Bob, the Two Oceans Aquarium’s rehabilitated green turtle, has officially entered the deep blue. After his release in late January 2023, the speedy ocean explorer has covered 2500 kilometres in 48 days of travelling along the continental shelf.
For the first time since his grand release, Bob is entering very deep waters. Thanks to a tracking update by the Turtle Conservation Centre and a detailed analysis by Talitha Noble, we know exactly what Bob has been up to in the first 48 days of his ocean adventure.
Also read: The latest tracking update marks Bob’s 41st day at sea
Update number 8, provided by Talitha Noble:
“Over the past 48 days, our team has watched in amazement as Bob meticulously stuck to the edge of the Agulhas Bank. The Agulhas Bank is the spectacular, shallow part of the southern African continental shelf where the Atlantic, Indian, and Southern Oceans converge. The waters here are very turbulent, but with the constant upwelling of seawater, they are also very nutrient-rich and attract lots of fish.”
When the Turtle Conservation Centre last checked in with Bob, he was nearing the edge of the continental shelf, close to Hermanus, where the turtle team was based on their road trip.
According to Noble, it’s encouraging to see Bob swimming smartly by staying on the gentle, warm surface of these nutrient-rich waters, where he can stock up on food and conserve energy.
Noble continues, “However, it seems as though Bob is ready for a deeper adventure! Over the past two days, Bob has transitioned from a water depth of 600 metres to over 3000 metres!”
The team wondered if he would continue around the Cape of Good Hope, but he decided to head in a more westerly direction and explore even further offshore.
“He is now 140km from shore. These deeper waters represent a big, brave step for our Bob, and we are excited to see him explore the deep blue!”
“Something to keep in mind as we track Bob is that satellite tags have a limited lifespan. While we hope that Bob’s will last up to two years, there is a real chance that the tag might fall off before then,” said Noble.
For this reason, the Turtle Conservation Centre also fitted Bob with an acoustic tag, which has a battery life that can last up to 10 years.
The South African Institute for Aquatic Biodiversity’s (SAIAB) Acoustic Tracking Array Platform (ATAP) programme donated Bob’s acoustic tag. This programme has special acoustic tag receivers installed all along the coast of Mozambique, from Cape Point to Ponta do Ouro.
“We are very grateful for their support and are confident that, if Bob remains coastal, we will be able to follow his movements for a very long time!”
Along the South African coastline, there are over 200 acoustic receivers. Bob has swum alongside over 20 of these receivers in KwaZulu Natal, recording his transmissions as he goes.
“Where might Bob go next?” Concludes Noble in her most recent update. “Will he continue to head deeper into the ocean, or will he zoom up the coastline?”
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Picture: Two Oceans Aquarium / Facebook