Transparent exopolymer particle (TEP) production under CO2 enrichment: a mesocosm experiment

Abstract

Transparent exopolymer particles (TEP) are abiotically formed aggregates within the water column from physiological stress causing polysaccharides to be exuded by phytoplankton and some bacteria. They are considered a possible mechanism for carbon export from surface waters due to their high stickiness and thus ability to cause large aggregates to form. Ocean acidification is a process which may greatly influence the production and cycling of TEP within the water column. The San Juan Islands experience both anthropogenic and natural acidification of their surrounding waters. The influence of ocean acidification on TEP production within Friday Harbor waters has not yet been studied. To study TEP production under ocean acidification nine mesocosms with three treatments were utilized. Though no difference between the control and high treatments were found, possible evidence was seen for CO2 effecting TEP production; The drift treatment was significant different from the maintained high and control treatments, suggesting repetitive addition of CO2 to the environment does have an effect on TEP production within the mesocosms.