| dc.contributor.author | Scarratt, Michael Grant. | en_US |
| dc.date.accessioned | 2014-10-21T12:35:02Z | |
| dc.date.available | 1995 | |
| dc.date.issued | 1995 | en_US |
| dc.identifier.other | AAINN05229 | en_US |
| dc.identifier.uri | http://hdl.handle.net/10222/55044 | |
| dc.description | The cage-culture turbidostat allows phytoplankton to be maintained in a constant chemical environment for extended periods, and growth rate to be easily determined. The use of this system to study growth and toxin content in the marine dinoflagellate Alexandrium tamarense represents a new development in this field, since continuous culturing of toxic dinoflagellates has previously been unsuccessful. The hypothesis that the toxin content of the cells was inversely proportional to their growth rate was investigated. The effects of both irradiance reductions and daylength reductions were tested, as well as the effects of circadian growth cycles. | en_US |
| dc.description | Moderate irradiance reductions which reduced the growth rate were not accompanied by toxin content changes. Large irradiance reductions also produced significant reductions in total toxin per cell. Daylength reduction had no effect on either growth rate or toxin content. Thus the initial hypothesis was rejected and it was concluded that light was essential for toxin synthesis. Irradiance reductions also produced measurable changes in the toxin profile, irrespective of growth rate, suggesting irradiance-dependent differential synthesis of the various toxins. Experiments with phased-dividing cultures showed that both toxin content and toxin profile were diurnally variable. Toxin content was highly correlated with chlorophyll-a, indicating that it is probably a direct function of cell size. Diurnal toxin profile changes were also consistent with irradiance-dependent differential synthesis. | en_US |
| dc.description | Thesis (Ph.D.)--Dalhousie University (Canada), 1995. | en_US |
| dc.language | eng | en_US |
| dc.publisher | Dalhousie University | en_US |
| dc.publisher | | en_US |
| dc.subject | Biology, Ecology. | en_US |
| dc.subject | Health Sciences, Toxicology. | en_US |
| dc.subject | Biology, Microbiology. | en_US |
| dc.subject | Biology, Oceanography. | en_US |
| dc.subject | Environmental Sciences. | en_US |
| dc.title | Influence of light regimen on the growth and toxicity of Alexandrium tamarense. | en_US |
| dc.type | text | en_US |
| dc.contributor.degree | Ph.D. | en_US |
