Great hammerhead and shortfin mako sharks have experienced major population declines over a 250,000-year history; that’s the finding of the first chromosome level genome sequencing undertaken for these species. The study also found that low genetic diversity and signs of inbreeding are concerning for Critically Endangered great hammerhead sharks, whose overfished populations have plummeted. With higher levels of genetic diversity, shortfin mako sharks may be more resilient to environmental change; that is, if the current fishing pressure on them is substantially reduced.
Image: Local Bahamian shark diver feeding Great Hammerhead – N.E. Youness – CC 4.0 (image cropped to square aspect from original)