To survive a changing ocean, it can help to be asexual, at least if you’re a planktic foraminifera. That’s according to a study of the one-celled organisms conducted at the UC Davis Bodega Marine Laboratory.
From the deep ocean to intertidal marshes, foraminifera have existed for more than 500 million years in all types of marine environments. One reason for their staying power may be due to a flexible reproductive strategy, found the study, which was published in the journal Science Advances.
The study found that planktic foraminifera reproduce both sexually and asexually. This helps explain how they’ve been able to rapidly respond to changes in their environment, even when separated by great distances. This strategy may also help them be more resilient to global changes in the ocean, the study suggests.
What are foraminifera, and why are they important?
Neither plant nor animal, these tiny one-celled organisms are important sources of food for marine snails, sand dollars and small fish. Their fossils provide evidence about past environments, including water chemistry and temperature changes, and they play an important role in marine carbon cycling.
“Planktic foraminifera are the primary tool that geologists use to study past oceans,” said co-author Caitlin Livsey, a Ph.D. candidate at UC Davis. “Most of what we know about past ocean temperatures, salinities, circulation, productivity, global climate, etcetera, comes from planktic foraminifera fossil shells.”
Yet little has been known about their life history, heritability and how their surrounding environment shapes their diversity, which this study helps inform.
In addition to finding that these organisms could reproduce asexually, the team was also excited to be the first to document the earliest life stages of planktic foraminifera in a lab. Previous studies on living foraminifera missed their earliest stages of growth because the studies were of adult individuals collected from the ocean.
This study’s foraminifera and the researchers underwent climate-related stress when wildfires and accompanying smoke in October 2019 resulted in the Bodega Marine Laboratory being placed under mandatory evacuation.
Ph.D. candidate Hannah Palmer evacuated the foraminifera and brought them to the Earth and Planetary Science Department on the UC Davis campus. This kept them safe while also allowing the research team to continue to observe and photograph them each day to collect the necessary data.
Read more about the evacuation and the study in the article “The Intrepid, Evacuating Foraminifera who Survived a Wildfire” at the UC Davis Coastal and Marine Sciences Institute’s website.
The study’s additional authors include lead author Catherine Davis, a UC Davis Ph.D. graduate currently at Yale University; Pincelli Hull of Yale University; Ellen Thomas of Yale and Wesleyan University; Tessa Hill of UC Davis, and Claudia Benitez-Nelson of University of South Carolina, Columbia.