Investigation of deaths in marine iguanas (Amblyrhynchus cristatus) on Galapagos.

Large numbers of marine iguanas (Amblyrhynchus cristatus Bell) died on the Galapagos between December 1982 and August 1983. Gross and histopathological examination of five of these animals and comparison with three 1984 individuals indicated that the former had died of starvation. This was attributed to an inability to digest new species of algae which had flourished in the sea because of a rise in temperature associated with the El Niño-Southern Oscillation event in 1982 to 83. In 1984 to 85, after El Niño, conditions on the islands returned to normal; the original algal flora began to predominate and the iguana population showed a marked recovery, with increased rates of growth, survival and reproduction.