Mass die-offs are now more common and have increased every year for the past 70 years due to human intervention and climate factors.
Researchers in the United States have found that there are more mass animal deaths taking place every year, according to a new study.
The University of San Diego, Yale University and the University of California, Berkeley found that birds, fish and marine invertebrates are among those which are experiencing more than a 90 percent death rate in their population.
While the reasons behind the mass die-offs are varied, the research found that environmental contamination accounted for around a fifth of them. With analysis focusing on the 1940s to the present, researchers discovered that the main culprit behind the mass die-offs was disease, which accounted for 26 percent; whereas human effects, such as environmental contamination, accounted for 19 percent. Biotoxicity, on the other hand, such as algae blooms, climate change, oxygen stress or starvation and thermal stress, jointly accounted for 25 percent of the mass kills.
Dr Adam Siepielski, an assistant professor of biology at the University of San Diego said that mass mortality events, which increased by around one event a year over the past 70 years the study covered, may not seem a lot.
While this might not seem like much, one additional mass mortality event per year over 70 years translates into a considerable increase in the number of these events being reported each year. Going from one event to 70 each year is a substantial increase, especially given the increased magnitudes of mass mortality events for some of these organisms.