Outside Influences

Loss and fragmentation of old-growth forest habitat on a landscape scale..
Loss of the majority of low elevation old-growth forest habitat near marine waters to development and other uses such as timber production was likely the primary cause of the initial marbled murrelet population declines in Washington.

Marine alterations.
Lower numbers of fish caused by overfishing, pollution, and marine habitat alterations also likely contributed to murrelet population declines. In the future, climate change may contribute to lower prey fish populations, which could also affect the murrelets.