Save the Delta Smelt!

The Delta Smelt is an endangered fish species that lives in the Sacramento Delta. This species' survival is in danger, due to factors ranging from food supply limitations to environmental challenges. The researchers care about the Delta Smelt population in the Delta because it is seen as an indicator fish for the Sacramento Delta's health.

One of the reasons that the Smelt is dying is the lack of food. The Smelt eats the zooplankton, which in turn eats the phytoplankton. If the phytoplankton dies out, then all of the Delta fish, including the Smelt would go extinct.

Dr Ted Sommer is a government scientist who studies the effect of phytoplankton on Delta Smelt. He informed us during the phone interview that he measures phytoplankton in water via probes, takes water samples, and looks at it through microscopes. The process takes about two weeks.

Our FLL team is devising a color sensor to sense the Chlorophyl in the water. We believe that Chlorophyl might help indicate the level of phytoplankton in the water.

The other reason that impacts the Delta Smelt is the fact that water is getting clearer, warmer and contaminated. There are also too much weeds.

Dr Ted Sommer also informed us that there are Federal laws that would put protections for the Smelt, such as restricting water division, limiting flow requirement, and habitats restoration.

We visited Dr Tien-Chieh Hung, a researcher at UC Davis Fish Conservation and Culture Lab. He leads the effort to raise a refuge population of Delta Smelt since 2007. This is a breeding and hatching plan that minimizes deviation from the wild population and maximizes genetic diversity. The scientists genetically screen and choose fish from 300 different families of smelt in the refuge for breeding, as well as introduce 100 new fish from the wild each year to the gene pool. The breeding is carefully monitored by researchers around the clock to assure success. The season of reproduction which goes from March to May is critical for this activity.

The scientists merge the eggs in the egg cups, then put them in incubation tubes. Once the Smelt has hatched, they are transferred to tanks. Young Delta Smelt is not harmed by light, whereas the older ones are very light sensitive. Once the Smelt is too big for those tanks, they are transferred to another tank. The process repeats until the Smelt has reached their full size. The Delta smelt is tagged for progress monitoring. It only takes them 5 seconds to tag one fish.

The UC Davis Fish Conservation and Culture Lab also focuses on research on basic biology of smelts. They raise separate populations of fish for scientific studies, including aquaculture engineering, reproduction and marking and even how to extend the delta smelt's life span. The lab currently hosts fish that has been living as long as three times the normal lifespan of the species. These fish are never meant to be introduced to the wild, but they are a great help for researchers to analyze impacts of different solutions without risking the wild population.

If the Delta Smelt goes extinct, not much will change in the Delta, because there are a lot of other fish that will take their place. But the fate of the Smelt indicates the health of the delta. The other fish that are facing the similar problem are pelagic fish, such as the Striped Bass, Long Fin Smelt, and ThreadFin Shad. Their populations have not recovered since 1967. The effort of human intervention dates back to 1992. To help save the Delta, we need to act fast. We need to continue the breeding refuge population and study the environmental effects to propose the best solution to bring back the Delta Smelt population. Our team’s proposed sensor aligns with the environmental efforts.

Photo Gallery

  • Dr Hung at UC Davis Fish Conservation and Culture Lab.

  • Three labs shown here: egg and live prey, larval, and Adult.

  • Tanks of fish inside an adult lab.

  • The feeding of adult Smelt in a tank.