ELLSWORTH – There is a lot we don’t know about lobsters. Shellfish are iconic here in Maine, but we’re struggling to pin down anything as basic as their age.
But maybe not for a long time. British researchers say they may have found a way to accurately determine the age of lobsters using a new DNA-based technique developed at the University of East Anglia.
Until now, researchers have come to an age of the lobster using its size. It was assumed that they could live to be 100 years old, but establishing the age could never be completely accurate as individual lobsters grow at different rates.
Lobsters have hard, inelastic shells, so as they grow they have to get rid of their old ones and replace them with new ones. Factors such as food availability and water temperature can affect growth rates, meaning not all lobsters molt at the same time.
“For a long time, it appeared that there was no precise way to quantify the age of a lobster,” Martin Taylor, a scientist in the university’s school of biological sciences, said in a statement. âSome research suggests that you can tell a lobster’s age by counting the rings in parts of its eye stems and stomach, much like counting tree rings. But you can’t do that for a live lobster.
So, Taylor and his team set out to develop a new, non-lethal way to age European lobster in the hope that it could help give more accurate population assessments and in turn allow for more sustainable management of the fishery.
In a study published last month in Evolutionary Applications, scientists used a method that relied on quantifying the changes in DNA that accumulate over time. The amount of modified methyl groups in DNA correlated with the age of the lobster.
The researchers used hatchery-reared lobsters, which allowed them to know the exact age, as well as European lobsters caught in the wild during the experiment.
âWe identified a very strong relationship between age and DNA changes, which allowed us to accurately estimate the age of individual lobsters,â Taylor said. “Applying this method to wild lobsters predicted ages that generally aligned with minimum age-at-size estimates.”
The method seems more precise for young lobsters. Researchers were able to determine the age in about a month for lobsters 51 months and younger, but more work is needed for older lobsters.
This is the first study to investigate the so-called rDNA epigenetic clock of aging in wild animals and has concluded that the method holds great promise.
âHaving an accurate indication of the age of the lobster will help fisheries, scientists and conservationists understand, manage and conserve our vulnerable lobster stocks, working hand in hand with proactive fisheries management strategies. , such as improving stocks, âCarly Daniels, the head of production science and development at the national lobster hatchery, said in a statement.
In an email, Taylor said he believes the method might work for American lobsters in Maine as well.
“The ribosomal DNA clock should in theory be applicable to American lobsters, but it should be calibrated on known age American lobsters in the same way we did in our study,” he wrote. “It may also be necessary to make changes to some methodologies due to the differences in DNA sequences between the two species.”