Djibouti expedition draws near

As most people get into the pre-Christmas rush of last minute card writing and present buying scattered around the world a dozen or so people are getting excited about another activity to take place shortly afterwards, the whale shark expedition to Djibouti starting on New Years Day!

Both of the two weeks of the expedition are now fully booked with the team from MCSS and Megaptera being joined by cameraman Dan Beecham and photographer Thomas Peschak from the Save our Seas Foundation as well as a total of some six eco-volunteers. Life aboard the Deli is going to be pretty hectic from the sound of things…

The expedition is going to be targeting the Arta area in the Gulf of Tadjoura which is the gulf on which Djibouti city is located just past the southern end of the Red Sea. This gulf is an inlet of the Indian Ocean caused by the fault line of the northern end of the great East African Rift Valley that transects Djibouti, Ethiopia and Kenya.

The area is geologically and volcanically active as evidenced in 1978 by the eruption of the Ardoukoba volcano. The seabed shelves steeply from the coast of the Gulf dropping to 100 m depth around two km offshore and to around 450 m depth in the centre of the Gulf of Tadjoura. The volcanic lanscape is dramatic if somewhat stark and the volcanic activity has narrowed the gulf down to form the ‘Devils Goblet’ and then pinched it off entirely leaving Lac Assal completely land locked and evaporating away. The surface of this lake is now 450 m below sea-level and the evaporating seawater has left vast salt pans with dramatic areas of salt crystal structures; this is a must for all visitors to the area and a half day trip has been planned.

The whale sharks in Djibouti are interesting in that they spend a lot of time vertical feeding and at night are drawn in to feed on swarms of tropical krill that are attracted by the boats lights...

Five whale sharks feeding on tropical krill at night... not quite sure how we would get the photo IDs done on this lot!

Off special interest to the whale shark team is the fact that very deep water is close to shore. This feature coupled with the fact that on the previous expedition in 2006 the aggregation of sharks was found to be composed of very small sharks, with several of just over 2 metres, may indicate that this area may be a nursery ground for whale sharks. The rationale for this is that globally the number of neonatal (less than 1 metre) whale sharks seen is tiny, less than 15 records, this despite the high level of fishing in coastal areas. This has prompted the idea that when first born the 65cm pups stay in very deep water to keep away from other predators and only come into shallow waters when they are around 4 m in size. Djibouti with its aggregation of very small sharks may thus be an area close to where the youngsters are.

While our team aren’t able to get to those sorts of depths, an ROV can and the BBC Natural History film unit just happen to be in Djibouti at the same time and happen to have an ROV! Their main aim is to explore the beginning of the East African Rift but having heard of our expedition and the potential of this being a nursery area they are going to see if they can find any baby whale sharks at the same time!

So this really is going to be quite an adventure... we will post news to the blog but as there is no internet connection it will probably be once we get back to civilisation...