White Sturgeon Spawning in the San Joaquin River, California, and Effects of Water Management

2015 ◽  
Vol 7 (1) ◽  
pp. 171-180 ◽  
Author(s):  
Zachary J. Jackson ◽  
Joshua J. Gruber ◽  
Joel P. Van Eenennaam
Keyword(s):  
Water Management ◽  
San Francisco ◽  
San Francisco Estuary ◽  
Sacramento River ◽  
White Sturgeon ◽  
Late Winter ◽  
Successful Management ◽  
Pulse Flow ◽  
San Joaquin River ◽  
The World

Abstract Inadequate recruitment is a hallmark of declining sturgeon populations throughout the world. Efforts to understand and address the processes that regulate recruitment are of foremost importance for successful management and recovery. Fish biologists previously only knew San Francisco Estuary white sturgeon (Acipenser transmontanus) to spawn in the Sacramento River, California. We assessed potential white sturgeon spawning locations by deploying artificial substrate samplers during late winter and spring of 2011 and 2012 from river kilometers 115.2 to 145.3 of the San Joaquin River. Collections of fertilized eggs, coupled with hydrology data, confirm that white sturgeon spawned within one and four sites in the San Joaquin River during wet (2011; n = 23) and dry (2012; n = 65) water-year conditions. Small pulse flow augmentations intended to benefit juvenile salmonids appear to have triggered white sturgeon spawning within this system. Understanding the effects of water management on spawning and subsequent recruitment is necessary to increase white sturgeon recruitment to the San Francisco Estuary.

scholarly journals Confirmed Observation: A North American Green Sturgeon Acipenser medirostris Recorded in the Stanislaus River, California

2018 ◽  
Vol 9 (2) ◽  
pp. 624-630 ◽  
Author(s):  
Jesse T. Anderson ◽  
Gregg Schumer ◽  
Paul J. Anders ◽  
Kyle Horvath ◽  
Joseph E. Merz
Keyword(s):  
San Francisco ◽  
North American ◽  
San Francisco Estuary ◽  
White Sturgeon ◽  
Green Sturgeon ◽  
Distinct Population ◽  
Acipenser Medirostris ◽  
San Joaquin River ◽  
Distinct Population Segment ◽  
Population Segment

AbstractTwo sturgeon species are native to the San Francisco Estuary watershed in California: White Sturgeon Acipenser transmontanus and North American Green Sturgeon Acipenser medirostris. The San Francisco Estuary has two main tributaries, the Sacramento and San Joaquin rivers. Recent studies have shown that the San Joaquin River is used by Green and White Sturgeon and that at least a small number of White Sturgeon spawn there when environmental conditions allow. However, records of Green Sturgeon in the San Joaquin River and its tributaries are rare and limited to information from angler report cards. In 2006, the National Marine Fisheries Service listed the southern distinct population segment of North American Green Sturgeon as threatened under the Endangered Species Act. Federally designated critical habitat for the southern distinct population segment of Green Sturgeon does not extend upstream of the San Joaquin River's confluence with the Stanislaus River. We recently confirmed an adult Green Sturgeon holding in a deep pool near Knights Ferry, California in the Stanislaus River. We observed and recorded the fish using a GoPro® video camera and used environmental deoxyribonucleic acid sampling techniques to confirm species identification. This paper provides the first confirmed record of Green Sturgeon in any tributary of the San Joaquin River, which is beyond the designated critical habitat area. Future well-designed research focused on the San Joaquin River and its tributaries is expected to improve our understanding regarding the importance of these rivers for the various life stages of North American Green Sturgeon.

scholarly journals Living Fossils: Sturgeon of the San Francisco Estuary

2021 ◽  
Vol 9 ◽  
Author(s):  
Page E. Vick ◽  
John T. Kelly
Keyword(s):  
Climate Change ◽  
Water Management ◽  
San Francisco ◽  
New Technologies ◽  
San Francisco Estuary ◽  
Body Armor ◽  
White Sturgeon ◽  
Spawning Habitat ◽  
Living Fossils ◽  
Sturgeon Species

Sturgeon are fish that are considered living fossils. Their ancestors date back over 200 million years, to the same time as dinosaurs. These fish can grow taller than humans (over 2 m), weigh over 160 kg, and live as long as humans. Sturgeon species have special adaptations, such as a vacuum-like mouth and body armor called scutes. There are 27 species of sturgeon worldwide. Two species, green and white sturgeon, are native to California, USA, and are some of the largest animals in San Francisco Bay. Sturgeon populations have declined due to habitat loss, water management, overfishing, poaching, pollution, and climate change. Sturgeon cannot jump over barriers like salmon can, so structures like dams that block water also block sturgeon from reaching their natural spawning habitat farther upstream in the river. Scientists are using new technologies to monitor sturgeon populations and discover the unique behaviors of these dinosaur-era fish in California’s rivers and estuaries.

Early Life History of Fishes in the San Francisco Estuary and Watershed

2004 ◽  
Keyword(s):  
Life History ◽  
San Francisco ◽  
Early Life ◽  
Oncorhynchus Tshawytscha ◽  
San Francisco Estuary ◽  
Sacramento River ◽  
Yolo Bypass ◽  
Species Abundances ◽  
Native Fishes ◽  
Rotary Screw

<em>Abstract.</em>—We examined assemblage patterns of early life stages of fishes for two major tributaries of the upper San Francisco Estuary: (1) Sacramento River channel, and (2) Yolo Bypass, the river’s seasonal floodplain. Over four hydrologically diverse years (1999–2002), we collected 15 species in Yolo Bypass egg and larval samples, 18 species in Yolo Bypass rotary screw trap samples, and 10 species in Sacramento River egg and larval samples. Fishes captured included federally listed species (delta smelt <em>Hypomesus transpacificus </em>and splittail <em>Pogonichthys macrolepidotus</em>) and several game species (American shad <em>Alosa sapidissima</em>, striped bass <em>Morone saxatilis</em>, crappie <em>Pomoxis </em>spp., and Chinook salmon <em>Oncorhynchus tshawytscha</em>). As in other regions of the estuary, alien fish comprised a large portion of the individuals collected in Yolo Bypass (40–93% for egg and larval net samples; 84–98% for rotary screw trap samples) and Sacramento River (80–99% for egg and larval net samples). Overall ranks of species abundances were significantly correlated for Yolo Bypass and Sacramento River, suggesting that each assemblage was controlled by similar major environmental factors. However, species diversity and richness were higher in Yolo Bypass, likely because of a wider variety of habitat types and greater hydrologic variation in the floodplain. In both landscapes, we found evidence that timing of occurrence of native fishes was earlier than aliens, consistent with their life history and our data on adult migration patterns. We hypothesize that Yolo Bypass favors native fishes because the inundation of seasonal floodplain typically occurs early in the calendar year, providing access to vast areas of spawning and rearing habitat with an enhanced food web. Conclusions from this analysis have implications for the management of aquatic biodiversity of tributaries to the San Francisco Estuary and perhaps to other lowland rivers.

scholarly journals Aliens From an Underwater World

2021 ◽  
Vol 9 ◽  
Author(s):  
Pedro Morais ◽  
João Encarnação ◽  
Maria Alexandra Teodósio ◽  
Ester Dias
Keyword(s):  
Invasive Species ◽  
North America ◽  
Alien Species ◽  
San Francisco ◽  
Outer Space ◽  
San Francisco Estuary ◽  
The World ◽  
The Way

About 3.1 billion people around the world live within 100 km of the coastline. If you are one of those people, then you also live near an estuary. What you probably do not know is that many alien species live in this underwater world, and we are not talking about extraterrestrial species from outer space. Are you scared? Well, do not be! These alien species are from planet Earth. In this article, we will tell you what alien species are, why scientists study them, how any species may become an alien, and how a few alien species may become an invasive species. You will also learn how you can help scientists find and track alien species, and how to defeat them. Along the way, we will give examples of alien species living in the San Francisco Estuary in North America, a paradise for hundreds of alien species.

scholarly journals First Record of the Large-Scale Loach Paramisgurnus dabryanus (Cobitidae) in the United States

2018 ◽  
Vol 9 (1) ◽  
pp. 246-254 ◽  
Author(s):  
Joseph E. Kirsch ◽  
Richard F. Feeney ◽  
Alisha Goodbla ◽  
Christopher Hart ◽  
Zachary J. Jackson ◽  
...  
Keyword(s):  
United States ◽  
San Francisco ◽  
Large Scale ◽  
Fish Communities ◽  
The United States ◽  
San Francisco Estuary ◽  
Bifurcation Structure ◽  
Paramisgurnus Dabryanus ◽  
San Joaquin River ◽  
The U.S

Abstract Exotic species have been implicated as a major threat to native freshwater fish communities in the Unites States. The San Francisco Estuary watershed has been recognized as one of the most invaded systems where exotics often dominate the fish community. On October 6, 2014, members of the U.S. Fish and Wildlife Service detected a previously unknown exotic fish in a disconnected pool immediately upstream from the Chowchilla Bifurcation Structure in the San Joaquin River, a major tributary of the San Francisco Estuary. A member of the U.S. Fish and Wildlife Service initially identified the fish as an Oriental Weatherfish Misgurnus anguillicaudatus using external morphological characteristics. We conducted additional fish sampling near the Chowchilla Bifurcation Structure in November 2014 and collected a total of six additional specimens in disconnected pool habitats. Unexpectedly, genetic and meristic techniques revealed that these specimens were Large-Scale Loach Paramisgurnus dabryanus. To our knowledge this is the first confirmed occurrence of Large-Scale Loach in the United States and the suspected pathway of introduction is release from aquaria. Very little is known about the population in the San Joaquin River. We recommend further evaluation of the ecology, distribution, and abundance of Large-Scale Loach to better understand their potential impact on the fish communities of the San Joaquin River and the likelihood of establishment throughout the United States.

Tissue Contaminant Burdens in San Francisco Estuary White Sturgeon (Acipenser transmontanus): Implications for Population Recovery

2017 ◽  
Vol 73 (2) ◽  
pp. 334-347 ◽  
Author(s):  
Deke T. Gundersen ◽  
Steven C. Zeug ◽  
Robert B. Bringolf ◽  
Joseph Merz ◽  
Zachary Jackson ◽  
...  
Keyword(s):  
San Francisco ◽  
San Francisco Estuary ◽  
White Sturgeon ◽  
Acipenser Transmontanus ◽  
Population Recovery

scholarly journals Estuarine Habitat Use by White Sturgeon (Acipenser transmontanus)

2020 ◽  
Vol 18 (4) ◽  
Author(s):  
Oliver Patton ◽  
Veronica Larwood ◽  
Matthew Young
Keyword(s):  
San Francisco ◽  
Water Channel ◽  
Open Water ◽  
San Francisco Estuary ◽  
White Sturgeon ◽  
Acipenser Transmontanus ◽  
Structural Elements ◽  
Estuarine Habitat ◽  
Habitat Gradient ◽  
Variable Water

White Sturgeon (Acipenser transmontanus), a species of concern in the San Francisco Estuary, is in relatively low abundance due to a variety of factors. Patton et al. sought identify the estuarine habitat used by White Sturgeon to aid in the conservation and management of the species locally and across its range. By seasonally sampled sub-adult and adult White Sturgeon in the central estuary using setlines across a habitat gradient representative of three primary structural elements, the authors found that the shallow open-water shoal and deep open-water channel habitats were consistently occupied by White Sturgeon in spring, summer, and fall across highly variable water quality conditions, whereas the shallow wetland channel habitat was essentially unoccupied. In summary, sub-adult and adult White Sturgeon inhabit estuaries in at least spring, summer, and fall and small, shallow wetland channels are relatively unoccupied.

scholarly journals Evaluation of a large-scale flow manipulation to the upper San Francisco Estuary: Response of habitat conditions for an endangered native fish

2020 ◽  
Author(s):  
Ted Sommer ◽  
Rosemary Hartman ◽  
Michal Koller ◽  
Michael Koohafkan ◽  
J. Louise Conrad ◽  
...  
Keyword(s):  
San Francisco ◽  
The United States ◽  
San Francisco Estuary ◽  
Sacramento River ◽  
Habitat Conditions ◽  
Delta Smelt ◽  
Low Salinity ◽  
Low Salinity Water ◽  
Salinity Water ◽  
General Response

AbstractWhile flow is known to be a major driver of estuarine ecosystems, targeted flow manipulations are rare because tidal systems are extremely variable in space and time, and because the necessary infrastructure is rarely available. In summer 2018 we used a unique water control structure in the San Francisco Estuary (SFE) to direct a managed flow pulse into Suisun Marsh, one of the largest contiguous tidal marshes on the west coast of the United States. The action was designed to increase habitat suitability for the endangered Delta Smelt Hypomesus transpacificus, a small osmerid fish endemic to the upper SFE. The approach was to operate the Suisun Marsh Salinity Control Gates (SMSCG) in conjunction with increased Sacramento River tributary inflow to direct an estimated 160 × 106 m3 pulse of low salinity water into Suisun Marsh during August, a critical time period for juvenile Delta Smelt rearing. Three-dimensional modeling showed that directing additional low salinity water into Suisun Marsh (“Flow Action”) substantially increased the area of low salinity habitat for Delta Smelt that persisted beyond the period of SMSCG operations. Field monitoring showed that turbidity and chlorophyll were at higher levels in Suisun Marsh, representing better habitat conditions, than the upstream Sacramento River region throughout the study period. The Flow Action had no substantial effects on zooplankton abundance, nor did Suisun Marsh show enhanced levels of these prey species in comparison to the Sacramento River. Fish monitoring data suggested that small numbers of Delta Smelt colonized Suisun Marsh from the Sacramento River during the Flow Action, further supporting our hypothesis that the Flow Action would benefit this rare species. Our study provides insight into both the potential use of targeted flow manipulations to support endangered fishes such as Delta Smelt, and into the general response of estuarine habitat to flow management.

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