Archival photographs spanning more than five decades reveal a drastic decline of so-called "trophy fish" caught around coral reefs surrounding Key West, Florida.
Loren McClenachan, a graduate student at the Scripps Institution of Oceanography at the University of California, San Diego, estimates that large predatory fish have declined in weight by 88 percent in modern photos compared to black-and-white shots from the 1950s. The average length of sharks declined by more than 50 percent in 50 years, the photographs revealed.
The study mirrors others that reveal stark changes to animal sizes caused by hunting or fishing, in which the largest of a species are often sought as trophy specimens.
McClenachan's findings will be published in the journal Conservation Biology. In a companion paper being published in the Endangered Species Research journal, McClenachan used similar methods to document the decline of the globally endangered goliath grouper fish.
"These results provide evidence of major changes over the last half century and a window into an earlier, less disturbed fish community," McClenachan writes.