We are finally back from our trip to Lady Elliot Island where we had an amazing time with the mantas.
Within the first week of the trip, we manage to deploy acoustic tags on 12 individuals, clean up and put back the 5 listening stations around the island and identify all mantas encountered and photographed.
We've also started the Project Manta documentary with Kauffman Production; we manage to get some great footage of tagging and cleaning behaviour and, not surprisingly, are looking forward to the next trip. Good science and heaps of fun.
The second week was marked by the arrival of our Earthwatch volunteers who participated to our daily research activities. We were mainly focused on photo-identification and zooplankton collection.
Overall, we identified over 100 new individuals in 2 weeks!!! In fact, mantas were so thrilled to see us that weíve been seeing then every single day with up to 20 ID individuals in one dive! About 55 mantas sighted were already in the original database. We now have 318 manta rays identified and included in the database, with a 101 rays resighted twice and 50 sighted 3 times. Six individuals were seen 6 times at Lady Elliot Island back from 2007. Ellama (tagged), Hinun and Erebus seem to be quite local to the island as they have all been sighted every single year since 2007 and they were all spotted several times during our trip.
Thanks to our brand new compact camera, we managed to get some nice HD video recording of cleaning and courtship behaviour that will give us some important information on the habitat use by the rays at LEI.
Zooplankton samples were also obtained while the mantas were feeding at the surface. We are going to look at the abundance and species composition of zooplankton and the nutritional quality to investigate the manta raysí diet.
Thank you to the Earthwatch volunteers, Michelle, Richard and Andy, you were a great asset during this tripÖhelped us a lot and worked hard. Also to the Lady Elliot Island staff, thanks again for your amazing help and service, it was very much appreciated. We are especially grateful to the dive shop staff who have offered to share their records on the weather conditions and manta sightings collected daily since 2008. This kind of information combined with zooplankton data and behavioural examination will provide great insights in the reason underpinning the mass aggregation of mantas at LEI.
The next stages of Project Manta are to (1) place listening stations around North Stradbroke Island (2) gather as many photos as possible from the east coast and see if the same population of mantas observed at LEI is travelling along the coast and (3) work hard to obtain funding to add more study sites to our exciting research.
A new facebook group has been created called Project Manta - The manta rays of eastern Australia. Please feel free to join, spread the word and share your anecdotes, photos and videos.