Decomposition of senescent blades of the seagrass Halodule wrightii in a subtropical lagoon

Abstract

Senescent blades from the seagrass Halodule wrightii Aschers were suspended in the water column of Laguna Madre (Texas, USA) for a period of 419 d. The initial stage of decomposition was characterized by a rapid loss of organic matter (36% in 24 d) attributed to leaching. Overall, the distribution of polymeric constituents (cellulose, hemicellulose, lignin and cutin) was similar in freshly senescent and highly degraded tissues suggesting that the compounds which comprise the ultrastructure of H. wrightii are degraded at similar rates. Photobleached H. wrightii blades were characterized by a much higher neutral sugar content, similar levels of cutin acids and a nearly complete absence of phenols compared to freshly senescent tissue. -from Authors