Delta Smelt
Hypomesus
transpacificus
Endangered Status
The Delta Smelt is on the U.S.
Endangered Species List. It is classified as threatened throughout
its range in California, where it occurs only in Suisin Bay and the
Delta in San Francisco Bay, at the mouths of the San Joaquin and
Sacramento Rivers. This once-abundant fish is said to have declined
by 90 percent since the 1970s. Its decline can be attributed to the
draining of water from the two rivers for agricultural and
residential use. This has lowered the water level in the smelt’s
habitat, altering the ecosystem and the natural balances within it.
Pollution and the introduction of non-native species that compete
for food and habitat has contributed to this fish’s diminished
numbers.
