Mass die-offs of certain animals has increased in frequency every year for seven decades, according to a new study. Researchers found that such events, which can kill more than 90 per cent of a population, are increasing among birds, fish and marine invertebrates. The reasons for the die-offs are diverse, with effects tied to humans such as environmental contamination accounting for about a fifth of them. Three US institutions say mass die-offs are now more common. They have increased by one event per year for 70 years. Pictured are dead tilapia floating near Salton Sea Beach in California, US on 19 Januray 11. They were killed by erosion and high toxicity levels from farm runoff
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Three US institutions say mass die-offs are now more common
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They have increased by one event per year for 70 years
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Although not as deadly as an extinction they can kill 90% of a population
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Reasons include human intervention and climate factors
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The worst cases were the result of multiple causes
@placeholder mortality events occur when a large percentage of a population dies in a short time frame.