Research reveals genetic response of ocean warming and acidification in American lobster

 A team of researchers from the University of Maine Darling Marine Center in Walpole, Bigelow Laboratory for Ocean Sciences in East Boothbay and Maine Department of Marine Resources in West Boothbay Harbor recently published their research on the effects of ocean warming and acidification on gene expression in the earliest life stages of the American lobster.

The work was published in the scientific journal Ecology and Evolution with collaborators from the University of Prince Edward Island and Dalhousie University in Canada.

Leading the study was recent UMaine graduate student Maura Niemisto, who received her master’s degree in marine science. Co-authors on the journal article were her advisers Richard Wahle, research professor in UMaine’s School of Marine Sciences and director of the Lobster Institute, and David Fields, senior research scientist at Bigelow Laboratory for Ocean Sciences. 

Co-authors Spencer Greenwood of the University of Prince Edward Island and Fraser Clark of Dalhousie University brought the genetic expertise to the study. Jesica Waller of the Maine Department of Marine Resources conducted some of the initial studies that led to Niemisto’s experiments, also in the laboratories of Wahle and Fields. 

The team’s experiments examined the gene regulatory response of postlarval lobsters to the separate and combined effects of warming and acidification anticipated by the end of the 21st century. They found that genes regulating a range of physiological functions, from those controlling shell formation to the immune response, are either up- or down-regulated. Importantly, they observed that the two stressors combined induced a greater gene regulatory response than either stressor alone.

The results from the study indicate that changes in gene expression of postlarval lobster may act as a mechanism to accommodate rapid changes in the ocean environment. Niemisto noted that “there is still need for further study to determine how rapidly populations of the species may be able to adapt to changing conditions. To better understand how gene regulation in response to environmental changes functions within the species, we should look at subpopulations and multigenerational studies to determine the extent of species’ capacity to respond to altered environmental conditions.”

“Maura’s study 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,” said Wahle. “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.”

According to the National Marine Fisheries Service, the American lobster fishery is the most valuable in North America. The species holds particular socioeconomic importance in the Gulf of Maine, where sea surface temperatures are increasing at a rate faster than most of the world’s oceans and waters are more susceptible to higher rates of acidification.

The center of the American lobster range has been shifting northward in response to warming ocean temperatures. However, little is known about how the species will respond to the combined effects of increasing ocean temperatures and acidification. This study is a first step in answering that question. The species’ earliest life stages are thought to be especially vulnerable to these climate related challenges.

The research was supported by a grant from the NOAA’s Ocean Acidification Program and the National Sea Grant Program. Additional funding for student internships came from Bigelow Laboratory’s Research Experience for Undergraduates program, supported by the National Science Foundation.

Contact: Matt Norwood, matthew.norwood@maine.edu; 207.563.8220