Scientists open 40-year-old salmon and find a surprising sign of ocean recovery

Old canned salmon turned out to be a time capsule of ocean health. Researchers found that rising levels of tiny parasitic worms in some salmon species suggest stronger, more complete marine food webs. Because these parasites depend on multiple hosts—including marine mammals—their increase may reflect ecosystem recovery over decades. What looks unappetizing may actually be a sign of a healthier ocean.