Sea Turtle Tracking

The image below is a preview of the original file in PDF that you can download and zoom in here

Interesting observations by looking at the data (as of 6/2022)

  • Most of the turtles have been identified in the period 6/19-6/22, plus some coming from pictures retrospectively collected from 2015 to 2019.

  • 85% of them are Green Turtles (Endangered) and 15% Hawksbill (Critically Endangered).

  • A number of sea turtles stayed in one site for weeks or months before disappearing and then reappearing months after in the very same place.

  • No turtle has ever been found in more than 1 of the 12 sites monitored: either they don't move from their elected site or they leave the region, and when they return they pick always the same site.

  • July has been the month with more individuals spotted (see graph above), which is interesting considering that the natural drop of divers during the cold season would have suggested otherwise.

Sea Turtles are found within a huge range of latitudes, from Japan to our coast all the way down to Narooma. For many countries, seeing a sea turtle in the wild is synonymous of extensive travelling to tropical destinations, but thanks to the East Australian Current we find them right at our doorstep, for the very last bit of their North-South migrations.

These are the different individuals that we have been able to identify by collecting and analyzing all the pictures posted on VIZ.

By comparing the patterns on the skin and the shell we can link a sighting (picture) to a sea turtle in our database or create a new record if there is no match. The goal is to have a sense of how many different sea turtles are spotted in Sydney and how long they stay, which is an information that has never been available before.

The project has been running since the start of the VIZ group in June 2019. It's a significant investment of time, but it allows to preserve and share the information contained in the visibility reports, that otherwise would sink into oblivion in the Facebook feed.

Check out the other derivate we produce from visibility reports: the VIZ Tracking Project

The turtle presence across time (green) and the time spent in rehabilitation (yellow). The table spans to before the start of the project (6/2019) thanks to additional pictures that we have been collecting retrospectively

A graphic produced by VIZ to inform swimmers and divers