Factors Affecting the Retention of Eukaryotic Phytoplankton within the Euphotic Zone
| dc.contributor.author | Corbett, Andrea Cathryn | |
| dc.date.accessioned | 2022-06-30T23:35:04Z | |
| dc.date.available | 2022-06-30T23:35:04Z | |
| dc.date.issued | 1979-06 | |
| dc.description | 67 pages | en |
| dc.description.abstract | Phytoplanktonic species face a serious problem in balancing photosynthetic light requirements with nutrient needs. Optimal light intensities are found toward the surface, while nutrients are usually in greater concentrations below the epilimnion. Motile species, such as the flagellates or gas vacuolate blue-green algae, collect at depths which optimize these needs, or migrate vertically to take maximal advantage of each in turn. Phytoplankton, with few exceptions, are denser than their media and without various internal and environmental suspension factors, non-motile species sink irrevocably from the euphotic zone. The subject of phytoplanktonic suspension has been reviewed by Hutchinson (1967), who dealt with limnetic species, and Smayda (1970) , who considered the problem in marine organisms. Research published after these papers appeared has added new dimensions to our understanding of the problem, and has stimulated the writing of this critical review. Since many of the suspension factors recognized are employed by both marine and fresh water species, it is convenient and useful to combine them into one paper. The prokaryotic phytoplankton are not considered here for a current and detailed analysis of gas vacuoles, the floatation bodies of prokaryotes, has been prepared by Walsby (1978). Many factors , both physical and biological, are implicated in maintaining epilimnetic populations of nonmotile phytoplankton. The primary mechanism is wind-induced turbulence. Even fairly light winds create Langmuir spirals which circulate and retain motile and nonmotile cells in an even distribution throughout the upper waters. Non-motile cells are dependent upon turbulence, and normally bloom only when a substantial mixing of nutrients and cells occurs in the euphotic zone. Motile cells lose position al control in turbulence but may become dominant in calm, stratified conditions. The many mechanisms which reduce sinking rate s in still laboratory media become effective in nature only as turbulence decreases. These secondary retention factors include cell size , shape, density, colony formation, mucous secretion, age, selective ion accumulation, fat storage, light, nutrient availability , etc. Each of these mechanisms are discussed and where possible their values to different groups of phytoplankton are compared. | en |
| dc.identifier.uri | https://hdl.handle.net/1794/27213 | |
| dc.language.iso | en | en |
| dc.rights | Creative Commons BY-NC-ND 4.0-US | en |
| dc.subject | Marine Biology | en |
| dc.subject | Phytoplankton | en |
| dc.title | Factors Affecting the Retention of Eukaryotic Phytoplankton within the Euphotic Zone | en |
| dc.type | Thesis / Dissertation | en |