Climate Change Causes Marine Animals to Shrink in Size

A comprehensive study analyzing nearly 9,000 instances of marine body-size change over the past 450 million years finds that shrinking sizes are a widespread response to environmental crises. Researchers compiling fossil records, historical data, and modern observations report two consistent patterns: communities shifting toward smaller species and dwarfing within the same species. The strongest reductions align with warming episodes, with Dr. Kenneth De Baets saying size changes tied to pronounced heat are about twice as intense as other crises. Professor Wolfgang Kießling is cited for a correlation in which the magnitude of size decline scales with the degree of temperature increase. The work, conducted by researchers from FAU and the University of Warsaw, warns that today’s anthropogenic warming could drive similar widespread diminutions. Over time, smaller sizes may disrupt marine food webs and affect fisheries through reduced stock biomass and yields.