Thursday February 22, 2024
University of Massachusetts, Amherst —
A collaborative team of scientists led by the University of Massachusetts Amherst recently found that there is no physiological evidence supporting a leading theory— which involves the surface area of fish gills —as to why many fish species are “shrinking” as waters grow warmer due to climate change.
Known as the Gill Oxygen Limitation (GOL) theory, it has been proposed as the universal mechanism explaining fish size and has been used in some predictions of future global fisheries yields. However, the researchers, representing the National Oceanic and Atmospheric Administration, U.S. Geological Survey, the University of California Davis as well as UMass Amherst, conducted a series of long-term experiments on brook trout and found that, though increased temperatures do lead to significantly decreased body size, gill surface area did not explain the change. The results of the study were recently published in the Journal of Experimental Biology.
“We know that global climate change is happening and our oceans and rivers are getting warmer,” says Joshua Lonthair, lecturer in biology at UMass Amherst and the paper’s lead author. “And we know that many animals—not just fish—are growing to smaller adult body sizes under warmer temperatures. We even have a name for this, the Temperature Size Rule. But despite decades of research, we still don’t understand why size decreases as temperature increases.”