New Study Finds These Tropical Fish Can Live To Be Over 80 Years Old

 How long do fish live? 10 years? Twenty? Try more than 80 years, according to new research on snappers.

Before now, the oldest known snapper was recorded at age 60, two decades younger than the findings recently published in the Journal Coral Reefs. Does this twenty-year age difference matter? According to fisheries scientist and lead author of the study, Dr. Brett Taylor, it matters quite a lot.

Snappers serve as an important food source worldwide. Despite the importance of snapper, the global snapper fishery is largely poorly managed. This, combined with the high market value of some snapper species, led the U.S. National Oceanic and Atmospheric Administration (NOAA) to officially label red snapper as "at risk" for illegal, unreported and unregulated (IUU) fishing and market fraud in 2015.

A close-up, side-angled view of a snapper.

One of the two species of snapper (Lutjanus bohar) new research found that it is more than 60 years old - ... [ + ] BRETT TAYLOR

Snappers were known to be "long-lived" species before the recent discovery of 80-year-old fish. In fact, the long lifespan of snapper is part of what makes fish susceptible to exploitation. "There is a direct relationship between lifespan and how quickly a population can replenish through reproduction," Taylor explains. "Long-lived marine fish have developed a strategy that allows them to cushion periods of poor environmental conditions by having many mature and spawning individuals present in the stocks. This strategy, however, did not evolve along with the additional pressure of fishing, which directly removes these larger and older fish from the population.”

To better understand the effects of fishing, and potentially overfishing, on snappers, Taylor and his team studied three species of snappers that are not fished commercially or recreationally. "This allowed us to examine something more similar to 'natural population structures' that have not been truncated or otherwise affected by fishing pressure, " Taylor explains. In the absence of fishing pressure, knowledge of the age of these snapper species compared to commercially harvested species could provide important information on the effects of fishing on exploited snapper stocks.

The biggest fish are women

A rocket from the 1966 Surveyor 2 mission has revisited

What you need to know about Pfizer's Covid-19 vaccine

In addition to studying the age of the three snapper species, Taylor and coauthors looked at whether snapper growth rates or shelf life changed with different temperatures. In hot climates, cold-blooded animals such as fish must use extra energy to compensate for their warm environment.

A cut tree trunk, showing the age rings of the tree.

Scientists use fish ear stones, or otoliths, to estimate the age of a fish in a similar way to ... [ + ] GETTY

Before the widespread use of the use of fish ear stones (otoliths) to determine the age of a fish, in a not-so-different way of counting the rings inside a tree, scientists largely thought that tropical fish were relatively short-lived species. "However, seminal research in the 1980s and 1990s showed us that many types of tropical reef fish have extended lifespan, far beyond what we previously assumed," Taylor explains.

While Taylor's research revealed record ages between two of the three species of snapper studied, the relative impact of temperature on fish ages and growth rates matched expectations, with snapper living in warmer waters tend to grow faster but have a shorter lifespan.

However, Taylor says these results will be important in informing future fishing models to better predict snapper growth under climate change. "Body size translates into meat, which translates into money and livelihood in fishing, and shelf life influences the productivity of the population," explains Taylor. "Therefore, the way species respond biologically to warming ocean temperatures could have serious implications for Fisheries harvests.”