A healthy starfish exists in Ian Hewson’s lab. Sea stars along the Pacific Coast are not so lucky, as big quantities of raw material might be robbing them of a capability to breathe. Credit: Ian Hewson Laboratory
For more than 7 years, a mystical losing illness has actually almost exterminated sea star populations around the globe. Some of these types stand at the edge of termination.
New Cornell-led research study recommends that starfish, victims of sea star losing illness (SSWD), might really remain in breathing distress – actually “drowning” in their own environment – as raised microbial activity stemmed from close-by raw material and warm ocean temperature levels rob the animals of their capability to breathe.
“As humans, we breathe, we ventilate, we bring air into our lungs and we exhale,” stated Ian Hewson, teacher of microbiology in the College of Agriculture and Life Sciences. “Sea stars diffuse oxygen over their outer surface through little structures called papulae, or skin gills. If there is not enough oxygen surrounding the papulae, the starfish can’t breathe.”
The research study, “Evidence That Microorganisms at the Animal-Water Interface Drive Sea Star Wasting Disease,” was released on January 6, 2021, in the journal Frontiers in Microbiology.
According to Hewson, ocean conditions result in the production of uncommon quantities of natural product, which he stated triggers germs to grow. As germs take in the raw material, they diminish the oxygen in the water – developing a low-oxygen micro-environment that surrounds starfish and causes deflation, staining, puffiness, and limb twisting or curling.
“It’s a cascade of problems that starts with changes in the environment,” Hewson stated, describing that the majority of the raw material originates from tiny algae exudation (a discharge), zooplankton excretion and egestion, and from decomposing animal carcasses. This promotes a group of germs called copiotrophs, which make it through on carbon and quickly take in raw material, he stated.
The copiotrophs respire, he stated, so while soaking up the raw material, they diminish oxygen in the sea star’s watery area.
“It’s organic matter concentrations in the water,” he stated. “If you have a dead and rotting starfish next to starfish that are healthy, all of that dead one’s organic matter drifts and fuels the bacteria, creating a hypoxic environment. It looks like disease is being transmitted.”
Hewson stated that while more clinical work should be done, “This reframes the discussion about marine disease ecology, which has focused on pathogenic disease,” he stated. “We should now include microorganisms that don’t directly cause the pathology, since they may hold a key to affecting sea star health.”
Reference: “Evidence That Microorganisms at the Animal-Water Interface Drive Sea Star Wasting Disease” by Citlalli A. Aquino, Ryan M. Besemer, Christopher M. DeRito, Jan Kocian, Ian R. Porter, Peter T. Raimondi, Jordan E. Rede, Lauren M. Schiebelhut, Jed P. Sparks, John P. Wares and Ian Hewson, 6 January 2021, Frontiers in Microbiology.
DOI: 10.3389/fmicb.2020.610009
In addition to Hewson, Cornellians on this research study consist of Christopher M. DeRito, scientist, Department of Microbiology; Ian R. Porter, assistant scientific teacher, College of Veterinary Medicine; Jordan E. Rede, college student, Department of Microbiology; and Jed P. Sparks, teacher, Department of Ecology and Evolutionary Biology.
Other factors are Citlalli A. Aquino, college student, San Francisco State University; Ryan M. Besemer, undergraduate trainee, University of North Carolina at Wilmington; Jan Kocian, scuba diver and professional photographer; Peter Raimondi, teacher, University of California Santa Cruz; Lauren M. Schiebelhut, postdoctoral scientist, University of California, Merced; and John P. Wares, teacher, University of Georgia.
The research study was supported by the National Science Foundation and the U.S. Geological Survey.
