| || || Prakash, Reema|
| || || The stress physiology of Enteromorpha flexuosa (Wulfen) and Enteromorpha intestinalis (Linnaeus) (Chlorophyta) as an indicator of environmental stress in the intertidal zones|
Institution: University of the South Pacific.
Subject: Stress (Physiology), Stress (Psychology), Environmental psychology
Call No.: Pac QP 82 .2 .S8 P73 2008
Copyright:10-20% of this thesis may be copied without the authors written permission
Abstract: Enteromorpha flexuosa and Enteromorpha intestinalis are filamentous green algae that usually grow attached to surfaces in the intertidal zones. Algae are rapid responders to water quality changes, hence considerable information concerning the environmental condition of an aquatic habitat can be obtained from their physiological analyses. This thesis examined the effects of changes on environmental conditions such as temperature, pH, nitrogen levels and presence of herbicide on the physiology of E. flexuosa and E. intestinalis. The possibility of the algae’s physiological conditions to act as a bioindicator of the intertidal environment was investigated. The algae were cultured in the artificial seawater medium under laboratory conditions and exposed to variable temperature, pH, nitrogen (ammonium and nitrate) and herbicide levels. The germling growth rates, photosynthetic rates, total chlorophyll content, total soluble proteins and carbohydrates within the algae were then determined. Similar physiological studies were done on E. flexuosa and E. intestinalis collected from Nasese, Lami and Laucala Beach area around Suva. The results obtained showed that E. flexuosa and E. intestinalis were affected by the variations in their abiotic environment. Increase in temperature and herbicide levels had an adverse effect on algal growth and survival while increase in pH and high nitrogen levels advanced algal growth and survival. The findings indicate that Enteromorpha are quite sensitive to temperature and herbicide. They are a little more tolerant to varying pH. These algae are excellent bio-indicators for high nitrogen levels (especially ammonium) as their presence in the intertidal zone indicates high nitrogen levels.