Food Web Dynamics

CMOP intern Aric Washines from Heritage University inspects rotifers, a minute multicellular aquatic animal of the phylum Rotifera that he grew in the lab.

Aric joined Dr. Tawnya Peterson and her graduate student Michelle Maier to study the food web dynamics in the Columbia River.  His summer project shed light on the role that chytrid zoospores (fungal parasites of key primary producers) play in the Columbia River aquatic food web by comparing the growth of rotifers when fed zoospores versus microscopic algae.

Rotifers live in the Columbia River and may be a food source for juvenile salmon and their prey. He cultured rotifers in the lab and observed how well they did when consuming phytoplankton that were infected by chytrid fungi and those that were not.

“Rotifers are fairly hearty, but if the temperature, ammonia, oxygen, or pH levels are wrong the population could crash quickly,” Aric said. “Learning how to grow and maintain rotifers at a healthy level was an experiment itself.”