Relationship between Heat Tolerance and the Vertical Distributtion of Intertidal Algae

Abstract

Heat tolerance of several intertidal and subtidal algae was examined with reference to the rate of photosynthesis and respiration in summer season. The thermal environment of these species was also measured in order to gain insight on the factors controlling the vertical distribution of intertidal algae.
The temperature tolerance of tidal pool algae seemed related to the height of the growing site. Algae growing in high tidal pools tolerated higher temperatures than algae growing in the low tidal pools or in the subtidal zone. Algae which were desiccated at an ebb tide also tolerated higher temperatures. However, these species showed no relationships between height of growing sites and temperature tolerance. It was concluded that tolerance to high temperature play an important role in controlling the vertical distribution of algal flora in the intertidal zone.