86 dolphins were found dead on an island near the coast of Mozambique, the country’s Ministry of Environment announced Tuesday. The cause of their death is still not known. Several dolphins had already been found dead at the same location Sunday. In total, 111 marine mammals were s found by authorities. The archipelago is located in the Mozambique Channel, between the coast of the country and Madagascar. A probe is underway to determine the cause of the death of the marine animals. The team of researchers sent to the field found no trace of injury on the dolphins, nor any suspicious substance in their digestive system, the authorities said in the statement. The Bazaruto Archipelago National Park is the first marine park in Mozambique. Its protected waters are home to many marine mammals such as dolphins, whales and dugongs. It is also home to 180 species of birds, 45 reptiles, 16 types of land mammals, as well as 500 marine and coastal species and 2,000 fish.