A rockfish born in 1878 was still in a federal fish archive 144 years later, in the form of an ear stone. NOAA Fisheries says the otolith came from a fish collected in 2022 during a survey in the Aleutian Islands, estimated at 144 years old, and that it is the oldest fish ever aged at the Alaska Fisheries Science Center. It sits among about 2.5 million pairs of otoliths that the center built up over four decades.
The specimen is the standout detail of a NOAA feature on the archive, which now lives in Seattle.
The 1878 rockfish and the rings that dated it
Otoliths are calcium carbonate stones in a fish’s inner ear. They add layers as the animal grows, and NOAA’s explanation of fish aging compares counting the annual bands to counting rings in a tree, done under a microscope at 6 to 40 times magnification. Scientists assign every fish a January 1 birth date so that cohorts line up, which is why the rockfish, collected in 2022 and aged at 144, is recorded as born in 1878 rather than at some date in between.
NOAA’s feature story does not name the species of the 144-year-old fish, but it points to why such ages are plausible: rougheye rockfish can reach projected ages of 205 years. Long-lived species make the archive unusually valuable, because a single otolith from an old fish carries a chemical record of the water it lived in across more than a century. Katherine Maslenikov, the ichthyology collections manager at the Burke Museum of Natural History and Culture, offered a comparison: an otolith collected in 1980 from a 150-year-old rockfish would hold ocean chemistry going back to the Industrial Revolution.
2.5 million pairs from 83 species
The size of the collection comes from routine work. NOAA says roughly 45,000 specimens arrive each year from fishery observers and research surveys, and the Alaska center’s staff examines more than 30,000 of them annually,. Over four decades, NOAA reports, those surveys produced an archive of 2.5 million otolith pairs dating to the 1960s, drawn from 83 species across Alaska, California, the Gulf of Alaska, the Aleutian Islands, the Bering Sea and the Arctic Ocean. The species list includes walleye pollock, sablefish, Pacific cod and shortraker rockfish.
The figure counts pairs, so the number of individual ear stones is higher than 2.5 million. The Burke Museum’s own ichthyology collection page gives a slightly lower count of approximately 2.4 million pairs and calls the otolith holdings one of the largest of their kind in the world, noting they are not currently searchable online. The two institutions agree on the origin: Alaska center personnel gathered the material over about 40 years, much of it through the North Pacific groundfish observer program. Burke describes the museum’s overall fish collection as the largest in North America by specimen count, at more than 12 million preserved specimens, and says a National Science Foundation grant paid for folding the NOAA otoliths into it in 2012.
From a 1930s hangar to the Burke Museum
For years the otoliths were kept in a wooden hangar built in the 1930s at the Western Regional Center in Seattle. In 2012, NOAA and the Burke Museum moved about 2 million pairs into the University of Washington Fish Collection, where boxes of otoliths are now housed.
Derek Chamberlin, a supervisory research fisheries biologist at NOAA, called otoliths “a perfect little time capsule,” and said the samples give the agency insight into the health and productivity of fish populations. That health question is the day job. As the Alaska center’s aging program page explains, age composition tells assessors whether a population holds a mix of old and young fish, and that informs the catch limits set each year for pollock, sablefish, Pacific cod, Pacific ocean perch and other stocks.
Uses beyond counting years
The stones have a widening set of uses. NOAA’s feature lists age and growth rates, diet reconstruction and migration tracking, along with ocean chemistry, and says they are used to underpin bomb radiocarbon age validation, in which radiocarbon from Cold War nuclear tests acts as a dated marker inside the otolith. Researchers are also testing AI-assisted aging with near-infrared spectroscopy, and the material has drawn paleontological and archaeological interest.
The 144-year age itself is an estimate, produced by ring counts rather than a birth certificate, and NOAA describes the specimen as “estimated to be 144 years old.” The story does not say whether the 1878 fish has been validated with radiocarbon. Historic specimens older than three years have left the center’s own books, and the Alaska center’s online otolith inventory, which covers Bering Sea, Aleutian Islands and Gulf of Alaska samples, notes that they now sit at the Burke Museum.
This article was produced with the assistance of AI and reviewed by Morning Overview editors prior to publication.
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