Low-density particles as potential nitrogenous foods for benthos

Lawrence M. Mayer, Peter A. Jumars, Gary L. Taghon, Stephen A. Macko, Susan Trumbore
1993 Journal of Marine Research  
The demonstrated bias of both macrobenthos and fluids to mobilize low-density particles leads to their potential importance as nutritional materials in benthic systems. We fractionated sediments from three coastal regions into low-and high-density separates, and examined both their organic geochemical characteristics and effects on ingestion rates of a deposit feeder. The low-density separates were highly enriched in total organic matter relative to the high-density phases. Enzymatically
more » ... zable protein concentrations in low-density separates were as much as 57fold higher than the corresponding high-density separates, though some samples from Puget Sound and the Mediterranean Sea showed no enrichment at all. Low-density phases without nutritional enrichments were usually composed of woody debris. In spite of the organic richness of the low-density phase, it makes up no more than a minor fraction of either total sedimentary organic matter or its nutritional component. Addition of anomalously high concentrations of lowdensity materials to sediments caused a deposit-feeding spionid polychaete to reduce ingestion rates. ABSTRACT The demonstrated bias of both macrobenthos and fluids to mobilize low-density particles leads to their potential importance as nutritional materials in benthic systems. We fractionated sediments from three coastal regions into low-and high-density separates, and examined both their organic geochemical characteristics and effects on ingestion rates of a deposit feeder. The low-density separates were highly enriched in total organic matter relative to the high-density phases. Enzymatically hydrolyzable protein concentrations in low-density separates were as much as 57-fold higher than the corresponding high-density separates, though some samples from Puget Sound and the Mediterranean Sea showed no enrichment at all. Low-density phases without nutritional enrichments were usually composed of woody debris. In spite of the organic richness of the low-density phase, it makes up no more than a minor fraction of either total sedimentary organic matter or its nutritional component. Addition of anomalously high concentrations of low-density materials to sediments caused a depositfeeding spionid polychaete to reduce ingestion rates.
doi:10.1357/0022240933223738 fatcat:z6vbbef4qzb3hapwtsgbprkb3u