Differential fates of Emiliania huxleyi-derived fatty acids and alkenones in coastal marine sediments: Effects of the benthic crustacean Palaemonetes pugio

Authors: Ding, Haibing; Sun, Ming-Yi

Source: Journal of Marine Research, Volume 64, Number 5, September 2006 , pp. 759-781(23)

Publisher: Sears Foundation for Marine Research

Abstract:

In order to examine how benthic crustaceans affect the fates of phytoplankton-derived lipid biomarkers (fatty acids and alkenones) in coastal marine sediments, we incubated Emiliania huxleyi cells in microcosms (pre-sieved sediment cores with and without the grass shrimp Palaemonetes pugio ) over six weeks. Crustacean, transport of surface sediments, and distributions of algal lipids were followed during incubations. Crustacean activities enhanced degradation of algal fatty acids (2-4× faster) but had a small impact on algal alkenone degradation (<1.4×) compared to the controls. During the first few days of incubations, alkenone concentrations were enriched while algal fatty acid concentrations were depleted in suspended particles in the overlying water of cores, indicating that P. pugio selectively grazed algal material from sediments and preferentially assimilated fatty acids over alkenones through digestion. Unlike algal fatty acids, alkenones were degraded primarily by microbial processes rather than by crustacean grazing. A substantial fraction (20-30%) of algal lipids was moved downward to the subsurface of sediments by P. pugio but algal fatty acids were more rapidly (3-6×) degraded than alkenones. In the presence of P. pugio, fatty acids bound in cell membrane and intracellular storage components degraded similarly, indicating that the crustacean activities minimized the effects of structural associations on fatty acid decomposition. Furthermore, there was no preferential degradation of 37:3 and 37:2 alkenones in both crustacean and control cores, suggesting that the U₃₇^k' index (a paleotemperature indicator) was not significantly altered by P. pugio's grazing or microbial decomposition.

References: 61 references open in new window

Articles that cite this article?

Document Type: Research article

DOI: http://dx.doi.org/10.1357/002224006779367230

Publication date: 2006-09-01

More about this publication?

• Editorial Board
• Information for Authors
• Subscribe to this Title
• ingentaconnect is not responsible for the content or availability of external websites

Related content

• In this: publication
• By this: publisher
• In this Subject: Oceanography
• By this author: Ding, Haibing ;  Sun, Ming-Yi

Website © Publishing Technology. Article copyright remains with the publisher, society or author(s) as specified within the article.

• Terms and conditions
• Privacy policy
• Information for advertisers