LEETOWN, W.Va. — Great Lakes fish in the salmon family that rely on the fish “alewife” as part of their diet face a major obstacle in restoring naturally reproducing populations, according to new U.S. Geological Survey research published in the journal Fish and Shellfish Immunology.
For more than a decade researchers have been trying to unravel the mystery of why Lake Trout and other salmonids that consume alewife produce spawn that die young. Although researchers have recognized the connection between thiamine and the death of the young fish for a decade, the new study provides an additional clue; fish that survive the initial impact of thiamine deficiency are experiencing changes in immune function that resemble those occurring in humans with inflammatory diseases.
Early Mortality Syndrome, or EMS, results in embryonic mortality in salmon, steelhead trout, brown trout, lake trout, and Chinook salmon. The symptoms of EMS include loss of equilibrium, swimming in a spiral pattern, lethargy, hyper-excitability, hemorrhage and death, which occurs between hatching and first feeding.
“Vitamin B1, or Thiamine, is an essential nutrient that animals must obtain through their diet,” said Chris Ottinger, a USGS immunologist and lead author of the study. “We found that alewives, one of the main diets of many Great Lakes fish, contains an enzyme called “thiaminase” that destroys the thiamine in fish that consume them. The lack of B1 leads to Early Mortality Syndrome as well as the newly reported immune dysfunctions that may be perpetuating infectious diseases in this fish community.”
Alewives were introduced to the Great Lakes as food fish for the species such as lake trout and the introduced Pacific salmon.
“There is some debate as to whether the thiaminase that is obtained through the consumption of the alewives is coming directly from the fish or from bacteria associated with the fish,” said Ottinger. “Either way the fish that eats the alewives becomes thiamine deficient through the destruction of the thiamine they obtain in their diet resulting in EMS as well the immune dysfunctions we have demonstrated.”
Thiamine is essential for energy production in cells, normal nerve function and also is an antioxidant. Other dysfunctions associated with Great Lakes salmonids consumption of alewives include changes in behavior and reduced ability to capture prey.
"In vitro immune function in thiamine-replete and-depleted lake trout (Salvelinus namaycush)" is available online in the journal Fish & Shellfish Immunology by C. A. Ottinger, D. C. Honeyfield, C. L. Densmorea, and L. R. Iwanowicz.
A new DNA protocol developed by the U.S. Geological Survey helps biologists distinguish between native and invasive species of aquatic vegetation that have almost identical appearances. Until now, measuring the dispersal of these various invasive plants has been hampered by confusion about where and when the plants arrived.
Invasive aquatic plants from Korea, Brazil, and the Indian subcontinent have been spreading through U.S. waterways for decades. The new DNA protocol will help biologists identify species, track their progress, and provide facts to local managers who can develop appropriate control measures.
“When invasive plants appear in a body of water, local people naturally are alarmed” said Nancy Rybicki, the USGS biologist who teamed up with molecular biologists to develop the new DNA testing technique. “Enormous amounts of money are spent on control. Some species may look very nearly identical, but they have unique reproductive and growth characteristics. Identification, the first step for control or eradication, needs to be precise.”
Co-author and previous USGS employee, Mary Voytek has had extensive experience with the use of molecular tools for microbial identification. In the case of microbes, there are established standards for identification using portions of an organism’s DNA. Not so with plants. It was difficult to know where to start.
The authors were able to develop a simple protocol that was verified on voucher specimens and tested on numerous plant samples. The environmental implications of the results were clear as new information on the range and recent history of these invasive species was revealed.
Using this new protocol, Rybicki determined that hydrilla arrived in both the Potomac River and Chesapeake Bay earlier than previously thought, a finding that revises earlier ideas of how it was first introduced into the area.
The authors found that hydrilla was in the Potomac River in 1976. Thus, the original introduction of hydrilla to the Potomac was not from National Park Service experiments conducted in 1980 at Dyke Marsh on the tidal Potomac River as previously thought. It is probable that hydrilla was already present, but was misidentified. It may still be undiscovered in many locations today.
The two biotypes of hydrilla, one first introduced into Florida and the other first introduced into Washington, DC, are both spreading toward Canada, well beyond their predicted range.
“We anticipate that hydrilla will continue to move into colder regions, including, the Great Lakes, where a native plant called elodea is common,” Rybicki explained. “Without DNA verification, misidentification of the two plants is likely.”
DNA analysis to identify underwater grasses, a service provided at the USGS lab in Reston, VA, enables quick identification of these species. Future use of DNA analysis will likely reveal that many more misidentifications have occurred and are waiting to be discovered. Positive identification is the key first step in any discussion of management options to deal with invasive species.
Rybicki, N. B., Kirshtein, J. D., and Voytek, M. A., 2013, Molecular techniques to distinguish morphologically similar Hydrilla verticillata, Egeria densa, Elodea nuttallii, and Elodea canadensis, Journal of Aquatic Plant Management, v. 51, p. 94 -102.
Corresponding author, email@example.com
To initiate new research projects on mineral resources important to the nation's economy, security, and land-use decisions, the U.S. Geological Survey has awarded $208,000 in research grants.
Recipients of the 2014 USGS Mineral Resources External Research Program grants will study rare earth elements in Colorado; scarce metals in the U.S. and global economies; and nickel, copper and platinum deposits in the Lake Superior region. These and other USGS mineral research projects are intended to provide science that can help the nation to avoid supply disruptions for minerals that are critical for national security and the economy, while reducing the effects of mining and other activities on the environment.
A Rare Concentration of Rare Earth Elements Near Jamestown, Colorado
Julien Allaz of the University of Colorado, Boulder will investigate an unusual concentration of rare earth elements in veins near Jamestown, Colorado. These veins were first studied more than 70 years ago, but not since. Allaz will investigate the origin of these veins using state-of-the-art methods. Rare earth elements are essential for an expanding array of high-technology applications, for many alternative energy technologies and for a number of key defense systems, but they are rarely concentrated into mineable ore deposits. Understanding the origin of these veins will help us to assess where similar concentrations of rare earth elements occur.
Understanding the Life Cycle of Scarce Metals in the U.S. and Global Economies
Thomas Graedel of Yale University will lead a team of researchers to characterize the materials flow of four scarce metals: gallium, germanium, rhenium, and tungsten. While similar studies have been conducted for major metals such as iron and copper, no such study has been done for these scarce metals, which are used to make aircraft engines, medical equipment, fiber optics, solar technology, consumer electronics, and lighting. This study will help to quantify potential supply strengths and weaknesses, to manage metal use more wisely, and to protect the environment.
How Did Copper Deposits Form in Sedimentary Rocks in Northern Wisconsin and Michigan
John Ridley of Colorado State University will investigate the nature and extent of fluids that transported and deposited copper in the Nonesuch Formation of northern Wisconsin and Michigan. Though two deposits, Copperwood and White Pine, occur in the Nonesuch, the fluid flow associated with these types of copper deposits is typically much more extensive than the deposits themselves. Copper has long been the key to improved living conditions. Today, nearly every building and house in the U.S. contains copper. It is used in plumbing, electrical wiring, cars, cell phones, and in wind turbines. This research will help evaluate the potential for similar copper deposits in the nation’s mid-continent region.
Determining the Source of Nickel, Copper and Platinum in Deposits of the Lake Superior Region
Edward Ripley and Chusi Li of Indiana University will research the source of nickel, copper and platinum group metals in the Lake Superior region of Minnesota and Michigan. They will apply state-of-the-art copper isotope analysis to determine if the metals originated from igneous rock intrusions in which they are now concentrated or from sedimentary rocks that surround the intrusions. Platinum group metals are used to reduce motor vehicle emissions and in technology. Nickel is used to produce strong alloys and stainless steel. This research project will help to assess and explore for deposits in similar geologic environments in the mid-continent region and elsewhere.
The MRERP invited research proposals that addressed the following topics:
- The Mid-continent Rift of the U.S.—Multidisciplinary studies to image and characterize the mineral resource potential of this significant crustal feature.
- Alaska as a mineral resource frontier—Core science investigations as a foundation for documenting mineral resource potential
- Hyperspectral imaging or other geophysical investigations of selected regions of the U.S.—State-of-the-art tools for mineral resource and mineral environmental investigations
- Materials flow studies—Investigations to address supply chain analysis (including risk analysis) and sustainable mineral supplies
- Critical Mineral Resources—Research to better understand the genesis and regional controls on the distribution of critical mineral-bearing systems. For the purpose of this solicitation, critical mineral commodities are defined as follows (in alphabetical order): cobalt, gallium, indium, lithium, niobium, platinum group elements, rare earth elements, rhenium, tantalum, and tellurium.
USGS accepted proposals from academia, State agencies, industry, or other private sector organizations and scientists. Visit the USGS Mineral Resources External Research Program for more information.
The USGS Mineral Resources Program delivers unbiased science and information to understand mineral resource potential, production, consumption, and how minerals interact with the environment.
The U.S. Geological Survey will award up to $5 million in grants for earthquake hazards research in 2015.
“The grants offered through the USGS Earthquake Hazards Program are an established and long-standing effort that have proven to be a success every year, with talented, scientific applicants who significantly contribute to the advancement of earthquake research,” said Bill Leith, USGS Senior Science Advisor for Earthquake and Geologic Hazards. “Every year we are rewarded by innovative proposals from across the country, so we encourage the continued submission of new ideas to help earthquake science evolve and, ultimately, reduce earthquake losses.”
Interested researchers can apply online at GRANTS.GOV under funding opportunity number G14AS00036. Applications are due May 22, 2014.
Each year the USGS awards earthquake hazards research grants to universities, state geological surveys, and private institutions. Past projects included investigating the Central Virginia Seismic Zone to develop a better understanding of this active seismic zone; examining the paleoseismic record in the Prince William Sound area of Alaska to characterize earthquakes prior to the Great Alaska Earthquake of 1964 to better understand future earthquakes in this hazard-prone area; and using GPS to measure ground deformation in the greater Las Vegas area and provide information on how faults will rupture in large, damaging earthquakes.
A complete list of funded projects and reports can be found on the USGS Earthquake Hazards Program external research support website.