Why are there mantas in "Manta Point"?

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By Daniele Zanoni

Photo by Bill James
Since the end of March/early April we have been seeing mantas (Manta birostris) in a place that is not mapped on the official guide book. This place is in a bay between Pinky Wall and Tower. Since the coral reef on the slope is not great at all, normal diving activity is not carried out in this place. Last year, by chance, we could not do the dive in Tower because of a counter current, so we decided to go reef right instead. With great surprise we met whale sharks (Rhincodon typus) and a huge number of mantas. I have of course neither scientific data nor equipment to conduct proper investigations but I might have a good speculation.
Every year around the middle of the spring we have upwelling from very deep water. Deep water has a temperature lower than the surface one. This upwell has happened every year. In 2005, 2006 and 2007 we had a sheer drop in the water temperature from 26°C to 23°C for about three weeks. Last year the temperature drop happened in May, and this year at the end of March/beginning of April. Deep waters carry lots of nutrients (phosphates, nitrates, etc). The phytoplankton (plant plankton) will enhance the primary production (photosynthesis). The zooplankton (animal plankton) will then have a lot of food as well, creating an excess of nutrient for other animals. Plankton feeders, like mantas and whale sharks, can then come and exploit the richness of the area.

There is still though a question to be answered. Why especially in this bay? The cliff at this dive site is about 50-60 metres high. Right at the beginning of it (if you come from the North) there is a gap in the cliff. In this gap you have a beach area which is about a hundred metres wide and at sea level. Since there is not that much current in the area, the portion of the sea is under direct sun light even after 12 o'clock when the sun is going towards west and the topography allows for a good upwell, the plankton thrives here more than in other sites.

I personally named this place Manta Point after the very famous dive site located in the Ari Atoll in the Maldives. Now people can enjoy seeing these sea giants in a local dive site only 20 minutes away from Naama Bay jetty.

Just a few tips for the people that have not dived with these fish before. All mantas and sharks are very sensitive to high frequency pitch sounds. That means that they do not at all like tank bangers, shakers and underwater horns. The do not like people swimming fast to them either. So in order for everybody to see and enjoy the dive, you should refrain from doing so. This year I have already done this dive five times and I saw mantas five times. Last year I had 94% success (16 out 17 times).

When you come in Sharm, ask your dive guide about this dive. It's a great third dive to finish up the day with something unusual.

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About this Entry

This page contains a single entry by Bryony published on June 8, 2009 3:42 PM.

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