|"Devil" pathogens that infect coral|
In a new paper, Miriam and her colleagues studied hundreds or organisms gathered on the 2009 cruise. They counted organisms from 95 different taxa and 11 phyla (some great vocab for science students!). The scariest by far is not a scaly sea monster with pointed teeth, but a single-celled ciliate called Halofolliculina. "about the size of a sesame seed with teeny tiny devil horns. (They are actually pericytostomial wings, not devil horns, but I won’t tell if you don’t.) My collaborators Hank Carson and Marcus Eriksen found these little buggers living on plastic debris floating way offshore in the western Pacific, which wouldn’t be terrifying in itself since a lot of strange critters live on plastic debris But Halofolliculina is a pathogen that causes skeletal eroding band disease in corals, and this piece of debris was headed towards Hawaii." Skeletal eroding band (SEB) disease damages the coral's outer tissue and exposes the fragile skeleton. It has been reported in 82 species of corals according to the Global Coral Disease Database.
|Goniastrea edwardsi with a small focal lesion caused by|
the ciliate Halofolliculina corallasia, which is eroding
the tissue and skeleton. The black specks are
embedded loricae or tests of the ciliate.Photo: Andrew Bruckner
[From Global Coral Disease Database]
There is no direct evidence to indicate that plastic brought skeletal eroding band disease to Hawaii, but it remains a possibility. Equally unsettling is our lack of information on how the various hitchhiking organisms affect the open ocean. As I say in Plastic, Ahoy!, "Miriam wondered if these hitchhikers could change the food chain--the who eats whom--in the gyre. Zooplankton are a critical link in the food chain. But they are not naturally plentiful in the gyre. What would happen if there were not enough to go around?"