 'Network of Sites of Importance for Marine Turtles' in the western Indian Ocean region and has invited nominations from signatory states. Sea Sense worked closely with the Tanzania IOSEA Focal Person to prepare and submit a nomination for the Rufiji Delta and the SWIOFP satellite tracking data were used as important supporting evidence. 

In light of the success of the first satellite telemetry project in 2012, Sea Sense received funding for deployment of a further four satellite tags. One was deployed in Pangani in 2013 and so far one has been deployed in 2014 in Mnemba Island, Zanzibar.  We look forward to learning more about Tanzania's sea turtles and we will be sure to keep you updated!

Did you know?

Every whale shark has an individual pattern of spots, a bit like a human fingerprint!


Sea Sense and a reflection on 2014

2014 was an extremely busy year for Sea Sense and we achieved everything we set out to, plus a few...

Expected Green Turtle Hatching Dates in May 2016

Mafia Island
South Beach