MARINE BACTERIA OF CARDIGAN BAY. II. BACTERIA IN ROCK POOLS

SUMMARY: Two pools of different characteristics were examined for bacterial content, marine and alien. Comparative monthly counts showed little consistency over the sampling periods and no definite seasonal variation. Temperature, pH and light had little direct influence. Chromogenic strains were few. Most marine bacteria were small Gram-negative rods; a high proportion liquefied gelatin, but other biochemical reactions were weak.
The amount of dissolved oxygen increased with exposure of the pools but decreased in a third pool devoid of visible flora and fauna. All three pools showed a marked increase in marine bacterial content during intertidal exposure. The coli-aerogenes organisms content was low and, as in the case of soil and fresh water, the strains showed no definite seasonal variation.