Two days of non-stop rain means no diving and no new manta sightings but it also means that we have time for a much needed blog post. Today I’m going to talk about the thrilling topic of databases! Also known as “what we spend our evenings doing”. Bear with me here...
Every single manta ray has a unique spot pattern on their ventral surface (scientific word for belly). It means that if you can get a photo of it then you can ID that specific manta again and again whenever and wherever it shows up. They work just like our fingerprints. The best way of cataloguing the population of manta rays in an area is to photograph the belly of each one you see and then use the Manta Trust’s database to work out if it has been sighted before, how many times, where-abouts etc. And that is exactly what we have been trying to do in Bora Bora. The database of Bora Bora mantas goes back to 2002 when some of the original research was done on the population here so we have been comparing our belly photos to these. Some of the mantas we have encountered are new to the Manta Trust so we have given them new numbers like our most recent individual ST-MA-0137 (catchy right!)
The photo above is straight from the database gallery and shows you that ST-MA-0137 is a female with a long tail. Here we would also be able to log if she has any damage to her fins, tail or body which thankfully she doesn't! Spreadsheets within the database then tell us info like when they were first seen and where, if they've ever been sighted pregnant, their size, life stage and all sorts of other info. It's all very useful and we're excited to be able to contribute to something like this.
Some of the mantas we're seeing though have been encountered before. This week we have had two dives with a manta called ST-MA-0003. For those of you that haven’t guessed how the numbering system works this means that this particular ray was the third manta added to the database for Bora Bora. She was first seen way back in 2002, already as an adult and since female mantas reach maturity at around 15 years old then it stands to reason that she is around 30 now! She’s known as Blacky, she travels regularly between Bora Bora and Maupiti (another nearby manta spot) and is well known to manta scientists here.
On to Tikehau which is an island (or a motu as they're known in Tahitian) near to Bora Bora and part of an island group called the Tuamotus. We recently met a man called Vincent who has been working with and photographing the mantas in Tikehau for years and had hundreds of belly shots dating back to 2011. He offered us the photos to catalogue and add to a new Tuamotus database and we eagerly accepted. After a few long evenings of staring at photos of manta stomachs we have 71 new individuals logged already! Vincent has some stunning manta photos from Tikehau which we hope to share with you soon as well as persuading him to write a little guest too.
Thanks for reading,