by >2 weeks . Changes in flow have led to reduced connectivity in rivers  . Indirect changes include alterations in river morphology, substrate composition, oxygen concentrations and thermal regime in lakes  . Dissolved oxygen concentrations have typically declined and primary productivity has increased with warming. Warming and browning  have occurred in boreal freshwaters, with both positive and negative repercussions on water temperature profiles   and primary productivity  as well as reduced water quality  .
IPCC
Climate Change 2022: Impacts, Adaptation and Vulnerability
IPCC Report