After being here for 2 weeks, I have already seen marine life that you wouldn’t see on most dives such as green and hawksbill turtles, reef sharks, devil, eagle and manta rays and I better not forget the Bumphead Parrotfish and Humphead Wrasse – and remember I am only at the beginning of my third week! However when I thought I couldn’t see anything else, that is when I got the ‘once in a lifetime’ opportunity to swim with the oceans most mysterious and gentle giant, the Whale Shark.
Whale Sharks are seasonal visitors to the Seychelles, generally appearing in coastal waters between the end of August to October. However, in some seasons, there may be a few Whale Sharks coming in from deeper oceanic waters in June. Whale Sharks sightings in coastal waters generally coincide with an oceanic upwelling event bringing cold, nutrient-rich water up from the deeper regions to surface waters. These nutrient-rich water bodies are moved onto the continental shelf by south-easterly winds which in turn create ideal conditions for plankton blooms. As Whale Sharks are filter feeders, they love plankton blooms and follow these blooms into shallow coastal waters – this is where we come in!
Every time a Whale Shark is sighted within coastal waters, certain information about that individual is recorded such as length, sex, behaviour and a photograph is taken to identify the Whale Shark. The photograph can be taken on either side of the Whale Shark but it needs to be behind the gill slits and above the pectoral fin (see figure below). Within this area shows a spotted pattern which is unique to that individual and using a specialized program it gives an indication to researchers whether this individual has been seen in coastal waters before in a previous season.
At GVI, every time a Whale Shark is sighted, the image and information is sent to the Marine Conservation Society of the Seychelles (MCSS) to be added to their database of Whale Shark sightings and help contributed to their ongoing Whale Shark research. The MCSS is the leading non-government organisation in Whale Shark research in the Seychelles and through providing them with our various sightings helps contribute to their knowledge of Whale Shark movements and behaviours.
So on a parting note and until next time, these animals are incredibly majestic and having experienced swimming with these magnificent giants, it will be a moment that will be very hard to beat but will be carried with me for life.