Baby lobsters may be adaptable to changes in Gulf of Maine, study shows
By Hannah LaClaire January 28, 2021
Baby lobsters may be more adaptable to rapidly changing ocean conditions than previously thought, according to results from a new scientific study conducted in Maine.
A juvenile lobster is shown in Harpswell in 2015. A research team has examined how post-larval lobsters genes reacted to the effects of ocean warming, acidification and the combination of both. Gregory Rec/Staff Photographer
The study, conducted by a team of researchers from the University of Maine Darling Marine Center in Walpole, Bigelow Laboratory for Ocean Sciences in East Boothbay, and the Maine Department of Marine Resources in West Boothbay Harbor, examined the effects of ocean warming and acidification on gene expression in the earliest life stages of the American lobster.
Led by recent University of Maine graduate Maura Niemesto, the team examined how post-larval lobsters genes – especially those related to exoskeleton or shell formation and immune response – reacted to the effects of ocean warming, acidification and the combination of both. The study was published in the January issue of Ecology and Evolution, a scientific journal.
Results showed that the lobsters’ genes were more responsive to elevated acidification than warmer waters, and that the two stresses created a “significantly greater” response than either of the two alone. While the ability to adapt is beneficial in a changing environment, the amount of energy required to do so could compromise the lobsters’ other vital functions.
What those compromises might be is still unknown. Another interesting finding was that ocean acidification might trigger genetic responses in baby lobsters more so than previously believed.
Studying the gene regulatory response, researchers believe, can help provide an understanding of how the species adapts to the environmental changes while still in its most vulnerable stage.
“Understanding the physiological and genetic responses to environmental change is critical to anticipate the effect of warming and acidification on lobster, and the information is needed to improve our ability to predict economic repercussions of climate change on the most valuable single‐species fishery in North America,” they wrote.
The Gulf of Maine has been warming faster than any other body of saltwater on the planet since 2004. Scientists estimate that by 2100, surface pH levels will be lower – that is, more acidic – than at any time in the past 300 million years, two or three times more so than today. The Gulf of Maine is particularly vulnerable because its colder water more readily absorbs carbon dioxide, and because increasing frequency of snow and rain flood it with more acidic river runoff.
Maine’s $485 million lobster industry is critical to the state’s economy – coupled with its supply chain, the industry pumps an estimated $1.5 billion into the state economy each year.
But despite its importance, the study’s researchers say little is known about how the species will respond to the combined effects of increasing ocean temperatures and acidification.
Some of what scientists have uncovered so far does not bode well for Maine’s economic future.
Last summer, University of Maine researchers found that lobsters living in ocean water as warm and acidic as the Gulf of Maine is expected to be by the end of this century will be less able to cope with stress or fight off disease.
While higher water temperatures and acidification both seem to hurt lobsters’ heart function and immune response individually, researchers found the combined impact of both likely end-of-century environmental conditions would leave lobsters especially vulnerable.
But this latest study provides a glimmer of hope.
The research, according to co-author Richard Wahle, “reveals some of the hidden mechanisms species employ minute to minute and hour to hour at the cellular level to function normally in a variable environment … We need to gain these insights as we take on the larger challenge of understanding how species adapt on the much larger time scale of decades.”
More testing needs to be done to see how rapidly populations may be able to adapt, as well as studies on subpopulations and multigenerational studies, Niemesto said, but the existing results are a good first step.
The research was funded by a grant from the National Oceanic and Atmospheric Administration’s Ocean Acidification Program and the National Sea Grant Program.
