Article image

Mussel shells are becoming highly porous due to warming waters from climate change

Mussel shells have been showing a troubling trend caused by climate change, as observed in recent findings by the American Museum of Natural History.

Over the past century, these shells have become increasingly porous. This change in mussel shell structure is largely attributed to the rising temperatures of coastal waters.

Mussels’ crucial role in ecosystems

Mussels play an indispensable and multifaceted role within their ecosystems. They serve as both environmental stabilizers and critical contributors to marine biodiversity.

Leanne Melbourne, a Kathryn W. Davis postdoctoral fellow at the American Museum of Natural History, explains the importance of mussels.

“Mussels are vital for numerous reasons: they form habitats on reefs, filter water, shield coasts during storms, and have significant commercial value,” said Melbourne.

“It’s concerning to see how human-induced environmental alterations are jeopardizing the shell formation in mussels and other mollusks. Understanding the future risks this poses is imperative,” she added.

Mussel shells reveal climate changes

The study utilizes the museum’s extensive bivalve collection, which dates back to the late 1800s. This allows researchers to track environmental impacts over time.

Previous research typically involved laboratory settings to understand how ocean warming and acidification affect mussels, known scientifically as Mytilus edulis.

However, Melbourne leveraged these historical specimens to gain insights into changes under natural conditions.

Nathalie Goodkin, a curator at the museum, emphasizes the value of museum collections in ecological studies.

“They are excellent for observing long-term changes. Natural environments expose organisms to gradual changes and multiple stressors, unlike laboratory conditions which can only isolate specific factors,” Goodkin explained.

Mussel shells comparison

The focus of Melbourne’s research was on shells collected from the early 1900s and 1960s. These specimens were gathered from five distinct locations, ranging from Nahant Bay in Massachusetts to New York Harbor.

Subsequently, Melbourne compared these historical samples with modern specimens from the same areas, assessing factors such as shell thickness, surface area, volume, and porosity.

Porous mussel shells from climate change

The study clearly showed that modern mussel shells are markedly more porous than those from earlier decades. The research suggests that rising sea temperatures, which have increased by up to 3 degrees Celsius since 1902, might be contributing to this change.

However, factors such as the North Atlantic Oscillation, which brought unexpectedly cold water temperatures in the 1960s, could also influence the variability in shell porosity.

Consequently, the increased porosity could compromise the structural integrity of the mussel shells, making them more prone to damage.

“The robustness of mussel shells is integral to the ecosystem services provided by mussel reefs. If their shells are weaker, they are more likely to break, potentially leading to the loss of these crucial organisms,” Melbourne remarked. She stressed the need for further research to explore these effects at a material science level.

Impact of climate change on mussels

Beyond making their shells more porous, climate change affects mussels in several other significant ways:

  • Reduced growth rates: Warmer waters can disrupt the growth patterns of mussels, leading to smaller sizes and less robust individuals.
  • Altered reproduction cycles: Temperature changes can impact the timing of reproductive cycles, potentially leading to mismatches in the availability of plankton needed by mussel larvae to survive.
  • Increased susceptibility to diseases: Higher temperatures can facilitate the proliferation of pathogens and parasites that can infect mussel populations, reducing their overall health and survival rates.
  • Changes in habitat: As ocean temperatures rise, the suitable habitat range for mussels can shift, forcing populations to migrate or face extinction in areas that become too warm.
  • Impact on shell composition: Apart from increased porosity, climate change can alter the chemical composition and strength of mussel shells, making them more vulnerable to predators and physical damage.

In summary, the study conducted by researchers at the American Museum of Natural History reveals a troubling trend in the increasing porosity of mussel shells along the U.S. East Coast over the past 120 years.

The findings suggest that warming waters may be the primary culprit behind this phenomenon, which could have severe implications for mussel populations and the ecosystems they support.

As climate change continues to alter marine environments, it is crucial that scientists conduct further research to better understand the specific effects of temperature change on these essential organisms and develop strategies to mitigate the potential risks to their survival and the services they provide.

The full study was published in the journal PLoS ONE.


Like what you read? Subscribe to our newsletter for engaging articles, exclusive content, and the latest updates. 

Check us out on EarthSnap, a free app brought to you by Eric Ralls and


News coming your way
The biggest news about our planet delivered to you each day