What are those big sea animals
that looks like underwater war planes? They are pelagic fish and one of the
most intriguing species; in fact this spectacular animal is highly tolerant
towards humans.
Mantas are here again this year,
actively feeding in the shallow waters of Denis Island. From late August a few
mantas have been sighted, either by diving hotel guests or by the Denis Island
diving and fishing team. An encounter with these amazing creatures is purely fortuitous
and never fails to amaze those lucky enough to experience it.
The arrivals of mantas at Denis Island correspond to the
abundance of food availability. More recently, all along the northwest beach line
of Denis island, washed-up zooplankton has been encountered suggesting its
abundance in the region.
Mantas are warm water creatures that
swim with their large pectoral fins. They have no venom or spine so they are relatively
harmless. There are two species of manta rays. The giant manta (Manta birostris) commonly has a wing span
of 4.5m (15 feet) but individuals of 9.1 m (29 feet) have been recorded, and it
can weigh up to 3 tons (6,600 pounds. The reef manta (Manta alfredi) is smaller (max disc width recorded: 5 m or 16 feet)
and it is commonly found in inshore habitats.
The presence of reef manta rays
contributes to eco-tourism in certain areas where divers and snorkelers have
the opportunity to dive in close proximity to these majestic fish. However manta
rays face a huge number of threats such as fishing (both directed and bycatch),
habitat degradation, global warming, pollution, ingestion of micro plastics and
poor protection status in most regions of the globe. The IUCN Red List has categorized mantas rays as “vulnerable”.
The
Manta Trust investigates movement patterns, feeding ecology and demography of
reef manta rays in the Seychelles region. By doing this, we hope to gain a
better understanding of the health and size of this manta population, as well
as where, how, and why these animals move through the various habitats
available to them.
Lauren Peel, a PhD student from the University of Western
Australia and associated with the Save Our Seas Foundation/Manta ray project in
the Seychelles, is very interested in setting up collaborations with researchers
and dive shops across the Seychelles in order to get them to report sightings of manta rays. This will be with the aim of obtaining an outlook of
their distribution and movement patterns. Individual mantas can be identified
through the unique pigmentation patterns on the ventral side of their bodies
and it is relatively easy to collect ID photos of them by free-diving down in
front of them as they approach and take a photo as they swim overhead.
Recently a video of a manta feeding event occurred in Denis
Island was recorded, and allowed us to identify two new manta rays and add them
to our database. This is very exciting as we previously did not know that
mantas were sighted in this area!
No comments:
Post a Comment