Date of Award

8-2011

Document Type

Campus Access Thesis

Degree Name

Master of Science (MS)

Department

Environmental Sciences

First Advisor

Juanita Urban-Rich

Second Advisor

Michael Shiaris

Third Advisor

Bob Chen

Abstract

Seawater is abundant with transparent exopolymeric particles (TEP) and Coomassie-stained particles (CSP), often released by diatoms, bacteria, and dinoflagellates. These extracellular polymeric substances (EPS) have important effects on the microbial community, sedimentation, and nutrient cycling. The moon jelly, Aurelia aurita, is known to release mucus containing dissolved organic material, and this study shows that it also releases colloidal particles such as TEP and CSP. To test whether the size of the TEP and CSP released is dependent upon the size of A. aurita individuals, the A. aurita were divided into size categories and left to incubate for 24 hours. Water samples from each A. aurita were filtered and stained for TEP and CSP. A positive relationship between size of the A. aurita and size and abundance of the particles was determined. The results suggest that as A. aurita blooms develop and peak, a substantial supply of colloidal particles are made available to marine food webs, potentially providing large inputs into local carbon cycles and having implications for eutrophication. A. aurita also produces material in particulate form, releasing "blobs" of mucus that can be stained with Coomassie Brilliant Blue (CBB). Mean sinking rates of 146 m d-1 revealed that these blobs are dense, and the high C:N ratios suggest that the blobs are not simply tissue sloughed off the body of A. aurita, which has a C:N ratio of ~4.5 (Pitt et al 2009). During bloom conditions, A. aurita could produce up to 37 mg C m-3 d-1 via production of mucus blobs. This substantial amount of quickly-sinking carbon has the potential to blanket the benthos in coastal areas, providing a large source of food, a mode of transportation for trace metals, and possible impacts on rates of carbon sedimentation and burial in coastal areas.

Comments

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