Kids' Species Information

Delta Smelt

Girls fishing
Girls Fishing, USFWS Photo

STATUS: Threatened. This means that we are worried about the species but that it is not about to go extinct right now. However, during the last few years the number of Delta smelt has declined steeply. We have now decided that we should change the species to endangered.

DESCRIPTION: Delta smelt are slender fish. They are about 5.0 to 7.0 cm long. (About 2 to 3 inches) Delta smelt have a steely blue sheen on the sides. They almost seem translucent. They live together in groups called schools. Most live only one year.

FOOD: Small aquatic animals, especially tiny shrimp-like animals called copepods.

Delta smelt life stages
Delta smelt life stages, RenĂ© Reyes, USBR 

HABITAT: Delta smelts can tolerate a wide range of saltiness in the water. But they spend most of their time in water with 2 parts salt to 1000 parts water. See pictures of the delta.

MATING: Delta smelts spawn in shallow, fresh or slightly brackish water. They swim upstream from where they usually hang out. Spawning happens in the spring.

PREDATORS: Larger fishes. The non-native striped bass and largemouth bass are threats to the Delta smelt.

American Indians once caught Delta smelt for food. Now days people do not fish for them. But things we do to protect the smelt will help other fish that people do catch.

RANGE: Delta smelt are found only from the Suisun Bay upstream through the Sacramento/San Joaquin River Delta. Look at a map of California rivers (PDF 30 KB). Do you see where most of them meet? That is where the delta smelt live.

THREATS: Reduced water flow. Smelt getting trapped in water pumps and power plant intakes. Changes in food supply. Water contamination. Increased salinity ("saltiness"). Competition and predation from non-native species.

What You Can Do

Don't waste water. Be careful what you pour down sinks. Remember that it will end up in your community's water. Do not release exotic fish into streams. Find out why. See What You Can Do to Help Wildlife and Plants (PDF 199 KB) for more ideas.

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