Study Reveals Marine Animals Are Shrinking Due to Climate Change
Climate change is not only increasing ocean temperatures but also triggering a shrinkage in the body size of marine animals. This finding comes from research analysing changes in the size of marine organisms over approximately 450 million years, indicating that this phenomenon is becoming more extreme during periods of global warming.
Research conducted by the Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), the University of Warsaw, and the University of Lille found that various marine animals, such as molluscs, crustaceans, and fish, tend to shrink when facing environmental crises. This phenomenon, known as the Lilliput effect, is considered one of the biological responses to environmental pressure.
The research team analysed nearly 9,000 data points on changes in marine animal body size, ranging from fossil records and historical records to modern observations. The results, published in the journal Proceedings of the National Academy of Sciences, show that global warming is a factor that intensifies the shrinkage of marine organism body sizes.
“Our data show that the reduction in body size is a common response of marine animals to environmental crises. We observed this phenomenon across highly diverse animal groups, ranging from dwarfing in certain species to the dominance of small-sized species across entire ecosystem communities. The shrinkage in body size is a strong signal that ecosystems are undergoing severe stress,” said the study’s lead author, Paulina Nätscher, as quoted from Phys.org.
Kenneth De Baets, a researcher from the University of Warsaw, explained that body size shrinkage occurs during almost all environmental crises. However, the impact becomes much greater when the crisis is triggered by rising Earth temperatures.
“In all environmental crises, whether triggered by temperature warming or not, body size shrinkage certainly occurs within biological communities,” said Kenneth.
According to him, extreme global warming triggers larger changes in body size at the species level. “What is most striking is that crises with extreme global warming trigger much stronger and more varied changes directly within the species themselves, or in other words, trigger noticeable dwarfing. On average, the impact of this shrinkage is twice as severe during warming phases compared to other environmental crises,” he added.
Wolfgang Kieß_ling, Head of the FAU Ancient Environmental Analysis Unit, stated that the link between rising temperatures and the shrinkage of marine animal body size is very clear in Earth’s historical records. “The higher Earth’s temperature rises, the more extreme the shrinkage of marine animal body size becomes. Earth’s history thus provides a stern warning for the future of our oceans,” said Wolfgang.
The study concludes that the trend of shrinking fish and marine invertebrate sizes currently being observed in various regions is not merely a temporary phenomenon, but part of a pattern that has repeated throughout Earth’s geological history. If global warming continues, smaller body sizes in marine organisms are expected to become increasingly common, potentially affecting marine food chains and global fishery productivity.