Effect of benthic boundary layer transport on the productivity of Mono Lake, California

Louise C Bruce¹ , Robert Jellison² , Jörg Imberger¹ and John M Melack³

¹Centre for Water Research, University of Western Australia, 35 Stirling Highway, Crawley, Western Australia, 6009, Australia

²Marine Science Institute, University of California, Santa Barbara, California, 93106-6150, USA

³Bren School of Environmental Science and Management, and Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, California, 93106-9610, USA

author email corresponding author email

Saline Systems 2008, 4:11doi:10.1186/1746-1448-4-11


Published:	19 August 2008

Abstract

The significance of the transport of nutrient-rich hypolimnetic water via the benthic boundary layer (BBL) to the productivity of Mono Lake was studied using a coupled hydrodynamic and ecological model validated against field data. The coupled model enabled us to differentiate between the role of biotic components and hydrodynamic forcing on the internal recycling of nutrients necessary to sustain primary productivity. A 4-year period (1991–1994) was simulated in which recycled nutrients from zooplankton excretion and bacterially-mediated mineralization exceeded sediment fluxes as the dominant source for primary productivity. Model outputs indicated that BBL transport was responsible for a 53% increase in the flux of hypolimnetic ammonium to the photic zone during stratification with an increase in primary production of 6% and secondary production of 5%. Although the estimated impact of BBL transport on the productivity of Mono Lake was not large, significant nutrient fluxes were simulated during periods when BBL transport was most active.