February 13, 2018

Marine biologist to explore life cycle diversity in red seaweed

Written by

stacey krueger 2018Stacy Krueger-Hadfield, Ph.D.Red seaweeds play a critical role in economies worldwide, as they are used in hair products, toothpaste and food. A researcher in the University of Alabama at Birmingham Department of Biology received the Ray Lankester Investigatorship, which allows her to carry out research with a colleague at the Marine Biological Association of the United Kingdom.

This work will advance knowledge of how and why some invasive species with complicated life cycles are capable of spreading rapidly, and profoundly altering their new habitats.

“Algae play a vital role in marine ecosystems,” said Stacy Krueger-Hadfield, Ph.D., assistant professor in the UAB College of Arts and Sciences. “They’re even responsible for a huge percentage of the air we breathe. If these systems are disturbed by transferring various types of seaweed into novel, or foreign, ecosystems, it could change the dynamics of other organisms that live in that space.”

By understanding the differences between the free-living stages of red algal life cycles, Krueger-Hadfield hopes to identify risks and opportunities of transferring seaweed between communities. When seaweeds invade a new habitat, either naturally or through anthropogenic means, they often lose one of their free-living stages.

Why does one stage get lost more than another? That is the question Krueger-Hadfield and her team will try to figure out using mesocosm experiments. These types of experiments examine the natural environment under controlled conditions. For Krueger-Hadfield’s Investigatorship, the team will provide a link between field surveys and laboratory experiments they have done since the lab was started in 2016.

stacy kruger studentThey will see if the different life stages do better in different environmental conditions, relative to others. These data will shed light on why some seaweeds, like the agar-producing Gracilaria vermiculophylla, are such successful invaders.

“Our research is relevant beyond invasive species because seaweed farmers tend to focus on one life history stage,” Krueger-Hadfield said. “Usually, there’s one seaweed type that grows faster and has higher yield, making that the type you want to exploit.”

In placing each seaweed stage in a variety of controlled conditions (such as different temperatures and salinities), the team is seeing whether there might have been selection during the invasion for certain seaweed traits, not unlike how we have selected certain attributes in wild cabbage that gave us brussel sprouts, cauliflower and broccoli.

Their results will only pose more questions: What happens in the longer term for seaweeds that lose a free-living stage? What are the ecological impacts? The evolutionary impacts? Investigators are unsure, establishing these questions as the basis of Krueger-Hadfield’s research themes in her nascent lab.

The Ray Lankester Investigatorship provides opportunities to established researchers to work at the Laboratory of the Marine Biology Association of the United Kingdom in Plymouth, England. The Investigatorship is to advance the knowledge of marine animals and plants or further the development of marine biology.