The Intrepid, Evacuating Foraminifera who Survived a Wildfire

two 2-chambered foraminifera offspring
Light-microscope photograph of two 2-chambered foraminifera offspring with thin rhizopodial filaments radiating outward from the central shells. The thin round calcium carbonate shells appear white, with reddish cytoplasm (the soft living portion of the organism) inside the shells. The rhizopodia are thin thread-like filaments along which cytoplasm moves into and out of the shells to simultaneously collect food and bring it into the shell, and to dispose of waste products from within the shells to the surrounding water.

Through Smoke, Fire, and Evacuation

This study, titled Extensive morphological variability in asexually produced planktic foraminifera, was conducted by an all-female team of researchers: led by Kate Davis (a UC Davis Ph.D. Graduate who is now a postdoc at Yale) and Cait Livsey (UC Davis Earth & Planetary Sciences), and assisted by Hannah Palmer (UC Davis Earth & Planetary Sciences, and Bodega Marine Laboratory) and was conducted at the Bodega Marine Laboratory. It is a noteworthy story in part because of the hurdles faced by the team in order to collect this data. Starting in October of 2019, the Kincade Fire burned 77,758 acres of Sonoma County before its containment on November 6. As winds shifted on October 26th, moving the fire and the accompanying smoke-saturated air closer to the lab, Bodega Marine Laboratory was placed under a mandatory evacuation order by the county. 

However, before leaving the laboratory, Ph.D. candidate Hannah Palmer was able to rescue the remaining living foraminifera and brought them in an insulated cooler to the Earth and Planetary Sciences Department on the UC Davis campus. This was important not only to keep them safe, but also to ensure that the team would be able to continue to observe and photograph them daily in order to gather the necessary data to complete the study. As a result, the foraminifera in this experiment have not only brought understanding of their species forward, but have survived a mass evacuation as well.

Hannah Palmer
PhD. Candidate Hannah Palmer (right) rescued the remaining living foraminifera from the Bodega Marine Lab and brought them in an insulated cooler to the Earth and Planetary Sciences Department in Davis after wildfires forced the evacuation and closure of BML in fall 2019.

About the Publication

The ability of planktic foraminifera - a widespread and important plankton in the ocean - to respond rapidly to optimal conditions, even when populations are separated by great distances or where densities are too low for rapid population growth has long stumped oceanographers. By demonstrating the ability of Neogloboquadrina pachyderma to reproduce asexually, this study helps to close the gaps in understanding of planktic foraminifera and their ability to maintain genetic connectivity across distances and adapt to changing conditions. It also shows implications for the survival of foraminifera in a changing climate. Planktic foraminifera may be more resilient to global changes in the ocean since they are able to follow/track optimal conditions due to their more flexible reproductive strategy.

empty mother foraminifera shell surrounded by her smaller reddish offspring foraminifera
Light microscope image of the now empty mother foraminifera shell surrounded by her smaller reddish offspring foraminifera. Minutes earlier, the mother shell was filled with the smaller reddish “orbs”, which subsequently escaped the shell through the aperture (chamber opening). With time, the daughter foraminifera moved away from the mother shell, leaving it empty on the bottom of the vial.

 

When asked about the importance of this research Cait Livsey, one of the paper’s co-authors, explained that 

“Planktic foraminifera are the primary tool that geologists use to study past oceans - most of what we know about past ocean temperatures, salinities, circulation, productivity, global climate, etc. come from planktic foraminifera fossil shells. In order to understand the controls on the geochemistry, diversity, morphology, etc. of planktic foraminifera, we study living ones in controlled environments to refine our understanding.”

Up until now, no planktic foraminifera had ever been documented to have reproduced in the laboratory so all studies on living forams had to be done on large individuals who were collected from the ocean using a tow net and brought back into the lab to study. As a result, the earliest stages of growth were never directly studied in the lab. So in addition to determining that these organisms could reproduce asexually, it was also exciting for the team because it allowed them to observe and document the earliest life stages of planktic foraminifera for the first time.

Read the full publication here

Here is a video of a daughter foraminifera moving across the bottom of the culture vial by use of its rhizopodial network. The streaming cytoplasm can be seen along the threads of rhizopodia and within the shell itself. Video has been sped up 20x and is magnified at 20x.

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