In the past week rangers and scientists in the Kruger National Park (KNP) have detected a cluster of crocodile mortalities mainly in the eastern parts of the Olifants and Letaba Rivers. To date an excess of 30 carcasses have been located. Post mortems on several recently dead crocodiles reveal that the deaths were caused by a condition called pansteatitis. This condition is caused by the depletion of anti-oxidants in the bodies of these animals.
This depletion results in the hardening of the crocodile’s fat reserves into a rubber-like mass, which is unavailable for normal metabolism. It is also extremely painful and the animal loses mobility. A similar incident in Loskop Dam, in the Olifants River near Bronkhorstspruit, last year was linked to a mass die-off of fish caused by sewerage pollution that was followed by a blue-green algae bloom. The crocodiles feasted on the masses of dead fish, including the rotten fish with rancid fat.
In Kruger, to date, no direct fish die-off can be linked to this event. The scientific management and veterinary staff in Kruger will be monitoring these two river systems, as well as Kruger’s other river systems, to monitor the extent of the problem and to attempt to identify the suspected environmental cause.