The
Issue
Recent
increases in the number of Caspian Terns nesting in the Columbia River
estuary has led to concerns over their potential impact on the recovery
of threatened and endangered salmon and steelhead (salmonids). Caspian
terns have nested in the Columbia River estuary since the mid-1980s,
using habitat created by the deposition of dredge spoils on East Sand
Island and Rice Island. Caspian Tern numbers have increased from an
estimated 1,000 pairs in 1984 to a peak of 10,000 pairs in 2002. This
colony is expected to grow in size because of an expected recruitment
from the high number of fledglings produced from 2001 to 2003.
Federal
and State agencies and non-governmental organizations have agreed
to explore options for restoring, creating, and enhancing nesting
habitat for Caspian terns throughout portions of the Pacific Coast/Western
region (California, Oregon, Washington, Idaho, and Nevada), as one
means to reduce and disperse the large tern colony on East Sand Island
in the Columbia River estuary. The potential benefits of this proposed
action would reduce the level of tern predation on out-migrating young
salmon (smolts) in the Columbia River, and lower the vulnerability
of a significant portion (70%) of breeding Caspian terns in the Pacific
Coast/Western region to stochastic events such as predators, human
disturbance, storm events, or disease.
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