In 1983, Bob Aller published a seminal paper titled "The importance of the diffusive permeability of animal burrow linings in determining marine sediment chemistry" (Journal of Marine Research, 41: 299-322). He demonstrated that the way inorganic solutes behave when encountering burrow linings is dictated by their charge. Between then and now, two of his graduate students, Shannon Dunn and myself, investigated additional aspects of such biogenic materials' impact on diffusion, including the effects of size on organic solute diffusion and comparisons between pedal mucus of gastropods and burrow linings. My Master's Thesis was completed after two years (summer of 1999 to summer of 2001) in his lab at the Marine Sciences Research Center of Stony Brook University (then SUNY Stony Brook). Diffusion investigations constituted only the second half while the first half explored composition of the mucus of a naticid gastropod (Neverita duplicata) and its decomposition by sedimentary microbial assemblages. Below, you can find copies of my thesis as well as links to publications and presentations that emerged from it. The definitive work, naturally, is the publications in peer-reviewed journals. Work on diffusion is currently in press in the Journal of Marine Research, while another manuscript is prepared on the composition and decomposition studies.
Hannides, A.K., Dunn, S.M., and R.C. Aller (2005) Diffusion of organic and inorganic solutes through macrofaunal mucus secretions and tube linings in marine sediments. Journal of Marine Research, 63: 957-981. [ reprint ]
Hannides, A.K. (2001) The Impact of Biogenic Organic Matrices on Early Diagenetic Processes in Marine Sediments. M.S. Thesis. State University of New York at Stony Brook, New York, U.S.A.
Thesis Committee:
Abstract:
Biogenic organic matrices are common components of various marine regimes, especially sediments, and may significantly alter transport and reaction processes. This Thesis explores the impact of two types of biogenic organic matrices: mucous secretions and organic tube linings.
Mucous secretions of the naticid gastropod Polinices duplicatus are mostly water, have a high inorganic component, and owe their special character to a carbohydrate-protein complex. The pedal mucus' viscous and lubricatory nature is explained by the presence of a sulfur-rich, highly charged macromolecular complex, whereas the additional need for consolidation and compaction of debris in the case of hypobranchial mucus is apparently satisfied by a slightly higher protein content relative to pedal mucus. When exposed to natural microbial assemblages, it decomposes steadily, with the protein moiety being selectively decomposed first.
The gel-like, viscous mucus of P. duplicatus inhibits the diffusion of inorganic and organic solutes. The inhibitory effect is on average more pronounced with the fibrous burrow lining of the ampharetid polychaete Melinna cristata. This difference suggests a structural semi-permeability effect on DOC diffusivity. A charge effect on diffusion has not been observed here, thus contradicting previous reports. However, size-dependent inhibition of diffusion is demonstrated. Inhibition increases with increasing size, but no threshold "filtering" effect was found up to the investigated size of MW 70,000. Organic solute diffusion is enhanced in seawater relative to patterns predicted by relationships derived from distilled water diffusion experiments, due to changes in the conformation of organic macromolecules in electrolyte solutions.
Files for download:
Hannides, A.K. (2001) The Impact of Biogenic Organic Matrices on Early Diagenetic Processes in Marine Sediments. Master's Thesis presentation, Marine Sciences Research Center, SUNY at Stony Brook, June 7th 2001. [ talk slides handout ]
Hannides, A.K. and Aller, R.C. (2001) Impact of Mucopolysaccharide Matrices on Diffusion of Dissolved Substances in Marine Sediments. ASLO Aquatic Sciences Meeting 2001, Albuquerque, New Mexico, February 12th-16th 2001. [ abstract ] [ talk html ] [talk pdf ]
Angelos K. Hannides, Department of Oceanography
Last modified: October 2005