GVI Kenya

Category: Dolphins | Date: Apr 22 2008 | By: admin

Even without our research boat at sea every day, vital data on dolphins around the Kisite Mpunguti Marine Protected Area has been collected in the last couple of weeks. Despite the rather sad circumstances, it is still very exciting to report that we now know of a fourth species of dolphin present in the area. 

Above: KWS arrive at the stranded dolphin in Gazi 

Upto know GVI Kenya has been able to postively identify and record the distribution of three species here - Indian Ocean Bottlenose dolphins and Indo-Pacific Humpback dolphins are found year round, whilst the mesmerising Spinner dolphins visit us in February and March, performing their acrobatic spinning leaps. We can now add a fourth species - Risso’s dolphin (Grampus griseus).

Above: the dolphin is carried to deeper water - ideally it would be carried in a special stretcher and kept upright, shaded and covered in wet towels but KWS and the local people on hand to help had to do the best they could 

A couple of weeks ago, the KWS team in Shimoni were called to assist a stranded dolphin at Gazi, a half hour up the coast. GVI’s Rachel was contacted for advice on how to handle it as there is very little expertise or training here to deal with dolphin strandings. Jillo Katello, from the KWS research team, and former scholarship student with GVI, was on hand to the do the best they could, carrying the dolphin to shallow water and holding it at the surface to breathe. After a few hours the distressed dolphin had calmed down and swam away.

Above: The dolphin is held in the water and kept balanced to ensure it can breathe through its blowhole 

Sadly the next day it was found washed up again having died. Remarkably, within a week a second Risso’s dolphin was found dead here in Shimoni. At this point we have no reason to suspect anything other than natural causes for these two deaths - there was no indication of entanglement in fishing nets which is one of the most widely known threats to this species. However tissue samples were taken to Kenya Marine and Fisheries Research Institute for analysis. 

Above: Jillo from KWS with the Risso after it was found dead the following day 

Risso’s dolphins are a large robust species, reaching close to 4m in body length. They favour deeper waters with steep shelves, 400m - 1000m in depth, feed mainly on squid, making it unlikely that we would find them in the shallower waters close to the coast. As you can see from the photos they are easily distinguishable from our other dolphins here as they do not have the long thin rostrum or ‘break’ of the other species, but instead a rounded, rather blunt head. The many scars that can be seen are also typical of this species and not something to be alarmed about, it is thought they acquire them with age through social interactions. 

Above: A second Risso was found dead at Shimoni just one week later. The many white scars are natural and characteristic of the species