Today we had a class with Andy for 2 sessions. The first session was an Introduction to Manta Rays. We learned a lot about manta behaviour, taxonomy, and their life cycle. There was so much that I didn’t know before, and it interests me and all of the interns. We learned that every manta has unique markings on their stomach and like a fingerprint for humans allows us to identify mantas. Mantas can live for 40+ years, they eat zooplankton, they give birth to 1-2 baby mantas every 2-5 years, and they have the biggest brain to body ratio of all fish. There are 2 species of Mantas, Manta alfredi and Manta birostris. There are also many other fact that are still a mystery, like why mantas jump to the surface like flying? Or are there other manta species still to discover? So interesting, right?
The next session we learned about Manta Conservation. There are 3 point of Manta’s Value. First, The Ecological. Mantas are role player for carbon cycle at the ocean, like all planktivore creature. Indirectly they transferred the carbon from the atmosphere to the sea bottom. The other point is Cultural. The boy in Flores won’t be a man if they haven’t caught Manta. I don’t know if it’s good for Mantas, but if the boy can’t admit as a man, it’s sad, either if Mantas killed. The last point is the economy. It can be more profitable if we develop Mantas for ecotourism site instead of catch them to consume.
We also learned about the risk and impact of environmental change on mantas. We made a little discussion about some issue that we’d never thought of before. Manta wings are being used to replace the demands for shark fin soup as shark populations decline, and manta gills are believed to be medicine, even though there’s no fact from research about it. We discussed many other issues and tried to think about the solutions.
Next Elitza taught us about diving responsibility, good buoyancy techniques, and how to do a buoyancy check. We learned a lot about how we should control our buoyancy by just exhaling and inhaling. Check how much weight we need to make good buoyancy and why we must have good control buoyancy for Manta survey. Back to the field, Pulau Bidadari became our diving training site. We deflated our BCDs with minimum weight and see how deep we sank and some other technique. It’s a little hard for me to stay at the bottom while exhale and the air still in BCD. Maybe I need more weight, more practice, or more diving. We played some game too. Actually I want to play the Hot Potato with good exhale-inhale technique, but I just moved the weight without felt how I was breathing, like it was a real hot potato.
The last, we dove to train our buoyancy and streamline position while swimming. It’s a little bit hard for me to control my buoyancy when in slope bottom, but Eli led us to that area and I think it’s easier when I don’t kick a lot, stay streamline, and keep the distance between my body about half meter to the bottom. The other interns did it well like expert. Then I made a mistake again (after I left my mask). I used my emergency sausage and I ascended faster when we’re doing safety stop. Fortunately I could descend and no decompression sign from the dive computer. I made a mistake but we can learn something new about Do-and-Don’t in diving. So we’re ready for manta survey lesson and I can’t wait to see the Mantas!
