Long-Term Trends in Summertime Habitat Suitability for Delta Smelt, Hypomesus transpacificus

By M. Nobriga, Ted R. Sommer, Kevin Fleming. 2008

88 citations recorded by the source corpus.

The biological productivity of river-dominated estuaries is affected strongly by variation in freshwater inflow, which affects nursery habitat quality. Previous research has shown this is generally true in the upper San Francisco Estuary, California, USA; however, one endemic species of high management importance, delta smelt (Hypomesus transpacificus), has shown ambiguous population responses to river inflow variation. We hypothesized that populationlevel associations with abiotic habitat metrics have not been apparent because the effects occur seasonally, and at spatial scales smaller than the entire upper San Francisco Estuary. We tested this hypothesis by applying regression techniques and principal components analysis (PCA) to a long-term data-set (1970–2004) of summertime fish catch, and concurrently measured water quality (specific conductance, Secchi disk depth, and water temperature). We found that all three water quality variables predicted delta smelt occurrence, and we identified three distinct geographic regions that had similar long-term trends in delta smelt capture probabilities. The primary habitat region was centered on the confluence of

Subfields: Global and Planetary Change, Nature and Landscape Conservation

View Paper: https://www.semanticscholar.org/paper/5554e85ffa053ce4a7946045f3956fdfc73e7a18

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Global and Planetary Change

1. L. Brown
2. Francine H. Mejia
3. Ted R. Sommer
4. J. A. Hobbs
5. J. Durand
6. Peter B. Moyle
7. J. Cech
8. K. Fausch

In Nature and Landscape Conservation

1. L. Brown
2. Francine H. Mejia
3. Ted R. Sommer
4. J. A. Hobbs
5. J. Durand
6. Peter B. Moyle
7. Julian D. Olden
8. Michael P. Marchetti

Citations in the corpus

• A Place to Call Home: A Synthesis of Delta Smelt Habitat in the Upper San Francisco Estuary (2013, background): “Whatever the mechanisms, this change appears to have had a serious effect on habitat quality for delta smelt during both summer (Nobriga et al. 2008) and fall (Feyrer et al.”
• Delta smelt: Life history and decline of a once-abundant species in the San Francisco estuary (2016, background): “Both the TNS (Nobriga et al. 2008) and FMWT (Feyrer et al. 2007) found peak occurrences of Delta Smelt in areas with low specific conductance, with somewhat lower occurrences in fully fresh water.”