Premium
Big Soda Lake (Nevada). 4. Vertical fluxes of particulate matter: Seasonality and variations across the chemocline
Author(s) -
Cloern James E.,
Cole Brian E.,
Wienke Sally M.
Publication year - 1987
Publication title -
limnology and oceanography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.7
H-Index - 197
eISSN - 1939-5590
pISSN - 0024-3590
DOI - 10.4319/lo.1987.32.4.0815
Subject(s) - chemocline , particulates , seasonality , environmental science , oceanography , bloom , photic zone , seston , pycnocline , diatom , productivity , water column , phytoplankton , geology , ecology , nutrient , biology , macroeconomics , economics
Vertical fluxes of particulate organic matter were measured with sediment traps above and below the chemocline of Big Soda Lake to define the seasonality of sinking losses from the mixolimnion and determine the effectiveness of the chemocline (pycnocline) as a barrier to the sinking of biogenic particles. Seasonality of sedimentation rates reflected seasonal changes in the community of autotrophs. During summer‐autumn, when production is dominated by autotrophic bacteria, vertical fluxes were small: 100 mg C m −2 d −1 and ≅0.5 mg Chl a m −2 d −1 . Following the winter diatom bloom, vertical fluxes increased markedly: ≅570 mg C m −2 d −1 and 23 mg Chl a m −2 d −1 . The bulk of the seston (> 80%) and particulate carbon (≅ 65%) sinking to the chemocline passed through it, showing that this very sharp density discontinuity does not effectively retard the sinking of particulate matter. However sinking losses of particulate carbon were generally small (≅10%) relative to previous measures of primary productivity, indicating that the mixolimnion is a zone of efficient carbon cycling. Exceptions occurred following the winter bloom when sinking losses were a larger fraction (≅40%) of productivity.