Thermal stress in Thalassia tetudinum

Thesis/Dissertation · Wed Oct 01 04:00:00 EDT 1975

OSTI ID:4054586

Schroeder, P B

A study of the effect of a thermal effluent on Thalassia testudinum was made at Guayanilla Bay, Puerto Rico, and at the laboratory of the Puerto Rico Nuclear Center at Mayaguez, Puerto Rico. Biomass of Thalassia was inversely correlated with temperature in established turtle grass flats near a thermal plume. Visual signs of stress were noted in transplanted Thalassia samples after two weeks of exposure to temperatures of 34.5$sup 0$ to 35$sup 0$C. Mortality occurred in transplanted Thalassia after seven weeks of exposure to 35.0$sup 0$ to 36.4$sup 0$C. Biomass and pigment values varied nonlinearly with temperature. There was strong correlation between the effect of temperature on biomass and on the absorption ratio 410 nm/665 nm of acetone extracts of leaf material between 28$sup 0$ and 36$sup 0$C. This absorption ratio was proposed as an index of thermal stress in the plant. Radionuclide uptake experiments demonstrated that osmoregulation in Thalassia was affected by temperature. Sodium and certain other cations were preferentially excluded from Thalassia at temperatures normally experienced by the plant. Between 32$sup 0$ and 34.5$sup 0$C accelerated uptake of these cations in leaves occurred. Sodium poisoning and breakdown of osmoregulatory processes were proposed as the cause of visual signs of thermal stress and mortality in Thalassia. (auth)

• Research Organization: Miami Univ., Coral Gables, Fla. (USA)
• NSA Number: NSA-33-023319
• OSTI ID: 4054586
• Report Number(s): TID--26952
• Country of Publication: United States
• Language: English

Related Subjects

*BIOMASS-- TEMPERATURE DEPENDENCE
*GRASS-- MORTALITY
*RADIOISOTOPES- - UPTAKE
*SODIUM-- TOXICITY
*THERMAL EFFLUENTS-- ENVIRONMENTAL EFFECTS
*THERMAL STRESSES-- ENVIRONMENTAL EFFECTS
520400* --Environmental Sciences
Aquatic--Thermal Effluents Monitoring & Transport
AI L-77 REACTOR
N44630* --Environmental & Earth Sciences--Thermal Effluents-- Water
PUERTO RICO NUCLEAR CENTER