Close up of brittlestar Asteroschema sp. on the coral Callogorgia on the seafloor.

Close up of brittlestar Asteroschema sp. on the coral Callogorgia on the seafloor. Click image for larger view and image credit.


People and Careers: Walter Cho

Sheli Smith
PAST Foundation

Growing up near the Pacific Ocean in Oxnard, California, Walter Cho always loved the ocean, so going into biology in college was not a big leap. However, Walter took a huge step crossing the country to pursue biology at Harvard. There, his professor involved him in a genetics study of shrimp in the Pacific. “For the first time, I realized I could have a career in marine biology.” From Harvard, Walter continued his graduate studies in the Joint Program at Massachusetts Institue of Technology (MIT) and the Woods Hole Oceanographic Institution (WHOI). From shrimp to population genetics of brittlestars, Walter found his passion. Today, as a post-doc at WHOI, Walter is heavily involved in the research of the population dynamics of brittlestars throughout the Atlantic and now in the Gulf of Mexico.

As part of the WHOI research team on the Lophelia II cruise, Walter is involved in looking at:
Close up of brittlestar Asteroschema sp. on the coral Callogorgia on the seafloor.

Close up of brittlestar Asteroschema sp. on the coral Callogorgia on the seafloor. Click image for larger view and image credit.


Brittlestar Asteroschema sp. on the coral Callogorgia on the seafloor.

Brittlestar Asteroschema sp. on the coral Callogorgia on the seafloor. Click image for larger view and image credit.


 

There are over 2000 species of brittlestars around the world. Some associate with only one type or species of coral, while other brittlestars may associate with several different species of coral, still others have evolved to simply live on substrates without any connection to corals. Walter’s doctoral research focused on seamounts in the North Atlantic, where he was able to study large communities of brittlestars and their symbiotic relationships with coral.

On this cruise Walter has been able to partner his research with another scientist, Andrea Quattrini of Temple University; Andrea is studying the diversity of various corals observed during their underwater research and the population genetics of Callogorgia, a coral associated with a specific brittlestar. Their combined studies will enhance our understanding of the population structure and connectivity of communities of corals and their associated animals in the Gulf of Mexico.

A constellation of brittestars on the seafloor (538 meters).

A “constellation“of brittestars on the seafloor (538 meters). Click image for larger view and image credit.


Close up of Walter Cho examining a brittlestar in the lab.

Close up of Walter Cho examining a brittlestar in the lab. Click image for larger view and image credit.


When asked if the research team were finding lots of brittlestars in the Gulf of Mexico, Walter answered, “We are seeing about a dozen different species and most of those are associated with corals.” During this cruise, one of the main focus species has been Asteroschema sp., which live on the coral Callogoria sp. However, during yesterday’s dive, a large constellation of brittlestars sat off the shipwreck on the seafloor. Walter went on to explain that the entire ecosystem is connected. If the coral that the brittlestars live on die out, so do the brittlestars, not to mention all the other species that thrive in a specific ecosystem.

Finally we asked Walter to pass on some insight about a career in marine biology. “Pursue what interests you. Work hard at your passion.”

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