Subsurface Chlorophyll Maximum and Associated Cyclotella Pulse in Lake Superior
✍ Scribed by Gary L. Fahnenstiel; Janice Glime
- Book ID
- 102870988
- Publisher
- John Wiley and Sons
- Year
- 1983
- Tongue
- English
- Weight
- 694 KB
- Volume
- 68
- Category
- Article
- ISSN
- 1434-2944
No coin nor oath required. For personal study only.
✦ Synopsis
An investigation of the subsurface chlorophyll layer (SCL) in Lake Superior was conductedfrom 1 May through 15 October. During spring unstratified conditions (1 May-17 July), chlorophyll a and phytoplankton biomass were vertically and temporally uniform. Phytoflagellates such as Rhodomonas minuta, Cryptomonas spp., and Ochromonas spp. were dominant at this time. The photosynthetic maximum was associated with the depth receiving 10 o/o of surface irradiance, ca. 15-25 m. Once thermal stratification occurred, a SCL developed around 20 m. Although epilimnetic chlorophyll concentrations remained similar to spring mixing levels, concentrations in the SCL increased 3-fold. I n situ production was the prir.cipal process associated with the development of the SCL. The upper portion of the SCL was dominated by Cyclotella species; C . stelligera, C. comensis, and C . ocellata. The increased abundance of Cyclotella appeared to be related t o stable irradiance fields produced during thermal stratification.