Tolerance Limit

The biological expression of an organism to live within certain prescribed physical, chemical, and biological parameters. For aquatic organisms living in cold, highly oxygenated water, the limits for life are defined by the amounts of dissolved oxygen, fluctuations in ambient temperature, and a variety of other related conditions that, taken together characterize the world’s trout rivers. Exceeding a tolerance limit for any one factor effectively eliminates all organisms from that zone that share that characteristic.

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