What is the relationship between water temperature and dissolved oxygen in the water?
In general, the colder the solvent, the greater the solubility of the gas.
And thus, to a first approximation, cold solvents can dissolve much greater volumes of gas than hot solvents. In water, the arctic, and the antarctic oceans (still) teem with marine life, and this is largely because the oxygen content of the polar oceans is greater because of the increased oxygen solubility.
Anyway, check the web for grafix of gas solubility versus temperature.