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Endangered Delta Smelt Show Improvement in 2011
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After a decade of declining Delta smelt abundance, the results of the Fall Midwater Trawl Survey (FMWT) conducted by the California Department of Fish & Game (CDFG) indicate that the population might finally be showing signs of improvement. In 1993 Delta smelt were first listed as threatened under the California and Federal Endangered Species acts (ESA) and then in 2010, after further decline, were changed to endangered. Population estimates for Delta smelt have been derived from the FMWT abundance index since 1967, and for the last 10 years the index had been far below the average. So when the index bounced back up to 343 last fall, it caused a bit of a stir (Figure 1).
When discussing Delta smelt, one of the first questions we usually get is, "what are Delta smelt and why are we so concerned with protecting them?" The finger-sized fish were once one of the Delta's most abundant fish species but, due to a short lifecycle of approximately one year, they are extremely susceptible to a changing environment. During spawning season, the Delta smelt migrate up river from Suisun Bay to spawn in sloughs and shallow channels in the upper Delta. After the eggs hatch and the larvae develop swim bladders, they are washed downstream to the salinity-mixing zone. In the next several months, the Delta smelt will grow to around 3 inches before returning to the spawning reach and completing their lifecycle. Since they are so vulnerable they are considered to be a key indicator species in the Sacramento-San Joaquin Delta, and their decline has been linked to an overall decline in the health of the estuary. Furthermore, if the Delta smelt became extinct it could create a cascade of effects that would impact other species within the food web, such as Chinook salmon and striped bass.
This increase in abundance of Delta smelt is a positive sign for the estuary's ecosystem. It is important to not only consider how the higher than usual outflow in 2011 may have affected the Delta smelt population and the habitat that it utilizes, but to also recognize that many actions have been taken in recent years to recover the population. A goal of the Sacramento-San Joaquin Delta Native Fishes Recovery Plan is to evaluate and determine how these management decisions have benefitted the Delta smelt population.
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IN THE NEWS: Recent stories you might have missed...
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Salmon rebound in Sacramento Valley
Sacramento Bee
 The salmon came back. After four long years of record-low numbers, the fall-run chinook salmon population surged back from the ocean this year, once again filling the Sacramento Valley's rivers on their spawning run. Hatcheries on the American River, the Feather River and Battle Creek - the region's three largest - saw the return of more than double the number of fish in 2010, and five times as many as in 2009... Read more >
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California's Delta Ecosystem Is Healthier, For Now
New York Times
The ecosystem of the delta where the Sacramento and San Joaquin rivers meet has been in the legal equivalent of an intensive care unit for four years. But just before Christmas, an upbeat report came in, showing that a year of copious rain and snow had significantly improved.the delta's condition. High flows of water from the melting of deep snow in the Sierra provided enough for both the tiny fish known as the delta smelt, long considered on the brink of extinction, and for the farming communities that have chafed under legal rulings... Read more >
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Project aims to show crops, marshland can coexist
San Francisco Chronicle
Five acres of mud and rice stubble doesn't look much like fish habitat, but the rectangular patch of summertime cropland is in the process of being converted to a teeming marsh filled with young salmon.
The conversion to wetland of the rice paddy at Knaggs Ranch, north of Woodland next to the Yolo Bypass, is an experiment that conservationists hope will eventually lead to the restoration of ancient floodplains all along the Sacramento and San Joaquin River corridors... Read more >
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Marine Invasive Species Report Identifies New Threats
Fish & Game News
Four new non-native aquatic species have taken up residence in San Francisco Bay, according to a new report published by the Department of Fish and Game (DFG). The 2011 Invasive Species Report includes the first records of the appearance in the San Francisco Bay of four species previously found only in other parts of the coast. These organisms include:
* Caprella simia, a Caprellid, or "skeleton" shrimp, which was first discovered in California's Long Beach Harbor in 2000... Read more >
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New No Fishing Zones for California
Santa Barbara Independent
Love it or hate it, the waters of Southern California just became a whole lot more conservation-friendly. After more than four years of meetings, votes, controversy, and public pleas both for and against the idea, January 1, 2012 marked the official roll-out date for 36 brand new state-sanctioned marine protected areas (MPAs) dotting the Pacific Ocean between Point Conception and the Mexico border... Read more >
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Sierra snow survey finds hardly any
San Francisco Chronicle
It was supposed to be an icy traverse through a blanket of white, but the first Sierra snow survey of the year on Tuesday was more of a leisurely stroll through a sun-dappled meadow. There was about as much snow on the ground last July 4 as there is now at historic Phillips Station off Highway 50 near the Sierra at Tahoe resort. Some say the skiing was better then, too. Frank Gehrke, chief snow surveyor for the California Department of Water Resources, might have had better luck counting butterflies than taking snow measurements... Read more >
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