SMSG Blog

Expedition blogs and news from the Shallow Marine Surveys Group

Hawksbill tagging underway (well, nearly)…

[caption id="attachment_392" align="alignleft" width="300"] Sam Weber instructing volunteer turtle catchers on the finer points of the art.
Image: W Dimmlich

Attempts to capture and tag some of Ascension Island’s elusive hawksbill turtles (Eretmochelys imbricata) got underway during two night dives at the Pierhead in Georgetown this week. Best known for its globally important nesting population of green turtles (Chelonia mydas), Ascension Island also has a small resident population of critically endangered hawksbill turtles about which very little is known. Hawksbills do not nest on Ascension and from their sizes it appears that most individuals are sexually immature juveniles or sub-adults, but the nesting population(s) from which they originate and the migratory pathways which bring them to the Island remain a mystery. By fitting metal flipper tags carrying a return address and taking tissue samples for mitochondrial DNA analysis we hope to answer some of these questions, as well as adding to scarce data on growth rates and residence times at Ascension. But first we have to catch them!




[caption id="attachment_393" align="alignleft" width="584"] A young hawksbill is spotted in the shallows near the pier.
Image: P v West


[caption id="attachment_394" align="alignleft" width="584"] As it swims close to the shore Dion Poncet prepares to leap.
Image: P v West


[caption id="attachment_396" align="alignleft" width="584"] Unfortunately a near miss and the turtle can be seen just escaping Dion's outstretched hand.
Image: P v West


Every evening, as many as 5-6 hawksbill turtles gather around Georgetown Pier where artificial lighting and fish discards allow them to continue foraging late into the night, making this the perfect place to start our tagging campaign. After an unsuccessful attempt earlier in the week, a crack team of elite military divers including Simon Browning, Simon Plummer and Phil Thomas managed to capture one of the largest hawksbills yet seen on Ascension - too large unfortunately, as it proved too heavy to land in the conditions at the Pierhead! Nevertheless, spurred on by their progress so far the team are planning a return visit this week and we will post an update soon.

[caption id="attachment_397" align="aligncenter" width="584"] Success! It takes Phil and two Simons to finally capture a hawksbill and shepherd it back to the pier.
Image: P v West


Contributed by Sam & Nicola Weber
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