Impacts of water depth, sediment pigment concentration, and benthic macrofaunal biomass on sediment oxygen demand in the western Arctic Ocean

• Published in: Canadian journal of fisheries and aquatic sciences 2005-08, Vol.62 (8), p.1756-1765
• Main Authors: Clough, Lisa M, Renaud, Paul E, Ambrose Jr, William G
• Format: Article
• Language: English
• Subjects: Animal, plant and microbial ecology; Applied ecology; Biological and medical sciences; Biomass; Canyons; Carbon cycle; Deep water; Exploitation and management of natural biological resources (hunting, fishing and exploited populations survey, etc.); Fundamental and applied biological sciences. Psychology; Macrofauna; Marine; Marine ecology; Oxygen; Oxygen demand; Pigments; Respiration; Sediments; Shallow water; Spatial analysis; Standard deviation; Water depth
• ISSN: 0706-652X; 1205-7533
• DOI: 10.1139/f05-102

We investigated the impacts of water depth, sediment pigment concentration, and benthic macrofaunal biomass on sediment oxygen demand (SOD) during three cruises to the western Arctic Ocean. SOD values were similar to those of most studies from the Arctic and ranged from a high of 20.68 mmol O 2 ·m –2 ·day –1 at a shallow shelf station to a low of 0.29 mmol O 2 ·m –2 ·day –1 at the deepest basin station (3648 m). SOD was significantly greater at shallow sites (500 m; mean = 1.39 mmol O 2 ·m –2 ·day –1 ; SD = ±0.96). As hypothesized, SOD was negatively correlated with water depth and positively correlated with both surface-sediment pigment concentration and macrofaunal biomass, with macrofaunal biomass explaining approximately 74% of the variability in SOD. We propose that higher macrofauna-normalized respiration rates (i.e., SOD divided by macrofaunal biomass) in deep water indicate that microbial–meiofaunal respiration predominates in deep versus shallow water. Finally, deeper stations associated with Barrow Canyon had SODs, benthic macrofaunal biomass, and surface-sediment pigment concentrations that were similar to those of shallower shelf locations, suggesting down-canyon transport of organic material.