Over recent decades, many commercially harvested fish have grown slower and matured earlier, which can translate into lower yields and a reduced resilience to overexploitation.
Over recent decades, many commercially harvested fish have grown slower and matured earlier, which can translate into lower yields and a reduced resilience to overexploitation.
Scientists have long suspected that rapid evolutionary change in fish is caused by intense harvest pressure. Now, for the first time, scientists have unraveled genomic changes that prompt fisheries-induced evolution – changes that previously had been invisible to researchers, according to a study published in Science, Aug. 2.
“Most people think of evolution as a very slow process that unfolds over millennial time scales, but evolution can, in fact, happen very quickly,” said lead author Nina Overgaard Therkildsen, Cornell assistant professor of conservation genomics in the Department of Natural Resources.
In heavily exploited fish stocks, fishing almost always targets the largest individuals. “Slower-growing fish will be smaller and escape the nets better, thereby having a higher chance of passing their genes on to the next generations. This way, fishing can cause rapid evolutionary change in growth rates and other traits,” said Therkildsen. “We see many indications of this effect in wild fish stocks, but no one has known what the underlying genetic changes were.”
Read more at Cornell University
