Recent csgc_rp items

Studying gravel bars in rivers to identify what features facilitate groundwater exchanges that create good Chinook salmon spawning habitat

Mon, 8 May 2017 00:00:00 +0000

Studying gravel bars in rivers to identify what features facilitate groundwater exchanges that create good Chinook salmon spawning habitat

Optimizing salt marsh harvest mouse conservation through an investigation of demography, habitat use andmulti-species management

Mon, 8 May 2017 00:00:00 +0000

Optimizing salt marsh harvest mouse conservation through an investigation of demography, habitat use andmulti-species management

Examining the effects of perennial pepper weed on tidalmarsh ecosystems and identifying strategies to stop thenoxious weed’s spread

Mon, 8 May 2017 00:00:00 +0000

Examining the effects of perennial pepper weed on tidalmarsh ecosystems and identifying strategies to stop thenoxious weed’s spread

Determining thermal tolerances of longfin smelt and inland silverside and develop biomarkers of thermal stress using new genomics technology

Mon, 8 May 2017 00:00:00 +0000

Determining thermal tolerances of longfin smelt and inland silverside and develop biomarkers of thermal stress using new genomics technology

Understanding Food Webs in Shallow Nearshore Waters of the Delta

Fri, 24 Oct 2014 00:00:00 +0000

Understanding Food Webs in Shallow Nearshore Waters of the Delta

Salinity Tolerances and Biomarkers of Salt Stress in Longfin and Delta Smelt

Fri, 24 Oct 2014 00:00:00 +0000

Salinity Tolerances and Biomarkers of Salt Stress in Longfin and Delta Smelt

Controls on the Net Carbon Emissions from Restored Wetland Ecosystems

Fri, 24 Oct 2014 00:00:00 +0000

Controls on the Net Carbon Emissions from Restored Wetland Ecosystems

Modeling Wetland Plant Cover to Assess Ecosystems and Bird Habitats

Fri, 24 Oct 2014 00:00:00 +0000

Modeling Wetland Plant Cover to Assess Ecosystems and Bird Habitats

Unraveling Sources of Food Web Support in the Sacramento-San Joaquin Delta’s Marsh Ecosystem

Fri, 24 Oct 2014 00:00:00 +0000

Unraveling Sources of Food Web Support in the Sacramento-San Joaquin Delta’s Marsh Ecosystem

The effects of freshwater flows on the native Olympia oyster in San Francisco Estuary

Mon, 16 Dec 2013 00:00:00 +0000

After heavy winter storms, salinity levels in the San Francisco Estuary can drop precipitously, stressing and sometimes killing organisms such as the native Olympia oyster (Ostrea conchaphila ) and invasive Mediterranean mussel (Mytilus galloprovincialis ).

Phytoplankton and bacteria nutrient use: impacts of nutrient loading on the base of the food web

Mon, 16 Dec 2013 00:00:00 +0000

Treated municipal wastewater contains a form of nitroge known as ammonium. When discharged into waterways, this ammonium may alter phytoplankton (algal) communities and potentially degrade available food resources for zooplankton and other organisms.

Saving San Francisco Bay-Delta native fishes: hatchery management and reinintroduction strategies

Mon, 16 Dec 2013 00:00:00 +0000

Several native fish species in the San Francisco Bay-Delta and Central Valley have experienced dramatic population declines and could realistically go extinct in the wild.

The effects of bifenthrin pesticide on the reproductive health of steelhead under hypersaline conditions.

Mon, 16 Dec 2013 00:00:00 +0000

Salmon and steelhead in the San Francisco Bay-Delta face many challenges, including exposure to pesticides in runoff and municipal wastewater discharges.

Detecting changes at the base of the pelagic food web in the San francisco Estuary.

Mon, 16 Dec 2013 00:00:00 +0000

Since about 2004, populations of delta smelt, longfin smelt, juvenile striped bass, and threadfin shad have dropped significantly in the Sacramento-San Joaquin Delta for no obvious or as yet substantiated reason.

Sacramento River Steelhead: Hatchery vs. Natural Smolt Outmigration

Tue, 9 Oct 2012 00:00:00 +0000

The Sacramento River steelhead trout (Oncorhynchus mykiss) is a threatened species whose numbers are supplemented by the release of captive-bred juveniles. Each year, the Coleman National Fish Hatchery alone produces 600,000 yearling steelhead smolts and releases them into Battle Creek, a tributary of the upper Sacramento River. Smolts are young, silver trout (or salmon) that are ready to migrate to sea for the first time. The hatchery operations are mitigation for loss of natural steelhead in their historic spawning grounds. Coleman is one of several hatcheries in the Sacramento River basin that cultures steel- head for mitigation purposes.

Copper Toxicity in the San Francisco Bay-Delta

Tue, 9 Oct 2012 00:00:00 +0000

San Francisco Bay has high dissolved copper concentrations—relative to nearby coastal waters—that often approach federal water quality standards put in place to protect sensitive marine life. But, how toxic is this copper?

Previous studies by other researchers have suggested that metal-binding compounds known as ligands can “grab up” more than 99.9 percent of the total available dissolved copper in seawater, rendering that copper biologically unavailable. Microorganisms that need trace amounts of copper for growth cannot readily obtain it in its ligand-bound form.

Climate Change and Tidal Marsh Plant Communities in the San Francisco Bay-Delta

Fri, 20 Jul 2012 00:00:00 +0000

Sea levels in California, south of Cape Mendocino, are predicted to rise between 90 and 95 cm between 2000 and 2100, with a range as high as 167 cm and as low as 42 cm, according to a 2012 report by the National Academy of Sciences.

Whatever the ultimate rise in sea level is, it will largely control the fate of tidal marsh habitats in the San Francisco Bay-Delta.

Tidal marshes are wetlands periodically inundated by tidal flows and, unlike mudflats, are vegetated. They provide overwintering and foraging habitat for resident and migratory birds, and are a buffer against floods and storm surge. They also filter and remove pollutants.

Only about 5 to 10 percent of the delta’s historic tidal marshes remain. Most fringe an aging collection of levees. Former wetlands— now diked, behind levees and dry—are sinking and below sea level by as much as 20 m in some places.

Plans are underway to restore thousands of acres of tidal marshes. Whether these marshes are...

Detecting Endocrine Disruption in the Sacramento- San Joaquin Delta

Wed, 11 Jul 2012 00:00:00 +0000

In 2001, the EPA began restricting the use of organophosphate pesticides in bug sprays and strips to protect the health of humans and other mammals. Their main replacement has been another class of highly toxic pesticides known as pyrethroids.

The pyrethroid molecule is basically a chemically stabilized version of the natural pyrethrin molecule found in mums (yes, the flowers). In its modified form, it is more persistent in the environment, more hydrophobic (it will stick to sediment) and more toxic.

Vertebrates, including humans, have enzymes that can break down low doses of pyrethroids but they tend to have endocrine- disrupting effects. Both the pesticides and the compounds produced during their metabolism can potently mimic sex hormones.

Fishes are particularly sensitive to endocrine disrupting compounds (EDCs), due to their size and continuous exposure via contaminated water. Fish exposed to EDCs may display a variety of physiological and behavioral abnormalities,...

Factors Affecting Methylmercury Accumulation in the Food Chain

Tue, 26 Jun 2012 00:00:00 +0000

The common scientific wisdom is that dissolved organic debris (from rotting dead plant material, for example) reduces the biological activity, and hence toxicity, of heavy metals such as mercury. Prior to the start of this project, however, a study showed that organic debris could also sometimes enhance build up of the toxic form of mercury in phytoplankton. This toxic form is called methylmercury (MeHg). It is produced in the aquatic environment by sulfur-reducing bacteria and biomagnifies through aquatic food chains.

What Controls Harmful Algal Blooms and Toxicity in the Sacramento-San Joaquin Delta?

Wed, 20 Jun 2012 00:00:00 +0000

This project shows that harmful algae like it hot. All things being equal, surface water temperature is the best predictor of whether a harmful algal bloom will form in the Sacramento-San Joaquin Delta, though flow dynamics, nutrient pollution and microbial associations also may play a role.

Frequency, Distribution and Ecological Impact of Cryptic Hybrid Invaders: Management Tools for Eradication of Invasive Spartina

Tue, 13 Dec 2011 00:00:00 +0000

Four species of nonindigenous Spartina cordgrass have been introduced to San Francisco Bay. One of them, Spartina alterniflora, from the East Coast, has hybridized with the native S. foliosa and become highly invasive. These hybrids and their backcrosses are problematic to conservation objectives as they colonize nearly every ecological niche of a marsh – high and low marsh elevations, and across a range of salinities and sediment types. Where established, the hybrids inevitably pollen swap with native Spartina, creating yet more hybrids. With time, rare wetlands can be converted into uniform expanses of grass. Efforts to eradicate invasive Spartina have been based largely on visually identifying the most threatening, biggest, tallest and thickest, red-stemmed, big-flowered cordgrass plants and spraying these with herbicide. The strategy has been highly success- ful in reducing the invasion’s size – from about 800 net acres in 2005 to about 50 net acres in 2011....

Predicting the Effects of Climate Change on the Size and Frequency of Floods in the Sacramento-San Joaquin Valley

Wed, 21 Sep 2011 00:00:00 +0000

How might climate change alter California’s risk of floods in the future? Findings from this project suggest that flooding will become more intense in the San Joaquin and (to a lesser extent) Sacramento watersheds by the end of the century, irrespective of whether the climate becomes wetter or drier. More intense flooding appears to be a consequence of several factors—principally bigger storms, more frequent big storms and more days of precipitation falling as rain instead of snow. Moister winter soils, which may be too saturated to absorb added water, also contribute to flooding in some areas.

Genetic Markers for Detecting Population Structure of West Coast Chinook Salmon

Wed, 21 Sep 2011 00:00:00 +0000

Scientists have identified 117 new single nucleotide polymorphisms (SNPs) for detecting the genetic relatedness of Chinook salmon.

The most basic genetic variation possible, a SNP (pronounced “snip”) refers to a single difference in one base pair of a nucleotide. The major outcome of this project is the identification of an optimal panel of 96 SNPs that is capable of detecting both the parentage of hatchery-born Chinook and the origin (i.e., stock) of Chinook caught off California and Oregon.

SNPs are fast becoming the tool of choice for population genetics studies of nonmodel organisms such as Pacific salmon, because of their low rates of error (mutation) and high resolving power. The detailed resolution of SNPs is particularly well suited for studies of anadromous fishes such as Chinook salmon (Oncorhynchus tshawytscha), as their fidelity to their natal rivers leads to a hierarchical population structure. This project demonstrates applications and advantages of...

Plankton Dynamics in the Sacramento-San Joaquin Delta: Long-Term Trends and Trophic Interactions

Wed, 21 Sep 2011 00:00:00 +0000

Based on an analysis of a 37-year time series, zooplankton biomass and species composition appear to have changed profoundly in Suisun Bay and Sacramento-San Joaquin Delta, in response to invasive species introductions and hydrological conditions. Results are consistent with other studies linking a majority of species interactions in the upper San Francisco Estuary to non-native invasions. The Asian clam and several exotic zooplankton species appear to have capitalized, directly and indirectly, on the long drought from 1987 to 1994 and exacerbating water management practices. During this period of sustained high-salinity conditions, larger native copepods – the preferred prey of larval fishes – were replaced by smaller Asian zooplankton, notably Limnoithona tetrapsina, likely introduced via ballast water. In addition to the new species, total zooplankton biomass dropped significantly during the last four decades; however, the pace and timing of the decline does not explain...

Kelp Wrack: Hopping with Life in Ventura County

Mon, 16 May 2011 00:00:00 +0000

The same waves that pound the shore off California also tear large amounts of seaweed from the region’s giant kelp forests and rocky reefs. Much of this drift seaweed, known as wrack, is eventually washed ashore. On many of Southern California’s beaches, tractors will remove this wrack (along with trash and litter) and rake the sand, in a process known as beach grooming.

Kelp Wrack: Hopping with Life in Santa Barbara County

Mon, 16 May 2011 00:00:00 +0000

Kelp Wrack: Hopping with Life in Orange County

Mon, 16 May 2011 00:00:00 +0000

Kelp Wrack: Hopping with Life in San Diego County

Mon, 16 May 2011 00:00:00 +0000

Kelp Wrack: Hopping with Life in Los Angeles County

Mon, 16 May 2011 00:00:00 +0000

Sea Slugs as Brilliant Indicators of Climate Change in Central California

Wed, 27 Apr 2011 00:00:00 +0000

This project examines whether rocky intertidal nudibranchs (brightly colored shallow-water mollusks also known as sea slugs) can be used as fine-scale indicators of inter-annual and decadal-scale climate variability. As part of this research, biologists offer a partial explanation for an observed decline in sea slugs off Central California, and document the climate-induced range shift of one particularly aggressive predatory “killer” sea slug and its effect on intertidal ecology at Duxbury Reef in Marin County. Field studies have led to the discovery of two new species of sea slugs.

The Physics of a "Red Tide" off Huntington Beach

Thu, 7 Apr 2011 00:00:00 +0000

In this project, scientists describe the processes by which a subsurface nearshore algal bloom is carried to the surface, swept closer to the shore and ultimately blocked from entering the surf zone at Huntington Beach in Orange County, California.

Spreading Non-Native Species through the Live-Bait Trade?

Wed, 6 Apr 2011 00:00:00 +0000

Several species of marine worms and crustaceans are routinely imported into California for use as live bait. The most common of these is the ghost shrimp (a translucent crayfish-like burrowing crustacean found in coastal mud flats along the West Coast). The goal of this project was to evaluate some of the potential risks associated with the live-bait trade, in terms of its potential to spread non-native bait spe- cies, their associated parasites, and “hitchhiker” species, which may be present in bait packing materials such as seaweed. A genetics study was also conducted to determine whether importing ghost shrimp from Washington and Oregon to California might “genetically pollute” southern populations.

An Estimate of White Sharks off Central California

Fri, 1 Apr 2011 00:00:00 +0000

Fewer white sharks (Carcharodon carcharias) inhabit the northeast Pacific Ocean than scientists previously thought. The first official count of the iconic marine predator is consistent with genetic studies that have shown a low degree of genetic variability among the animals.

The Role of Symbiotic Bacteria in Iron Acquisition and Algal Bloom Formation

Tue, 1 Mar 2011 00:00:00 +0000

This project seeks to characterize the structure and chemistry of siderophores produced by bacteria associated with bloom-forming dinoflagellates. (Dinoflagellates are a type of algae that swimby whipping tail-like structures known as flagella.) Results illuminate the processes and conditions that may precondition areas for certain kinds of sudden, heavy algal growth and can be used to improve HAB forecasts.

Minimizing Fishmeal in California Yellowtail and White Seabass Feeds

Fri, 11 Feb 2011 00:00:00 +0000

In this project, researchers developed alternative feeds for two high-value marine finfish species, California yellowtail (popular on sushi menus) and white seabass.

A New Tool for Assessing the Potential Disease Impacts of Propagated Marine Fish on Wild Stocks

Fri, 11 Feb 2011 00:00:00 +0000

A growing number of marine finfishes are currently under investigation as candidates for artificial propagation – for stocking, endangered species restoration, and human consumption. This project addresses a leading concern about placing hatchery-born fish into an environment where they either directly or indirectly co-mingle with wild species – the potential to introduce or spread disease.

Probing the Medical Potential of Microbial Marine Life

Fri, 4 Feb 2011 00:00:00 +0000

The purpose of this project was to explore the biomedical potential of a group of marine bacteria closely related to the medically prolific group of soil genomes of two marine actinomycetes.

Roundworms as Bioindicators of Sediment Ecology at Bolsa Chica Wetlands

Tue, 1 Feb 2011 00:00:00 +0000

Nematodes, also known as roundworms, are among the most abundant groups of animals on the planet. If you had pinworms as a child, you’ve experienced nematodes firsthand – and are not alone, as at any given time, about a third of the world’s population is believed to be infected by some kind of nematode para- site. Nematodes, many species of which are not parasitic, are also incredibly common denizens of coastal sediments, and an important source of nourishment for shellfish and bigger worms, which themselves are forage species for other animals. Because of this, roundworms are critical components of the coastal food web, and hence a meaningful “bottom-up” indicator of coastal ecosystem functioning.

2007-2010 Ocean Protection Council/California Sea Grant Research

Mon, 31 Jan 2011 00:00:00 +0000

California’s Ocean Protection Council (OPC) was created in accordance with the 2004 California Ocean Protection Act to improve the management and protection of ocean and coastal resources and ecosystems. One of the many ways the OPC achieves this purpose is by supporting innovative research that directly informs and improves the stewardship of ocean resources through a partnership with California Sea Grant.

Developing a Vaccine to Prevent Streptococcus iniae Infection in Fish

Fri, 28 Jan 2011 00:00:00 +0000

With Sea Grant support, medical researchers helped fish growers develop a control method for a deadly bacterial infection that costs the global aquaculture industry about $100 million annually.

Tracking Sooty Shearwaters to Identify Critical At-Sea Habitats in the California Current

Sat, 1 Jan 2011 00:00:00 +0000

Scientists tracked sooty shearwaters (Puffinus griseus) within the California Current ecosystem during their summertime feeding period and used the data to locate aggregations of prey species such as anchovy, sardine, krill and squid. Findings are assisting in identifying critical at-sea habitats for the shearwaters and are of direct relevance to developing ecosystem-based management plans of forage species, upon which seabirds and other marine species rely.

Bacterial and Protozoal Contamination of Nearshore Marine Environments

Thu, 30 Sep 2010 00:00:00 +0000

In this project, scientists show that coastal dairies can reduce pathogen pollution in runoff through a combination of inexpensive, adaptable management practices, such as by planting barley and rye grasses around lots holding young calves. The grasses help filter and trap pathogens and are called “vegetative buffer strips.”

The project also demonstrates the utility of mussels in concen- trating and hence detecting the fecal parasite Cryptosporidium. Sentinel mussels were used to show the sporadic yet widespread presence of the parasite in coastal Central California, irrespective of proximity to livestock runoff and/or human sewage.

Addressing Stakeholder Concerns: Pests and Pest Control in the Sacramento River Conservation Area

Tue, 27 Jul 2010 00:00:00 +0000

The Nature Conservancy and U.S. Fish and Wildlife Service are leading efforts to restore an ecologically viable 100-mile stretch of the Sacramento River, between Red Bluff and Colusa. Within the Sacramento River Conservation Area, the river will be allowed to do what rivers normally do – meander, flood, erode and deposit sediment. Native vegetation will also be re-planted to help create much needed habitat (indeed refuge) for some of the region’s more than 250 indigenous animal species, including yellow-billed cuckoos, river otters, Chinook salmon and green sturgeon, as well as threatened bat and insect species. The restored wildlife area will also provide valuable educational and recreational opportunities for school-age children and the general public.

Route-Specific Survival of Juvenile Salmon Migrating through the Sacramento-San Joaquin Delta

Wed, 7 Jul 2010 00:00:00 +0000

How effective is closing the gates of the Delta Cross Channel in preventing young salmon from entering the interior of the Sacramento-San Joaquin Delta, where water diversions occur and salmon mortalities are high?What other factors influence a migrating salmon’s chances of making it to sea? This project examined these questions by tagging and tracking more than a thousand juvenile Chinook salmon released into the Sacramento River. The data were used to estimate salmon survival rates along different migration routes and their relation to the operation of the cross channel, flow rates and tides, among other things. A subsequent model has been developed for predicting the effects of future water management actions on salmon.

Gene Expression Predictors of Summer Mortality Syndrome in Pacific Oysters

Wed, 7 Jul 2010 00:00:00 +0000

Native to Japan, the Pacific oyster (Crassostrea gigas) is a major component of the U.S. shellfish industry, hailed as Washington’s most valuable bivalve. NOAA estimates that from 1984 to 2005, oyster farming generated approximately $96.2 million annually (not limited to the Pacific oyster).

Pepperweed's Ecosystem Impacts in Suisun Marsh: Methods for Control

Wed, 7 Jul 2010 00:00:00 +0000

Perennial pepperweed (Lepidium latifolium) is an aggressive, non-native herbaceous weed displacing native vegetation in marshes, floodplains, prairies and rangeland throughout California. You can even find it growing along roadsides and highways. But does the plant’s ubiquity really mean it is an ecological problem warranting costly eradication efforts?

Determining the Factors Controlling Site Invasibility to Lepidium latifolium

Wed, 2 Jun 2010 00:00:00 +0000

In this project, the Delta Science Fellow compiled several years of airborne hyperspectral imaging data to produce detailed maps of the distribution of the invasive perennial pepperweed (Lepidium latifolium) at sites in the Sacramento San Francisco Bay-Delta.

From the maps, inferences were made about the habitats that attract this noxious invasive plant, facilitate its spread and are vulnerable to future infestation. The Solano Land Trust, a nonprofit that purchases land for preservation, is using the maps to

more strategically and cost-effectively contain existing infestations and prevent colonization of presently weed-free places.

Perennial pepperweed is a long-lived herbaceous member of the mustard family, native to southeastern Europe and Asia and now common in the western United States. It forms large, dense stands with extensive root systems, displacing native vegetation, reducing native habitat for wildlife. Established populations are difficult to...

Prey Selection of Larval and Juvenile Planktivorous Fish in the San Francisco Estuary

Wed, 2 Jun 2010 00:00:00 +0000

This project examined the effects of the introduced Asian copepod Limnoithona tetraspina, the dominant zooplankton species in brackish waters of the San Francisco Estuary, on the diets of larval and juvenile delta smelt (Hypomesus transpacificus) and striped bass (Morone saxatilis).

Otolith Growth and Microchemistry to Determine Variability in Recruitment Success of Delta Smelt

Wed, 17 Mar 2010 00:00:00 +0000

This project employed otolith geochemistry to study the recruit- ment patterns and growth rates of delta smelt before and during the Pelagic Organism Decline (POD) in the San Francisco Bay-Delta. The delta smelt was selected as the target species for the analysis because of its imperiled status (it is on both state and federal endangered species lists) and because it is one of several pelagic species in the Bay-Delta whose numbers have plummeted since the 2002–04 period, during which time water exports rose by 30 percent. The delta smelt, in many ways, can be thought of as the proverbial canary in the coal mine — a species whose status mirrors the ecological health of its surroundings.

Exercising Juvenile Marine Finfish to Enhance Growth and Lower Stress

Fri, 5 Feb 2010 00:00:00 +0000

It sounds crazy, exercising fish to make them gain weight. But that is exactly what happens with juvenile California yellowtail, a once common species off California and Mexico fished heavily by the Japanese. Not surprisingly, given parallels with human health, ex- ercise also alleviates stress in fish, as measured by bloodstream levels of cortisol, the same stress hormone in humans. The findings have led a California Department of Fish and Game biologist to consider rearing juvenile endangered salmon in raceways, in the hopes of boosting their post-release survival.

Collecting Sea Palms: Planning for Sustainable Use in a Variable Environment

Mon, 25 Jan 2010 00:00:00 +0000

Up until recently, few in mainstream America ate seaweed, or wanted to. Edible seaweed was a concept relegated to, for all practical purposes, Asian and Native American cultures and cuisines. Times have changed. Today, bulk bins at health food stores overflow with kombu, nori, wakame, dulse and all sorts of other kinds of “sea vegetables,” while high- end vegetarian restaurants offer entrées as innovative (and unexpected) as seaweed strudel.

The allure for health-conscious Americans is obvious: seaweeds are high in iodine, iron, phosphorous, potassium, manganese, copper and zinc, as well as vitamins A, B, C, E and K. They are low in calories, and low on the food chain. Although not technically plants, in most people’s minds, seaweed counts toward the “fruits and vegetables” part of the food pyramid.

Assessing Connectivity of Red Sea Urchin Populatins Using New Genetic Tools