Puyehue-Cordón Caulle eruption. (Part Two)

Livestock

The ash cloud led Argentina to declare a state of emergency for farmers as the prolonged eruption's continued effect on the 2 million head of sheep that graze in southern Argentina. Chubut and Río Negro Provinces had suffered five years of drought, and the ash destroyed the little pastureland still serviceable. 750,000 sheep suffered the consequences, and Rio Negro officials said 60,000 head of cattle also were "at risk." The Livestock had suffered major heart attacks and got throat cancer, which made them die. Whereas there appears to be no published support for the existence of heart attacks or throat cancer as a consequence from the exposure to ashes and causing death, there are at least 2 phenomena which play a role. For one, the physical reduction of available forage (on top of the prevailing general drought conditions) has resulted in lack of forage, and therefore, starvation with all its consequences. This was accelerated by the rapid wear of teeth from the abrasive action of ashes, and thus a reduced efficiency to forage. The second reason is that these ashes cause fluoride intoxication in herbivores, with many different symptoms, and confirmed in sheep, cattle and horses.

Wildlife

However, besides livestock, also wild species are strongly affected by the ashes. Fluoride intoxication was first discover in red deer (Cervus elaphus), with pronounced dental fluorosis. The result is formation of abnormal teeth both in physical form as well as in reduced hardness. It reduces foraging efficiency, eliminated pregnancies in subadults, and will reduce longevity by 50-75%. While the rate of fluoride intake exceeds the capacity to eliminate it, animals continue to accumulate fluoride. Before the eruption, fluoride levels in adults was about 50-60 ppm. On average, deer were judged to accumulate about 1,000 ppm per year under similar exposure to ashes, which remains the situation for many drier sites, where the winds constantly redeposit the ashes. Some deer accumulated more like 3,700 ppm per year and reached 5,175 ppm by the year 2012. This trend has remained for some areas as the most recent deer examined had adults which had reached 10,396 ppm. These high levels of fluorosis likely affect the skeleton, and a first case in deer with severe osteological pathology has been described in March 2015.