Characteristics of bacterial communities in the Gulf of Alaska.

Taxonomic diversity, physiological tolerance ranges, and nutrient utilization capabilities were determined for bacterial communities in Gulf of Alaska surface waters and sediments. Taxonomic diversity was assessed using Shannon Weaver (H') and equitability (J') indices. Physiological tolerance and nutritional versatility indices were developed to further assess the state of "informational heterogeneity" within the bacterial communities. The Gulf of Alaska bacterial communities were characteristically diverse; the bacterial populations in these marine ecosystems generally were eurytolerant and nutritionally versatile. The maintenance of a high degree of informational heterogeneity was found to be characteristic of these bacterial communities. It appears to be of adaptive advantage to maintain diverse populations with physiological tolerances whose ranges exceed those experienced within the natural habitat, and for the bacterial communities to possess a high degree of nutritional versatility within these marine ecosystems.