Abstract
Sedimentation rates were determined for various diatom species, and both average and maximum sinking velocities of sedimenting diatoms were calculated during a spring bloom investigation in the central Baltic Sea in 1986. Up to 25 and 50% of theChaetoceros spp. andThalassiosira levanderi populations, respectively, sedimented daily. Daily sedimentation rates of other diatoms, dinoflagellates andMesodinium rubrum, however, were less than 1% of their respective standing stocks. TheT. levanderi population was divided into two subpopulations: while one was sinking, the second was actively dividing (recognizable by paired-cell stages) with a specific growth rate of >0.2 to 0.3 d−1. These paired cells were never found in sediment trap samples. The average sinking velocity ofChaetoceros spp. was 15 to 30 m d−1; that ofT. levanderi was higher. The maximum sinking velocity of cells was at least 70 m d−1. According to these observations, the formation of aggregates (which enhances sinking velocity), and their sedimentation, represent a highly selective process. This indicates that diatom aggregates do not act as roving filters, sweeping the water clear while sinking.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.